Initial commit of version 2.1.

.vscode/settings.json

@@ -0,0 +1,18 @@
+{
+    "cSpell.words": [
+        "actuals",
+        "Analyser",
+        "Denoter",
+        "DENOTERS",
+        "Deryck",
+        "geteol",
+        "getint",
+        "maxint",
+        "notgreater",
+        "notless",
+        "puteol",
+        "putint",
+        "Vname"
+    ],
+    "java.configuration.updateBuildConfiguration": "automatic"
+}

Triangle.AbstractMachine.Disassembler/pom.xml

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+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>triangle.tools</groupId>
+  <artifactId>triangle-disassembler</artifactId>
+  <version>2.1</version>
+  <parent>
+    <groupId>triangle.tools</groupId>
+    <artifactId>triangle-tools</artifactId>
+    <version>2.1</version>
+    <relativePath>../</relativePath>
+  </parent>
+  <dependencies>
+    <dependency>
+      <groupId>triangle.tools</groupId>
+      <artifactId>triangle-abstractmachine</artifactId>
+      <version>2.1</version>
+    </dependency>
+  </dependencies>
+</project>

Triangle.AbstractMachine.Disassembler/src/main/java/Triangle/AbstractMachine/Disassembler.java

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+/*
+ * @(#)Disassembler.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractMachine;
+
+import java.io.DataInputStream;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+/**
+ * Disassembles the TAM code in the given file, and displays the
+ * instructions on standard output.
+ *
+ * For example:
+ *
+ * <pre>
+ *   java TAM.Disassembler obj.tam
+ * </pre>
+ *
+ * <p>
+ * Copyright 1991 David A. Watt, University of Glasgow<br>
+ * Copyright 1998 Deryck F. Brown, The Robert Gordon University<br>
+ * </p>
+ *
+ */
+
+public class Disassembler {
+
+      static String objectName;
+
+      static int CT;
+
+      /**
+       * Writes the r-field of an instruction in the form "l<I>reg</I>r", where
+       * l and r are the bracket characters to use.
+       *
+       * @param leftbracket  the character to print before the register.
+       * @param r            the number of the register.
+       * @param rightbracket the character to print after the register.
+       */
+      private static void writeR(char leftbracket, int r, char rightbracket) {
+
+            System.out.print(leftbracket);
+            switch (r) {
+                  case Machine.CBr:
+                        System.out.print("CB");
+                        break;
+                  case Machine.CTr:
+                        System.out.print("CT");
+                        break;
+                  case Machine.PBr:
+                        System.out.print("PB");
+                        break;
+                  case Machine.PTr:
+                        System.out.print("PT");
+                        break;
+                  case Machine.SBr:
+                        System.out.print("SB");
+                        break;
+                  case Machine.STr:
+                        System.out.print("ST");
+                        break;
+                  case Machine.HBr:
+                        System.out.print("HB");
+                        break;
+                  case Machine.HTr:
+                        System.out.print("HT");
+                        break;
+                  case Machine.LBr:
+                        System.out.print("LB");
+                        break;
+                  case Machine.L1r:
+                        System.out.print("L1");
+                        break;
+                  case Machine.L2r:
+                        System.out.print("L2");
+                        break;
+                  case Machine.L3r:
+                        System.out.print("L3");
+                        break;
+                  case Machine.L4r:
+                        System.out.print("L4");
+                        break;
+                  case Machine.L5r:
+                        System.out.print("L5");
+                        break;
+                  case Machine.L6r:
+                        System.out.print("L6");
+                        break;
+                  case Machine.CPr:
+                        System.out.print("CP");
+                        break;
+            }
+            System.out.print(rightbracket);
+      }
+
+      /**
+       * Writes a void n-field of an instruction.
+       */
+      private static void blankN() {
+            System.out.print("      ");
+      }
+
+      // Writes the n-field of an instruction.
+      /**
+       * Writes the n-field of an instruction in the form "(n)".
+       *
+       * @param n the integer to write.
+       */
+      private static void writeN(int n) {
+            System.out.print("(" + n + ") ");
+            if (n < 10)
+                  System.out.print("  ");
+            else if (n < 100)
+                  System.out.print(" ");
+      }
+
+      /**
+       * Writes the d-field of an instruction.
+       *
+       * @param d the integer to write.
+       */
+      private static void writeD(int d) {
+            System.out.print(d);
+      }
+
+      /**
+       * Writes the name of primitive routine with relative address d.
+       *
+       * @param d the displacment of the primitive routine.
+       */
+      private static void writePrimitive(int d) {
+            switch (d) {
+                  case Machine.idDisplacement:
+                        System.out.print("id      ");
+                        break;
+                  case Machine.notDisplacement:
+                        System.out.print("not     ");
+                        break;
+                  case Machine.andDisplacement:
+                        System.out.print("and     ");
+                        break;
+                  case Machine.orDisplacement:
+                        System.out.print("or      ");
+                        break;
+                  case Machine.succDisplacement:
+                        System.out.print("succ    ");
+                        break;
+                  case Machine.predDisplacement:
+                        System.out.print("pred    ");
+                        break;
+                  case Machine.negDisplacement:
+                        System.out.print("neg     ");
+                        break;
+                  case Machine.addDisplacement:
+                        System.out.print("add     ");
+                        break;
+                  case Machine.subDisplacement:
+                        System.out.print("sub     ");
+                        break;
+                  case Machine.multDisplacement:
+                        System.out.print("mult    ");
+                        break;
+                  case Machine.divDisplacement:
+                        System.out.print("div     ");
+                        break;
+                  case Machine.modDisplacement:
+                        System.out.print("mod     ");
+                        break;
+                  case Machine.ltDisplacement:
+                        System.out.print("lt      ");
+                        break;
+                  case Machine.leDisplacement:
+                        System.out.print("le      ");
+                        break;
+                  case Machine.geDisplacement:
+                        System.out.print("ge      ");
+                        break;
+                  case Machine.gtDisplacement:
+                        System.out.print("gt      ");
+                        break;
+                  case Machine.eqDisplacement:
+                        System.out.print("eq      ");
+                        break;
+                  case Machine.neDisplacement:
+                        System.out.print("ne      ");
+                        break;
+                  case Machine.eolDisplacement:
+                        System.out.print("eol     ");
+                        break;
+                  case Machine.eofDisplacement:
+                        System.out.print("eof     ");
+                        break;
+                  case Machine.getDisplacement:
+                        System.out.print("get     ");
+                        break;
+                  case Machine.putDisplacement:
+                        System.out.print("put     ");
+                        break;
+                  case Machine.geteolDisplacement:
+                        System.out.print("geteol  ");
+                        break;
+                  case Machine.puteolDisplacement:
+                        System.out.print("puteol  ");
+                        break;
+                  case Machine.getintDisplacement:
+                        System.out.print("getint  ");
+                        break;
+                  case Machine.putintDisplacement:
+                        System.out.print("putint  ");
+                        break;
+                  case Machine.newDisplacement:
+                        System.out.print("new     ");
+                        break;
+                  case Machine.disposeDisplacement:
+                        System.out.print("dispose ");
+                        break;
+            }
+      }
+
+      /**
+       * Writes the given instruction in assembly-code format.
+       *
+       * @param instr the instruction to display.
+       */
+      private static void writeInstruction(Instruction instr) {
+
+            switch (instr.op) {
+                  case Machine.LOADop:
+                        System.out.print("LOAD  ");
+                        writeN(instr.n);
+                        writeD(instr.d);
+                        writeR('[', instr.r, ']');
+                        break;
+
+                  case Machine.LOADAop:
+                        System.out.print("LOADA ");
+                        blankN();
+                        writeD(instr.d);
+                        writeR('[', instr.r, ']');
+                        break;
+
+                  case Machine.LOADIop:
+                        System.out.print("LOADI ");
+                        writeN(instr.n);
+                        break;
+
+                  case Machine.LOADLop:
+                        System.out.print("LOADL ");
+                        blankN();
+                        writeD(instr.d);
+                        break;
+
+                  case Machine.STOREop:
+                        System.out.print("STORE ");
+                        writeN(instr.n);
+                        writeD(instr.d);
+                        writeR('[', instr.r, ']');
+                        break;
+
+                  case Machine.STOREIop:
+                        System.out.print("STOREI");
+                        writeN(instr.n);
+                        break;
+
+                  case Machine.CALLop:
+                        System.out.print("CALL  ");
+                        if (instr.r == Machine.PBr) {
+                              blankN();
+                              writePrimitive(instr.d);
+                        } else {
+                              writeR('(', instr.n, ')');
+                              System.out.print("  ");
+                              writeD(instr.d);
+                              writeR('[', instr.r, ']');
+                        }
+                        break;
+
+                  case Machine.CALLIop:
+                        System.out.print("CALLI ");
+                        break;
+
+                  case Machine.RETURNop:
+                        System.out.print("RETURN");
+                        writeN(instr.n);
+                        writeD(instr.d);
+                        break;
+
+                  case Machine.PUSHop:
+                        System.out.print("PUSH  ");
+                        blankN();
+                        writeD(instr.d);
+                        break;
+
+                  case Machine.POPop:
+                        System.out.print("POP   ");
+                        writeN(instr.n);
+                        writeD(instr.d);
+                        break;
+
+                  case Machine.JUMPop:
+                        System.out.print("JUMP  ");
+                        blankN();
+                        writeD(instr.d);
+                        writeR('[', instr.r, ']');
+                        break;
+
+                  case Machine.JUMPIop:
+                        System.out.print("JUMPI ");
+                        break;
+
+                  case Machine.JUMPIFop:
+                        System.out.print("JUMPIF");
+                        writeN(instr.n);
+                        writeD(instr.d);
+                        writeR('[', instr.r, ']');
+                        break;
+
+                  case Machine.HALTop:
+                        System.out.print("HALT  ");
+            }
+      }
+
+      /**
+       * Writes all instructions of the program in code store.
+       */
+      private static void disassembleProgram() {
+            for (int addr = Machine.CB; addr < CT; addr++) {
+                  System.out.print(addr + ":  ");
+                  writeInstruction(Machine.code[addr]);
+                  System.out.println();
+            }
+      }
+
+      // LOADING
+
+      /**
+       * Loads the TAM object program into code store from the named file.
+       *
+       * @param objectName the name of the file containing the program.
+       */
+      static void loadObjectProgram(String objectName) {
+
+            FileInputStream objectFile = null;
+            DataInputStream objectStream = null;
+
+            int addr;
+            boolean finished = false;
+
+            try {
+                  objectFile = new FileInputStream(objectName);
+                  objectStream = new DataInputStream(objectFile);
+
+                  addr = Machine.CB;
+                  while (!finished) {
+                        Machine.code[addr] = Instruction.read(objectStream);
+                        if (Machine.code[addr] == null)
+                              finished = true;
+                        else
+                              addr = addr + 1;
+                  }
+                  CT = addr;
+                  objectFile.close();
+            } catch (FileNotFoundException s) {
+                  CT = Machine.CB;
+                  System.err.println("Error opening object file: " + s);
+            } catch (IOException s) {
+                  CT = Machine.CB;
+                  System.err.println("Error reading object file: " + s);
+            }
+      }
+
+      // DISASSEMBLE
+
+      public static void main(String[] args) {
+            System.out.println("********** TAM Disassembler (Sun Version 2.1) **********");
+
+            if (args.length == 1)
+                  objectName = args[0];
+            else
+                  objectName = "obj.tam";
+
+            loadObjectProgram(objectName);
+            disassembleProgram();
+      }
+}

Triangle.AbstractMachine.Interpreter/pom.xml

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+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>triangle.tools</groupId>
+  <artifactId>triangle-interpreter</artifactId>
+  <version>2.1</version>
+  <parent>
+    <groupId>triangle.tools</groupId>
+    <artifactId>triangle-tools</artifactId>
+    <version>2.1</version>
+    <relativePath>../</relativePath>
+  </parent>
+  <dependencies>
+    <dependency>
+      <groupId>triangle.tools</groupId>
+      <artifactId>triangle-abstractmachine</artifactId>
+      <version>2.1</version>
+    </dependency>
+  </dependencies>
+</project>

Triangle.AbstractMachine.Interpreter/src/main/java/Triangle/AbstractMachine/Interpreter.java

@@ -0,0 +1,620 @@
+/*
+ * @(#)Interpreter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractMachine;
+
+import java.io.DataInputStream;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
+public class Interpreter {
+
+  static String objectName;
+
+  // DATA STORE
+
+  static int[] data = new int[1024];
+
+  // DATA STORE REGISTERS AND OTHER REGISTERS
+
+  final static int CB = 0,
+      SB = 0,
+      HB = 1024; // = upper bound of data array + 1
+
+  static int CT, CP, ST, HT, LB, status;
+
+  // status values
+  final static int running = 0, halted = 1, failedDataStoreFull = 2, failedInvalidCodeAddress = 3,
+      failedInvalidInstruction = 4, failedOverflow = 5, failedZeroDivide = 6,
+      failedIOError = 7;
+
+  static long accumulator;
+
+  static int content(int r) {
+    // Returns the current content of register r,
+    // even if r is one of the pseudo-registers L1..L6.
+
+    switch (r) {
+      case Machine.CBr:
+        return CB;
+      case Machine.CTr:
+        return CT;
+      case Machine.PBr:
+        return Machine.PB;
+      case Machine.PTr:
+        return Machine.PT;
+      case Machine.SBr:
+        return SB;
+      case Machine.STr:
+        return ST;
+      case Machine.HBr:
+        return HB;
+      case Machine.HTr:
+        return HT;
+      case Machine.LBr:
+        return LB;
+      case Machine.L1r:
+        return data[LB];
+      case Machine.L2r:
+        return data[data[LB]];
+      case Machine.L3r:
+        return data[data[data[LB]]];
+      case Machine.L4r:
+        return data[data[data[data[LB]]]];
+      case Machine.L5r:
+        return data[data[data[data[data[LB]]]]];
+      case Machine.L6r:
+        return data[data[data[data[data[data[LB]]]]]];
+      case Machine.CPr:
+        return CP;
+      default:
+        return 0;
+    }
+  }
+
+  // PROGRAM STATUS
+
+  static void dump() {
+    // Writes a summary of the machine state.
+    int addr, staticLink, dynamicLink,
+        localRegNum;
+
+    System.out.println("");
+    System.out.println("State of data store and registers:");
+    System.out.println("");
+    if (HT == HB)
+      System.out.println("            |--------|          (heap is empty)");
+    else {
+      System.out.println("       HB-->");
+      System.out.println("            |--------|");
+      for (addr = HB - 1; addr >= HT; addr--) {
+        System.out.print(addr + ":");
+        if (addr == HT)
+          System.out.print(" HT-->");
+        else
+          System.out.print("      ");
+        System.out.println("|" + data[addr] + "|");
+      }
+      System.out.println("            |--------|");
+    }
+    System.out.println("            |////////|");
+    System.out.println("            |////////|");
+    if (ST == SB)
+      System.out.println("            |--------|          (stack is empty)");
+    else {
+      dynamicLink = LB;
+      staticLink = LB;
+      localRegNum = Machine.LBr;
+      System.out.println("      ST--> |////////|");
+      System.out.println("            |--------|");
+      for (addr = ST - 1; addr >= SB; addr--) {
+        System.out.print(addr + ":");
+        if (addr == SB)
+          System.out.print(" SB-->");
+        else if (addr == staticLink) {
+          switch (localRegNum) {
+            case Machine.LBr:
+              System.out.print(" LB-->");
+              break;
+            case Machine.L1r:
+              System.out.print(" L1-->");
+              break;
+            case Machine.L2r:
+              System.out.print(" L2-->");
+              break;
+            case Machine.L3r:
+              System.out.print(" L3-->");
+              break;
+            case Machine.L4r:
+              System.out.print(" L4-->");
+              break;
+            case Machine.L5r:
+              System.out.print(" L5-->");
+              break;
+            case Machine.L6r:
+              System.out.print(" L6-->");
+              break;
+          }
+          staticLink = data[addr];
+          localRegNum = localRegNum + 1;
+        } else
+          System.out.print("      ");
+        if ((addr == dynamicLink) && (dynamicLink != SB))
+          System.out.print("|SL=" + data[addr] + "|");
+        else if ((addr == dynamicLink + 1) && (dynamicLink != SB))
+          System.out.print("|DL=" + data[addr] + "|");
+        else if ((addr == dynamicLink + 2) && (dynamicLink != SB))
+          System.out.print("|RA=" + data[addr] + "|");
+        else
+          System.out.print("|" + data[addr] + "|");
+        System.out.println("");
+        if (addr == dynamicLink) {
+          System.out.println("            |--------|");
+          dynamicLink = data[addr + 1];
+        }
+      }
+    }
+    System.out.println("");
+  }
+
+  static void showStatus() {
+    // Writes an indication of whether and why the program has terminated.
+    System.out.println("");
+    switch (status) {
+      case running:
+        System.out.println("Program is running.");
+        break;
+      case halted:
+        System.out.println("Program has halted normally.");
+        break;
+      case failedDataStoreFull:
+        System.out.println("Program has failed due to exhaustion of Data Store.");
+        break;
+      case failedInvalidCodeAddress:
+        System.out.println("Program has failed due to an invalid code address.");
+        break;
+      case failedInvalidInstruction:
+        System.out.println("Program has failed due to an invalid instruction.");
+        break;
+      case failedOverflow:
+        System.out.println("Program has failed due to overflow.");
+        break;
+      case failedZeroDivide:
+        System.out.println("Program has failed due to division by zero.");
+        break;
+      case failedIOError:
+        System.out.println("Program has failed due to an IO error.");
+        break;
+    }
+    if (status != halted)
+      dump();
+  }
+
+  // INTERPRETATION
+
+  static void checkSpace(int spaceNeeded) {
+    // Signals failure if there is not enough space to expand the stack or
+    // heap by spaceNeeded.
+
+    if (HT - ST < spaceNeeded)
+      status = failedDataStoreFull;
+  }
+
+  static boolean isTrue(int datum) {
+    // Tests whether the given datum represents true.
+    return (datum == Machine.trueRep);
+  }
+
+  static boolean equal(int size, int addr1, int addr2) {
+    // Tests whether two multi-word objects are equal, given their common
+    // size and their base addresses.
+
+    boolean eq;
+    int index;
+
+    eq = true;
+    index = 0;
+    while (eq && (index < size))
+      if (data[addr1 + index] == data[addr2 + index])
+        index = index + 1;
+      else
+        eq = false;
+    return eq;
+  }
+
+  static int overflowChecked(long datum) {
+    // Signals failure if the datum is too large to fit into a single word,
+    // otherwise returns the datum as a single word.
+
+    if ((-Machine.maxintRep <= datum) && (datum <= Machine.maxintRep))
+      return (int) datum;
+    else {
+      status = failedOverflow;
+      return 0;
+    }
+  }
+
+  static int toInt(boolean b) {
+    return b ? Machine.trueRep : Machine.falseRep;
+  }
+
+  static int currentChar;
+
+  static int readInt() throws java.io.IOException {
+    int temp = 0;
+    int sign = 1;
+
+    do {
+      currentChar = System.in.read();
+    } while (Character.isWhitespace((char) currentChar));
+
+    if ((currentChar == '-') || (currentChar == '+'))
+      do {
+        sign = (currentChar == '-') ? -1 : 1;
+        currentChar = System.in.read();
+      } while ((currentChar == '-') || currentChar == '+');
+
+    if (Character.isDigit((char) currentChar))
+      do {
+        temp = temp * 10 + (currentChar - '0');
+        currentChar = System.in.read();
+      } while (Character.isDigit((char) currentChar));
+
+    return sign * temp;
+  }
+
+  static void callPrimitive(int primitiveDisplacement) {
+    // Invokes the given primitive routine.
+
+    int addr, size;
+    char ch;
+
+    switch (primitiveDisplacement) {
+      case Machine.idDisplacement:
+        break; // nothing to be done
+      case Machine.notDisplacement:
+        data[ST - 1] = toInt(!isTrue(data[ST - 1]));
+        break;
+      case Machine.andDisplacement:
+        ST = ST - 1;
+        data[ST - 1] = toInt(isTrue(data[ST - 1]) & isTrue(data[ST]));
+        break;
+      case Machine.orDisplacement:
+        ST = ST - 1;
+        data[ST - 1] = toInt(isTrue(data[ST - 1]) | isTrue(data[ST]));
+        break;
+      case Machine.succDisplacement:
+        data[ST - 1] = overflowChecked(data[ST - 1] + 1);
+        break;
+      case Machine.predDisplacement:
+        data[ST - 1] = overflowChecked(data[ST - 1] - 1);
+        break;
+      case Machine.negDisplacement:
+        data[ST - 1] = -data[ST - 1];
+        break;
+      case Machine.addDisplacement:
+        ST = ST - 1;
+        accumulator = data[ST - 1];
+        data[ST - 1] = overflowChecked(accumulator + data[ST]);
+        break;
+      case Machine.subDisplacement:
+        ST = ST - 1;
+        accumulator = data[ST - 1];
+        data[ST - 1] = overflowChecked(accumulator - data[ST]);
+        break;
+      case Machine.multDisplacement:
+        ST = ST - 1;
+        accumulator = data[ST - 1];
+        data[ST - 1] = overflowChecked(accumulator * data[ST]);
+        break;
+      case Machine.divDisplacement:
+        ST = ST - 1;
+        accumulator = data[ST - 1];
+        if (data[ST] != 0)
+          data[ST - 1] = (int) (accumulator / data[ST]);
+        else
+          status = failedZeroDivide;
+        break;
+      case Machine.modDisplacement:
+        ST = ST - 1;
+        accumulator = data[ST - 1];
+        if (data[ST] != 0)
+          data[ST - 1] = (int) (accumulator % data[ST]);
+        else
+          status = failedZeroDivide;
+        break;
+      case Machine.ltDisplacement:
+        ST = ST - 1;
+        data[ST - 1] = toInt(data[ST - 1] < data[ST]);
+        break;
+      case Machine.leDisplacement:
+        ST = ST - 1;
+        data[ST - 1] = toInt(data[ST - 1] <= data[ST]);
+        break;
+      case Machine.geDisplacement:
+        ST = ST - 1;
+        data[ST - 1] = toInt(data[ST - 1] >= data[ST]);
+        break;
+      case Machine.gtDisplacement:
+        ST = ST - 1;
+        data[ST - 1] = toInt(data[ST - 1] > data[ST]);
+        break;
+      case Machine.eqDisplacement:
+        size = data[ST - 1]; // size of each comparand
+        ST = ST - 2 * size;
+        data[ST - 1] = toInt(equal(size, ST - 1, ST - 1 + size));
+        break;
+      case Machine.neDisplacement:
+        size = data[ST - 1]; // size of each comparand
+        ST = ST - 2 * size;
+        data[ST - 1] = toInt(!equal(size, ST - 1, ST - 1 + size));
+        break;
+      case Machine.eolDisplacement:
+        data[ST] = toInt(currentChar == '\n');
+        ST = ST + 1;
+        break;
+      case Machine.eofDisplacement:
+        data[ST] = toInt(currentChar == -1);
+        ST = ST + 1;
+        break;
+      case Machine.getDisplacement:
+        ST = ST - 1;
+        addr = data[ST];
+        try {
+          currentChar = System.in.read();
+        } catch (java.io.IOException s) {
+          status = failedIOError;
+        }
+        data[addr] = (int) currentChar;
+        break;
+      case Machine.putDisplacement:
+        ST = ST - 1;
+        ch = (char) data[ST];
+        System.out.print(ch);
+        break;
+      case Machine.geteolDisplacement:
+        try {
+          while ((currentChar = System.in.read()) != '\n')
+            ;
+        } catch (java.io.IOException s) {
+          status = failedIOError;
+        }
+        break;
+      case Machine.puteolDisplacement:
+        System.out.println("");
+        break;
+      case Machine.getintDisplacement:
+        ST = ST - 1;
+        addr = data[ST];
+        try {
+          accumulator = readInt();
+        } catch (java.io.IOException s) {
+          status = failedIOError;
+        }
+        data[addr] = (int) accumulator;
+        break;
+      case Machine.putintDisplacement:
+        ST = ST - 1;
+        accumulator = data[ST];
+        System.out.print(accumulator);
+        break;
+      case Machine.newDisplacement:
+        size = data[ST - 1];
+        checkSpace(size);
+        HT = HT - size;
+        data[ST - 1] = HT;
+        break;
+      case Machine.disposeDisplacement:
+        ST = ST - 1; // no action taken at present
+        break;
+    }
+  }
+
+  static void interpretProgram() {
+    // Runs the program in code store.
+
+    Instruction currentInstr;
+    int op, r, n, d, addr, index;
+
+    // Initialize registers ...
+    ST = SB;
+    HT = HB;
+    LB = SB;
+    CP = CB;
+    status = running;
+    do {
+      // Fetch instruction ...
+      currentInstr = Machine.code[CP];
+      // Decode instruction ...
+      op = currentInstr.op;
+      r = currentInstr.r;
+      n = currentInstr.n;
+      d = currentInstr.d;
+      // Execute instruction ...
+      switch (op) {
+        case Machine.LOADop:
+          addr = d + content(r);
+          checkSpace(n);
+          for (index = 0; index < n; index++)
+            data[ST + index] = data[addr + index];
+          ST = ST + n;
+          CP = CP + 1;
+          break;
+        case Machine.LOADAop:
+          addr = d + content(r);
+          checkSpace(1);
+          data[ST] = addr;
+          ST = ST + 1;
+          CP = CP + 1;
+          break;
+        case Machine.LOADIop:
+          ST = ST - 1;
+          addr = data[ST];
+          checkSpace(n);
+          for (index = 0; index < n; index++)
+            data[ST + index] = data[addr + index];
+          ST = ST + n;
+          CP = CP + 1;
+          break;
+        case Machine.LOADLop:
+          checkSpace(1);
+          data[ST] = d;
+          ST = ST + 1;
+          CP = CP + 1;
+          break;
+        case Machine.STOREop:
+          addr = d + content(r);
+          ST = ST - n;
+          for (index = 0; index < n; index++)
+            data[addr + index] = data[ST + index];
+          CP = CP + 1;
+          break;
+        case Machine.STOREIop:
+          ST = ST - 1;
+          addr = data[ST];
+          ST = ST - n;
+          for (index = 0; index < n; index++)
+            data[addr + index] = data[ST + index];
+          CP = CP + 1;
+          break;
+        case Machine.CALLop:
+          addr = d + content(r);
+          if (addr >= Machine.PB) {
+            callPrimitive(addr - Machine.PB);
+            CP = CP + 1;
+          } else {
+            checkSpace(3);
+            if ((0 <= n) && (n <= 15))
+              data[ST] = content(n); // static link
+            else
+              status = failedInvalidInstruction;
+            data[ST + 1] = LB; // dynamic link
+            data[ST + 2] = CP + 1; // return address
+            LB = ST;
+            ST = ST + 3;
+            CP = addr;
+          }
+          break;
+        case Machine.CALLIop:
+          ST = ST - 2;
+          addr = data[ST + 1];
+          if (addr >= Machine.PB) {
+            callPrimitive(addr - Machine.PB);
+            CP = CP + 1;
+          } else {
+            // data[ST] = static link already
+            data[ST + 1] = LB; // dynamic link
+            data[ST + 2] = CP + 1; // return address
+            LB = ST;
+            ST = ST + 3;
+            CP = addr;
+          }
+          break;
+        case Machine.RETURNop:
+          addr = LB - d;
+          CP = data[LB + 2];
+          LB = data[LB + 1];
+          ST = ST - n;
+          for (index = 0; index < n; index++)
+            data[addr + index] = data[ST + index];
+          ST = addr + n;
+          break;
+        case Machine.PUSHop:
+          checkSpace(d);
+          ST = ST + d;
+          CP = CP + 1;
+          break;
+        case Machine.POPop:
+          addr = ST - n - d;
+          ST = ST - n;
+          for (index = 0; index < n; index++)
+            data[addr + index] = data[ST + index];
+          ST = addr + n;
+          CP = CP + 1;
+          break;
+        case Machine.JUMPop:
+          CP = d + content(r);
+          break;
+        case Machine.JUMPIop:
+          ST = ST - 1;
+          CP = data[ST];
+          break;
+        case Machine.JUMPIFop:
+          ST = ST - 1;
+          if (data[ST] == n)
+            CP = d + content(r);
+          else
+            CP = CP + 1;
+          break;
+        case Machine.HALTop:
+          status = halted;
+          break;
+      }
+      if ((CP < CB) || (CP >= CT))
+        status = failedInvalidCodeAddress;
+    } while (status == running);
+  }
+
+  // LOADING
+
+  static void loadObjectProgram(String objectName) {
+    // Loads the TAM object program into code store from the named file.
+
+    FileInputStream objectFile = null;
+    DataInputStream objectStream = null;
+
+    int addr;
+    boolean finished = false;
+
+    try {
+      objectFile = new FileInputStream(objectName);
+      objectStream = new DataInputStream(objectFile);
+
+      addr = Machine.CB;
+      while (!finished) {
+        Machine.code[addr] = Instruction.read(objectStream);
+        if (Machine.code[addr] == null)
+          finished = true;
+        else
+          addr = addr + 1;
+      }
+      CT = addr;
+      objectFile.close();
+    } catch (FileNotFoundException s) {
+      CT = CB;
+      System.err.println("Error opening object file: " + s);
+    } catch (IOException s) {
+      CT = CB;
+      System.err.println("Error reading object file: " + s);
+    }
+  }
+
+  // RUNNING
+
+  public static void main(String[] args) {
+    System.out.println("********** TAM Interpreter (Java Version 2.1) **********");
+
+    if (args.length == 1)
+      objectName = args[0];
+    else
+      objectName = "obj.tam";
+
+    loadObjectProgram(objectName);
+    if (CT != CB) {
+      interpretProgram();
+      showStatus();
+    }
+  }
+}

Triangle.AbstractMachine/pom.xml

@@ -0,0 +1,14 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>triangle.tools</groupId>
+    <artifactId>triangle-abstractmachine</artifactId>
+    <version>2.1</version>
+    <packaging>jar</packaging>
+    <parent>
+        <groupId>triangle.tools</groupId>
+        <artifactId>triangle-tools</artifactId>
+        <version>2.1</version>
+        <relativePath>../</relativePath>
+    </parent>
+</project>

Triangle.AbstractMachine/src/main/java/Triangle/AbstractMachine/Instruction.java

@@ -0,0 +1,64 @@
+/*
+ * @(#)Instruction.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractMachine;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.EOFException;
+import java.io.IOException;
+
+public class Instruction {
+
+  public Instruction() {
+    op = 0;
+    r = 0;
+    n = 0;
+    d = 0;
+  }
+
+  // Java has no type synonyms, so the following representations are
+  // assumed:
+  //
+  // type
+  // OpCode = 0..15; {4 bits unsigned}
+  // Length = 0..255; {8 bits unsigned}
+  // Operand = -32767..+32767; {16 bits signed}
+
+  // Represents TAM instructions.
+  public int op; // OpCode
+  public int r; // RegisterNumber
+  public int n; // Length
+  public int d; // Operand
+
+  public void write(DataOutputStream output) throws IOException {
+    output.writeInt(op);
+    output.writeInt(r);
+    output.writeInt(n);
+    output.writeInt(d);
+  }
+
+  public static Instruction read(DataInputStream input) throws IOException {
+    Instruction inst = new Instruction();
+    try {
+      inst.op = input.readInt();
+      inst.r = input.readInt();
+      inst.n = input.readInt();
+      inst.d = input.readInt();
+      return inst;
+    } catch (EOFException s) {
+      return null;
+    }
+  }
+}

Triangle.AbstractMachine/src/main/java/Triangle/AbstractMachine/Machine.java

@@ -0,0 +1,125 @@
+/*
+ * @(#)Machine.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractMachine;
+
+public final class Machine {
+
+  public final static int maxRoutineLevel = 7;
+
+  // WORDS AND ADDRESSES
+
+  // Java has no type synonyms, so the following representations are
+  // assumed:
+  //
+  // type
+  // Word = -32767..+32767; {16 bits signed}
+  // DoubleWord = -2147483648..+2147483647; {32 bits signed}
+  // CodeAddress = 0..+32767; {15 bits unsigned}
+  // DataAddress = 0..+32767; {15 bits unsigned}
+
+  // INSTRUCTIONS
+
+  // Operation codes
+  public final static int LOADop = 0,
+      LOADAop = 1,
+      LOADIop = 2,
+      LOADLop = 3,
+      STOREop = 4,
+      STOREIop = 5,
+      CALLop = 6,
+      CALLIop = 7,
+      RETURNop = 8,
+      PUSHop = 10,
+      POPop = 11,
+      JUMPop = 12,
+      JUMPIop = 13,
+      JUMPIFop = 14,
+      HALTop = 15;
+
+  // CODE STORE
+
+  public static Instruction[] code = new Instruction[1024];
+
+  // CODE STORE REGISTERS
+
+  public final static int CB = 0,
+      PB = 1024, // = upper bound of code array + 1
+      PT = 1052; // = PB + 28
+
+  // REGISTER NUMBERS
+
+  public final static int CBr = 0,
+      CTr = 1,
+      PBr = 2,
+      PTr = 3,
+      SBr = 4,
+      STr = 5,
+      HBr = 6,
+      HTr = 7,
+      LBr = 8,
+      L1r = LBr + 1,
+      L2r = LBr + 2,
+      L3r = LBr + 3,
+      L4r = LBr + 4,
+      L5r = LBr + 5,
+      L6r = LBr + 6,
+      CPr = 15;
+
+  // DATA REPRESENTATION
+
+  public final static int booleanSize = 1,
+      characterSize = 1,
+      integerSize = 1,
+      addressSize = 1,
+      closureSize = 2 * addressSize,
+
+      linkDataSize = 3 * addressSize,
+
+      falseRep = 0,
+      trueRep = 1,
+      maxintRep = 32767;
+
+  // ADDRESSES OF PRIMITIVE ROUTINES
+
+  public final static int idDisplacement = 1,
+      notDisplacement = 2,
+      andDisplacement = 3,
+      orDisplacement = 4,
+      succDisplacement = 5,
+      predDisplacement = 6,
+      negDisplacement = 7,
+      addDisplacement = 8,
+      subDisplacement = 9,
+      multDisplacement = 10,
+      divDisplacement = 11,
+      modDisplacement = 12,
+      ltDisplacement = 13,
+      leDisplacement = 14,
+      geDisplacement = 15,
+      gtDisplacement = 16,
+      eqDisplacement = 17,
+      neDisplacement = 18,
+      eolDisplacement = 19,
+      eofDisplacement = 20,
+      getDisplacement = 21,
+      putDisplacement = 22,
+      geteolDisplacement = 23,
+      puteolDisplacement = 24,
+      getintDisplacement = 25,
+      putintDisplacement = 26,
+      newDisplacement = 27,
+      disposeDisplacement = 28;
+
+}

Triangle.AbstractMachine/target/maven-status/maven-compiler-plugin/compile/default-compile/inputFiles.lst

@@ -0,0 +1,2 @@
+c:\Java\Repos\Triangle-Tools\Triangle.AbstractMachine\src\main\java\Triangle\AbstractMachine\Machine.java
+c:\Java\Repos\Triangle-Tools\Triangle.AbstractMachine\src\main\java\Triangle\AbstractMachine\Instruction.java

Triangle.Compiler/.editorconfig

@@ -0,0 +1,17 @@
+# Editor configuration, see http://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+indent_style = space
+indent_size = 2
+insert_final_newline = true
+trim_trailing_whitespace = true
+max_line_length = 80
+
+[*.sh]
+end_of_line = lf
+
+[*.java]
+indent_size = 4
+max_line_length = 120

Triangle.Compiler/pom.xml

@@ -0,0 +1,20 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>triangle.tools</groupId>
+  <artifactId>triangle-compiler</artifactId>
+  <version>2.1</version>
+  <parent>
+    <groupId>triangle.tools</groupId>
+    <artifactId>triangle-tools</artifactId>
+    <version>2.1</version>
+    <relativePath>../</relativePath>
+  </parent>
+  <dependencies>
+    <dependency>
+      <groupId>triangle.tools</groupId>
+      <artifactId>triangle-abstractmachine</artifactId>
+      <version>2.1</version>
+    </dependency>
+  </dependencies>
+</project>

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/AST.java

@@ -0,0 +1,35 @@
+/*
+ * @(#)AST.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.CodeGenerator.RuntimeEntity;
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class AST {
+
+  public AST(SourcePosition thePosition) {
+    position = thePosition;
+    entity = null;
+  }
+
+  public SourcePosition getPosition() {
+    return position;
+  }
+
+  public abstract Object visit(Visitor v, Object o);
+
+  public SourcePosition position;
+  public RuntimeEntity entity;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ActualParameter.java

@@ -0,0 +1,24 @@
+/*
+ * @(#)ActualParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class ActualParameter extends AST {
+
+  public ActualParameter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ActualParameterSequence.java

@@ -0,0 +1,24 @@
+/*
+ * @(#)ActualParameterSequence.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class ActualParameterSequence extends AST {
+
+  public ActualParameterSequence(SourcePosition thePosition) {
+    super(thePosition);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/AnyTypeDenoter.java

@@ -0,0 +1,32 @@
+/*
+ * @(#)AnyTypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class AnyTypeDenoter extends TypeDenoter {
+
+  public AnyTypeDenoter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitAnyTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    return false;
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ArrayAggregate.java

@@ -0,0 +1,27 @@
+/*
+ * @(#)ArrayAggregate.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class ArrayAggregate extends AST {
+
+  public ArrayAggregate(SourcePosition thePosition) {
+    super(thePosition);
+    elemCount = 0;
+  }
+
+  public int elemCount;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ArrayExpression.java

@@ -0,0 +1,32 @@
+/*
+ * @(#)ArrayExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ArrayExpression extends Expression {
+
+  public ArrayExpression(ArrayAggregate aaAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    AA = aaAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitArrayExpression(this, o);
+  }
+
+  public ArrayAggregate AA;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ArrayTypeDenoter.java

@@ -0,0 +1,44 @@
+/*
+ * @(#)ArrayTypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ArrayTypeDenoter extends TypeDenoter {
+
+  public ArrayTypeDenoter(IntegerLiteral ilAST, TypeDenoter tAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    IL = ilAST;
+    T = tAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitArrayTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    if (obj != null && obj instanceof ErrorTypeDenoter)
+      return true;
+    else if (obj != null && obj instanceof ArrayTypeDenoter)
+      return this.IL.spelling.compareTo(((ArrayTypeDenoter) obj).IL.spelling) == 0 &&
+          this.T.equals(((ArrayTypeDenoter) obj).T);
+    else
+      return false;
+  }
+
+  public IntegerLiteral IL;
+  public TypeDenoter T;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/AssignCommand.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)AssignCommand.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class AssignCommand extends Command {
+
+  public AssignCommand(Vname vAST, Expression eAST, SourcePosition thePosition) {
+    super(thePosition);
+    V = vAST;
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitAssignCommand(this, o);
+  }
+
+  public Vname V;
+  public Expression E;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/BinaryExpression.java

@@ -0,0 +1,35 @@
+/*
+ * @(#)BinaryExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class BinaryExpression extends Expression {
+
+  public BinaryExpression(Expression e1AST, Operator oAST, Expression e2AST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    O = oAST;
+    E1 = e1AST;
+    E2 = e2AST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitBinaryExpression(this, o);
+  }
+
+  public Expression E1, E2;
+  public Operator O;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/BinaryOperatorDeclaration.java

@@ -0,0 +1,37 @@
+/*
+ * @(#)BinaryOperatorDeclaration.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class BinaryOperatorDeclaration extends Declaration {
+
+  public BinaryOperatorDeclaration(Operator oAST, TypeDenoter arg1AST,
+      TypeDenoter arg2AST, TypeDenoter resultAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    O = oAST;
+    ARG1 = arg1AST;
+    ARG2 = arg2AST;
+    RES = resultAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitBinaryOperatorDeclaration(this, o);
+  }
+
+  public Operator O;
+  public TypeDenoter ARG1, ARG2, RES;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/BoolTypeDenoter.java

@@ -0,0 +1,35 @@
+/*
+ * @(#)BoolTypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class BoolTypeDenoter extends TypeDenoter {
+
+  public BoolTypeDenoter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitBoolTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    if ((obj != null) && (obj instanceof ErrorTypeDenoter))
+      return true;
+    else
+      return ((obj != null) && (obj instanceof BoolTypeDenoter));
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/CallCommand.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)CallCommand.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class CallCommand extends Command {
+
+  public CallCommand(Identifier iAST, ActualParameterSequence apsAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    APS = apsAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitCallCommand(this, o);
+  }
+
+  public Identifier I;
+  public ActualParameterSequence APS;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/CallExpression.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)CallExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class CallExpression extends Expression {
+
+  public CallExpression(Identifier iAST, ActualParameterSequence apsAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    APS = apsAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitCallExpression(this, o);
+  }
+
+  public Identifier I;
+  public ActualParameterSequence APS;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/CharTypeDenoter.java

@@ -0,0 +1,35 @@
+/*
+ * @(#)CharTypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class CharTypeDenoter extends TypeDenoter {
+
+  public CharTypeDenoter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitCharTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    if (obj != null && obj instanceof ErrorTypeDenoter)
+      return true;
+    else
+      return (obj != null && obj instanceof CharTypeDenoter);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/CharacterExpression.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)CharacterExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class CharacterExpression extends Expression {
+
+  public CharacterExpression(CharacterLiteral clAST, SourcePosition thePosition) {
+    super(thePosition);
+    CL = clAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitCharacterExpression(this, o);
+  }
+
+  public CharacterLiteral CL;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/CharacterLiteral.java

@@ -0,0 +1,29 @@
+/*
+ * @(#)CharacterLiteral.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class CharacterLiteral extends Terminal {
+
+  public CharacterLiteral(String theSpelling, SourcePosition thePosition) {
+    super(theSpelling, thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitCharacterLiteral(this, o);
+  }
+
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Command.java

@@ -0,0 +1,24 @@
+/*
+ * @(#)Command.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Command extends AST {
+
+  public Command(SourcePosition thePosition) {
+    super(thePosition);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ConstActualParameter.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)ConstActualParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ConstActualParameter extends ActualParameter {
+
+  public ConstActualParameter(Expression eAST, SourcePosition thePosition) {
+    super(thePosition);
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitConstActualParameter(this, o);
+  }
+
+  public Expression E;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ConstDeclaration.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)ConstDeclaration.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ConstDeclaration extends Declaration {
+
+  public ConstDeclaration(Identifier iAST, Expression eAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitConstDeclaration(this, o);
+  }
+
+  public Identifier I;
+  public Expression E;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ConstFormalParameter.java

@@ -0,0 +1,42 @@
+/*
+ * @(#)ConstFormalParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ConstFormalParameter extends FormalParameter {
+
+  public ConstFormalParameter(Identifier iAST, TypeDenoter tAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    T = tAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitConstFormalParameter(this, o);
+  }
+
+  public Identifier I;
+  public TypeDenoter T;
+
+  public boolean equals(Object fpAST) {
+    if (fpAST instanceof ConstFormalParameter) {
+      ConstFormalParameter cfpAST = (ConstFormalParameter) fpAST;
+      return T.equals(cfpAST.T);
+    } else
+      return false;
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Declaration.java

@@ -0,0 +1,27 @@
+/*
+ * @(#)Declaration.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Declaration extends AST {
+
+  public Declaration(SourcePosition thePosition) {
+    super(thePosition);
+    duplicated = false;
+  }
+
+  public boolean duplicated;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/DotVname.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)DotVname.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class DotVname extends Vname {
+
+  public DotVname(Vname vAST, Identifier iAST, SourcePosition thePosition) {
+    super(thePosition);
+    V = vAST;
+    I = iAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitDotVname(this, o);
+  }
+
+  public Identifier I;
+  public Vname V;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/EmptyActualParameterSequence.java

@@ -0,0 +1,28 @@
+/*
+ * @(#)EmptyActualParameterSequence.java        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class EmptyActualParameterSequence extends ActualParameterSequence {
+
+  public EmptyActualParameterSequence(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitEmptyActualParameterSequence(this, o);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/EmptyCommand.java

@@ -0,0 +1,28 @@
+/*
+ * @(#)EmptyCommand.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class EmptyCommand extends Command {
+
+  public EmptyCommand(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitEmptyCommand(this, o);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/EmptyExpression.java

@@ -0,0 +1,28 @@
+/*
+ * @(#)EmptyExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class EmptyExpression extends Expression {
+
+  public EmptyExpression(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitEmptyExpression(this, o);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/EmptyFormalParameterSequence.java

@@ -0,0 +1,32 @@
+/*
+ * @(#)EmptyFormalParameterSequence.java        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class EmptyFormalParameterSequence extends FormalParameterSequence {
+
+  public EmptyFormalParameterSequence(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitEmptyFormalParameterSequence(this, o);
+  }
+
+  public boolean equals(Object fpsAST) {
+    return (fpsAST instanceof EmptyFormalParameterSequence);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ErrorTypeDenoter.java

@@ -0,0 +1,32 @@
+/*
+ * @(#)ErrorTypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ErrorTypeDenoter extends TypeDenoter {
+
+  public ErrorTypeDenoter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitErrorTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    return true;
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Expression.java

@@ -0,0 +1,27 @@
+/*
+ * @(#)Expression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Expression extends AST {
+
+  public Expression(SourcePosition thePosition) {
+    super(thePosition);
+    type = null;
+  }
+
+  public TypeDenoter type;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/FieldTypeDenoter.java

@@ -0,0 +1,26 @@
+/*
+ * @(#)FieldTypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class FieldTypeDenoter extends TypeDenoter {
+
+  public FieldTypeDenoter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public abstract boolean equals(Object obj);
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/FormalParameter.java

@@ -0,0 +1,27 @@
+/*
+ * @(#)FormalParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class FormalParameter extends Declaration {
+
+  public FormalParameter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public abstract boolean equals(Object fpAST);
+
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/FormalParameterSequence.java

@@ -0,0 +1,26 @@
+/*
+ * @(#)FormalParameterSequence.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class FormalParameterSequence extends AST {
+
+  public FormalParameterSequence(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public abstract boolean equals(Object fpsAST);
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/FuncActualParameter.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)FuncActualParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class FuncActualParameter extends ActualParameter {
+
+  public FuncActualParameter(Identifier iAST, SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitFuncActualParameter(this, o);
+  }
+
+  public Identifier I;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/FuncDeclaration.java

@@ -0,0 +1,39 @@
+/*
+ * @(#)FuncDeclaration.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class FuncDeclaration extends Declaration {
+
+  public FuncDeclaration(Identifier iAST, FormalParameterSequence fpsAST,
+      TypeDenoter tAST, Expression eAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    FPS = fpsAST;
+    T = tAST;
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitFuncDeclaration(this, o);
+  }
+
+  public Identifier I;
+  public FormalParameterSequence FPS;
+  public TypeDenoter T;
+  public Expression E;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/FuncFormalParameter.java

@@ -0,0 +1,44 @@
+/*
+ * @(#)FuncFormalParameter.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class FuncFormalParameter extends FormalParameter {
+
+  public FuncFormalParameter(Identifier iAST, FormalParameterSequence fpsAST,
+      TypeDenoter tAST, SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    FPS = fpsAST;
+    T = tAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitFuncFormalParameter(this, o);
+  }
+
+  public boolean equals(Object fpAST) {
+    if (fpAST instanceof FuncFormalParameter) {
+      FuncFormalParameter ffpAST = (FuncFormalParameter) fpAST;
+      return FPS.equals(ffpAST.FPS) && T.equals(ffpAST.T);
+    } else
+      return false;
+  }
+
+  public Identifier I;
+  public FormalParameterSequence FPS;
+  public TypeDenoter T;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Identifier.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)Identifier.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class Identifier extends Terminal {
+
+  public Identifier(String theSpelling, SourcePosition thePosition) {
+    super(theSpelling, thePosition);
+    type = null;
+    decl = null;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitIdentifier(this, o);
+  }
+
+  public TypeDenoter type;
+  public AST decl; // Either a Declaration or a FieldTypeDenoter
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/IfCommand.java

@@ -0,0 +1,35 @@
+/*
+ * @(#)IfCommand.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class IfCommand extends Command {
+
+  public IfCommand(Expression eAST, Command c1AST, Command c2AST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    E = eAST;
+    C1 = c1AST;
+    C2 = c2AST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitIfCommand(this, o);
+  }
+
+  public Expression E;
+  public Command C1, C2;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/IfExpression.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)IfExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class IfExpression extends Expression {
+
+  public IfExpression(Expression e1AST, Expression e2AST, Expression e3AST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    E1 = e1AST;
+    E2 = e2AST;
+    E3 = e3AST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitIfExpression(this, o);
+  }
+
+  public Expression E1, E2, E3;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/IntTypeDenoter.java

@@ -0,0 +1,35 @@
+/*
+ * @(#)IntTypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class IntTypeDenoter extends TypeDenoter {
+
+  public IntTypeDenoter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitIntTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    if (obj != null && obj instanceof ErrorTypeDenoter)
+      return true;
+    else
+      return (obj != null && obj instanceof IntTypeDenoter);
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/IntegerExpression.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)IntegerExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class IntegerExpression extends Expression {
+
+  public IntegerExpression(IntegerLiteral ilAST, SourcePosition thePosition) {
+    super(thePosition);
+    IL = ilAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitIntegerExpression(this, o);
+  }
+
+  public IntegerLiteral IL;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/IntegerLiteral.java

@@ -0,0 +1,29 @@
+/*
+ * @(#)IntegerLiteral.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class IntegerLiteral extends Terminal {
+
+  public IntegerLiteral(String theSpelling, SourcePosition thePosition) {
+    super(theSpelling, thePosition);
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitIntegerLiteral(this, o);
+  }
+
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/LetCommand.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)LetCommand.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class LetCommand extends Command {
+
+  public LetCommand(Declaration dAST, Command cAST, SourcePosition thePosition) {
+    super(thePosition);
+    D = dAST;
+    C = cAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitLetCommand(this, o);
+  }
+
+  public Declaration D;
+  public Command C;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/LetExpression.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)LetExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class LetExpression extends Expression {
+
+  public LetExpression(Declaration dAST, Expression eAST, SourcePosition thePosition) {
+    super(thePosition);
+    D = dAST;
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitLetExpression(this, o);
+  }
+
+  public Declaration D;
+  public Expression E;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/MultipleActualParameterSequence.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)MultipleActualParameterSequence.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class MultipleActualParameterSequence extends ActualParameterSequence {
+
+  public MultipleActualParameterSequence(ActualParameter apAST, ActualParameterSequence apsAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    AP = apAST;
+    APS = apsAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitMultipleActualParameterSequence(this, o);
+  }
+
+  public ActualParameter AP;
+  public ActualParameterSequence APS;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/MultipleArrayAggregate.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)MultipleArrayAggregate.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class MultipleArrayAggregate extends ArrayAggregate {
+
+  public MultipleArrayAggregate(Expression eAST, ArrayAggregate aaAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    E = eAST;
+    AA = aaAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitMultipleArrayAggregate(this, o);
+  }
+
+  public Expression E;
+  public ArrayAggregate AA;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/MultipleFieldTypeDenoter.java

@@ -0,0 +1,46 @@
+/*
+ * @(#)MultipleFieldTypeDenoter.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class MultipleFieldTypeDenoter extends FieldTypeDenoter {
+
+  public MultipleFieldTypeDenoter(Identifier iAST, TypeDenoter tAST, FieldTypeDenoter ftAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    T = tAST;
+    FT = ftAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitMultipleFieldTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    if (obj != null && obj instanceof MultipleFieldTypeDenoter) {
+      MultipleFieldTypeDenoter ft = (MultipleFieldTypeDenoter) obj;
+      return (this.I.spelling.compareTo(ft.I.spelling) == 0) &&
+          this.T.equals(ft.T) &&
+          this.FT.equals(ft.FT);
+    } else
+      return false;
+  }
+
+  public Identifier I;
+  public TypeDenoter T;
+  public FieldTypeDenoter FT;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/MultipleFormalParameterSequence.java

@@ -0,0 +1,42 @@
+/*
+ * @(#)MultipleFormalParameterSequence.java        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class MultipleFormalParameterSequence extends FormalParameterSequence {
+
+  public MultipleFormalParameterSequence(FormalParameter fpAST, FormalParameterSequence fpsAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    FP = fpAST;
+    FPS = fpsAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitMultipleFormalParameterSequence(this, o);
+  }
+
+  public boolean equals(Object fpsAST) {
+    if (fpsAST instanceof MultipleFormalParameterSequence) {
+      MultipleFormalParameterSequence mfpsAST = (MultipleFormalParameterSequence) fpsAST;
+      return FP.equals(mfpsAST.FP) && FPS.equals(mfpsAST.FPS);
+    } else
+      return false;
+  }
+
+  public FormalParameter FP;
+  public FormalParameterSequence FPS;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/MultipleRecordAggregate.java

@@ -0,0 +1,36 @@
+/*
+ * @(#)MultipleRecordAggregate.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class MultipleRecordAggregate extends RecordAggregate {
+
+  public MultipleRecordAggregate(Identifier iAST, Expression eAST, RecordAggregate raAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    E = eAST;
+    RA = raAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitMultipleRecordAggregate(this, o);
+  }
+
+  public Identifier I;
+  public Expression E;
+  public RecordAggregate RA;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Operator.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)Operator.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class Operator extends Terminal {
+
+  public Operator(String theSpelling, SourcePosition thePosition) {
+    super(theSpelling, thePosition);
+    decl = null;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitOperator(this, o);
+  }
+
+  public Declaration decl;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ProcActualParameter.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)ProcActualParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ProcActualParameter extends ActualParameter {
+
+  public ProcActualParameter(Identifier iAST, SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitProcActualParameter(this, o);
+  }
+
+  public Identifier I;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ProcDeclaration.java

@@ -0,0 +1,36 @@
+/*
+ * @(#)ProcDeclaration.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ProcDeclaration extends Declaration {
+
+  public ProcDeclaration(Identifier iAST, FormalParameterSequence fpsAST,
+      Command cAST, SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    FPS = fpsAST;
+    C = cAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitProcDeclaration(this, o);
+  }
+
+  public Identifier I;
+  public FormalParameterSequence FPS;
+  public Command C;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/ProcFormalParameter.java

@@ -0,0 +1,42 @@
+/*
+ * @(#)ProcFormalParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class ProcFormalParameter extends FormalParameter {
+
+  public ProcFormalParameter(Identifier iAST, FormalParameterSequence fpsAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    FPS = fpsAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitProcFormalParameter(this, o);
+  }
+
+  public Identifier I;
+  public FormalParameterSequence FPS;
+
+  public boolean equals(Object fpAST) {
+    if (fpAST instanceof ProcFormalParameter) {
+      ProcFormalParameter pfpAST = (ProcFormalParameter) fpAST;
+      return FPS.equals(pfpAST.FPS);
+    } else
+      return false;
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Program.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)Program.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class Program extends AST {
+
+  public Program(Command cAST, SourcePosition thePosition) {
+    super(thePosition);
+    C = cAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitProgram(this, o);
+  }
+
+  public Command C;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/RecordAggregate.java

@@ -0,0 +1,27 @@
+/*
+ * @(#)RecordAggregate.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class RecordAggregate extends AST {
+
+  public RecordAggregate(SourcePosition thePosition) {
+    super(thePosition);
+    type = null;
+  }
+
+  public FieldTypeDenoter type;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/RecordExpression.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)RecordExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class RecordExpression extends Expression {
+
+  public RecordExpression(RecordAggregate raAST, SourcePosition thePosition) {
+    super(thePosition);
+    RA = raAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitRecordExpression(this, o);
+  }
+
+  public RecordAggregate RA;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/RecordTypeDenoter.java

@@ -0,0 +1,40 @@
+/*
+ * @(#)RecordTypeDenoter.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class RecordTypeDenoter extends TypeDenoter {
+
+  public RecordTypeDenoter(FieldTypeDenoter ftAST, SourcePosition thePosition) {
+    super(thePosition);
+    FT = ftAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitRecordTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    if (obj != null && obj instanceof ErrorTypeDenoter)
+      return true;
+    else if (obj != null && obj instanceof RecordTypeDenoter)
+      return this.FT.equals(((RecordTypeDenoter) obj).FT);
+    else
+      return false;
+  }
+
+  public FieldTypeDenoter FT;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SequentialCommand.java

@@ -0,0 +1,32 @@
+/*
+ * @(#)SequentialCommand.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SequentialCommand extends Command {
+
+  public SequentialCommand(Command c1AST, Command c2AST, SourcePosition thePosition) {
+    super(thePosition);
+    C1 = c1AST;
+    C2 = c2AST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSequentialCommand(this, o);
+  }
+
+  public Command C1, C2;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SequentialDeclaration.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)SequentialDeclaration.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SequentialDeclaration extends Declaration {
+
+  public SequentialDeclaration(Declaration d1AST, Declaration d2AST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    D1 = d1AST;
+    D2 = d2AST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSequentialDeclaration(this, o);
+  }
+
+  public Declaration D1, D2;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SimpleTypeDenoter.java

@@ -0,0 +1,35 @@
+/*
+ * @(#)SimpleTypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SimpleTypeDenoter extends TypeDenoter {
+
+  public SimpleTypeDenoter(Identifier iAST, SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSimpleTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    return false; // should not happen
+  }
+
+  public Identifier I;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SimpleVname.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)SimpleVname.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SimpleVname extends Vname {
+
+  public SimpleVname(Identifier iAST, SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSimpleVname(this, o);
+  }
+
+  public Identifier I;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SingleActualParameterSequence.java

@@ -0,0 +1,32 @@
+/*
+ * @(#)SingleActualParameterSequence.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SingleActualParameterSequence extends ActualParameterSequence {
+
+  public SingleActualParameterSequence(ActualParameter apAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    AP = apAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSingleActualParameterSequence(this, o);
+  }
+
+  public ActualParameter AP;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SingleArrayAggregate.java

@@ -0,0 +1,32 @@
+/*
+ * @(#)SingleArrayAggregate.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SingleArrayAggregate extends ArrayAggregate {
+
+  public SingleArrayAggregate(Expression eAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSingleArrayAggregate(this, o);
+  }
+
+  public Expression E;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SingleFieldTypeDenoter.java

@@ -0,0 +1,43 @@
+/*
+ * @(#)SingleFieldTypeDenoter.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SingleFieldTypeDenoter extends FieldTypeDenoter {
+
+  public SingleFieldTypeDenoter(Identifier iAST, TypeDenoter tAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    T = tAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSingleFieldTypeDenoter(this, o);
+  }
+
+  public boolean equals(Object obj) {
+    if (obj != null && obj instanceof SingleFieldTypeDenoter) {
+      SingleFieldTypeDenoter ft = (SingleFieldTypeDenoter) obj;
+      return (this.I.spelling.compareTo(ft.I.spelling) == 0) &&
+          this.T.equals(ft.T);
+    } else
+      return false;
+  }
+
+  public Identifier I;
+  public TypeDenoter T;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SingleFormalParameterSequence.java

@@ -0,0 +1,40 @@
+/*
+ * @(#)SingleFormalParameterSequence.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SingleFormalParameterSequence extends FormalParameterSequence {
+
+  public SingleFormalParameterSequence(FormalParameter fpAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    FP = fpAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSingleFormalParameterSequence(this, o);
+  }
+
+  public boolean equals(Object fpsAST) {
+    if (fpsAST instanceof SingleFormalParameterSequence) {
+      SingleFormalParameterSequence sfpsAST = (SingleFormalParameterSequence) fpsAST;
+      return FP.equals(sfpsAST.FP);
+    } else
+      return false;
+  }
+
+  public FormalParameter FP;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SingleRecordAggregate.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)SingleRecordAggregate.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SingleRecordAggregate extends RecordAggregate {
+
+  public SingleRecordAggregate(Identifier iAST, Expression eAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSingleRecordAggregate(this, o);
+  }
+
+  public Identifier I;
+  public Expression E;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/SubscriptVname.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)SubscriptVname.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class SubscriptVname extends Vname {
+
+  public SubscriptVname(Vname vAST, Expression eAST, SourcePosition thePosition) {
+    super(thePosition);
+    V = vAST;
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitSubscriptVname(this, o);
+  }
+
+  public Expression E;
+  public Vname V;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Terminal.java

@@ -0,0 +1,27 @@
+/*
+ * @(#)Terminal.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+abstract public class Terminal extends AST {
+
+  public Terminal(String theSpelling, SourcePosition thePosition) {
+    super(thePosition);
+    spelling = theSpelling;
+  }
+
+  public String spelling;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/TypeDeclaration.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)TypeDeclaration.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class TypeDeclaration extends Declaration {
+
+  public TypeDeclaration(Identifier iAST, TypeDenoter tAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    T = tAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitTypeDeclaration(this, o);
+  }
+
+  public Identifier I;
+  public TypeDenoter T;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/TypeDenoter.java

@@ -0,0 +1,27 @@
+/*
+ * @(#)TypeDenoter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class TypeDenoter extends AST {
+
+  public TypeDenoter(SourcePosition thePosition) {
+    super(thePosition);
+  }
+
+  public abstract boolean equals(Object obj);
+
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/UnaryExpression.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)UnaryExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class UnaryExpression extends Expression {
+
+  public UnaryExpression(Operator oAST, Expression eAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    O = oAST;
+    E = eAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitUnaryExpression(this, o);
+  }
+
+  public Expression E;
+  public Operator O;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/UnaryOperatorDeclaration.java

@@ -0,0 +1,35 @@
+/*
+ * @(#)UnaryOperatorDeclaration.java                2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class UnaryOperatorDeclaration extends Declaration {
+
+  public UnaryOperatorDeclaration(Operator oAST, TypeDenoter argAST,
+      TypeDenoter resultAST, SourcePosition thePosition) {
+    super(thePosition);
+    O = oAST;
+    ARG = argAST;
+    RES = resultAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitUnaryOperatorDeclaration(this, o);
+  }
+
+  public Operator O;
+  public TypeDenoter ARG, RES;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/VarActualParameter.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)VarActualParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class VarActualParameter extends ActualParameter {
+
+  public VarActualParameter(Vname vAST, SourcePosition thePosition) {
+    super(thePosition);
+    V = vAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitVarActualParameter(this, o);
+  }
+
+  public Vname V;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/VarDeclaration.java

@@ -0,0 +1,34 @@
+/*
+ * @(#)VarDeclaration.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class VarDeclaration extends Declaration {
+
+  public VarDeclaration(Identifier iAST, TypeDenoter tAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    T = tAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitVarDeclaration(this, o);
+  }
+
+  public Identifier I;
+  public TypeDenoter T;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/VarFormalParameter.java

@@ -0,0 +1,42 @@
+/*
+ * @(#)ValFormalParameter.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class VarFormalParameter extends FormalParameter {
+
+  public VarFormalParameter(Identifier iAST, TypeDenoter tAST,
+      SourcePosition thePosition) {
+    super(thePosition);
+    I = iAST;
+    T = tAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitVarFormalParameter(this, o);
+  }
+
+  public Identifier I;
+  public TypeDenoter T;
+
+  public boolean equals(Object fpAST) {
+    if (fpAST instanceof VarFormalParameter) {
+      VarFormalParameter vfpAST = (VarFormalParameter) fpAST;
+      return T.equals(vfpAST.T);
+    } else
+      return false;
+  }
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Visitor.java

@@ -0,0 +1,154 @@
+/*
+ * @(#)Visitor.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+public interface Visitor {
+
+  // Commands
+  public abstract Object visitAssignCommand(AssignCommand ast, Object o);
+
+  public abstract Object visitCallCommand(CallCommand ast, Object o);
+
+  public abstract Object visitEmptyCommand(EmptyCommand ast, Object o);
+
+  public abstract Object visitIfCommand(IfCommand ast, Object o);
+
+  public abstract Object visitLetCommand(LetCommand ast, Object o);
+
+  public abstract Object visitSequentialCommand(SequentialCommand ast, Object o);
+
+  public abstract Object visitWhileCommand(WhileCommand ast, Object o);
+
+  // Expressions
+  public abstract Object visitArrayExpression(ArrayExpression ast, Object o);
+
+  public abstract Object visitBinaryExpression(BinaryExpression ast, Object o);
+
+  public abstract Object visitCallExpression(CallExpression ast, Object o);
+
+  public abstract Object visitCharacterExpression(CharacterExpression ast, Object o);
+
+  public abstract Object visitEmptyExpression(EmptyExpression ast, Object o);
+
+  public abstract Object visitIfExpression(IfExpression ast, Object o);
+
+  public abstract Object visitIntegerExpression(IntegerExpression ast, Object o);
+
+  public abstract Object visitLetExpression(LetExpression ast, Object o);
+
+  public abstract Object visitRecordExpression(RecordExpression ast, Object o);
+
+  public abstract Object visitUnaryExpression(UnaryExpression ast, Object o);
+
+  public abstract Object visitVnameExpression(VnameExpression ast, Object o);
+
+  // Declarations
+  public abstract Object visitBinaryOperatorDeclaration(BinaryOperatorDeclaration ast, Object o);
+
+  public abstract Object visitConstDeclaration(ConstDeclaration ast, Object o);
+
+  public abstract Object visitFuncDeclaration(FuncDeclaration ast, Object o);
+
+  public abstract Object visitProcDeclaration(ProcDeclaration ast, Object o);
+
+  public abstract Object visitSequentialDeclaration(SequentialDeclaration ast, Object o);
+
+  public abstract Object visitTypeDeclaration(TypeDeclaration ast, Object o);
+
+  public abstract Object visitUnaryOperatorDeclaration(UnaryOperatorDeclaration ast, Object o);
+
+  public abstract Object visitVarDeclaration(VarDeclaration ast, Object o);
+
+  // Array Aggregates
+  public abstract Object visitMultipleArrayAggregate(MultipleArrayAggregate ast, Object o);
+
+  public abstract Object visitSingleArrayAggregate(SingleArrayAggregate ast, Object o);
+
+  // Record Aggregates
+  public abstract Object visitMultipleRecordAggregate(MultipleRecordAggregate ast, Object o);
+
+  public abstract Object visitSingleRecordAggregate(SingleRecordAggregate ast, Object o);
+
+  // Formal Parameters
+  public abstract Object visitConstFormalParameter(ConstFormalParameter ast, Object o);
+
+  public abstract Object visitFuncFormalParameter(FuncFormalParameter ast, Object o);
+
+  public abstract Object visitProcFormalParameter(ProcFormalParameter ast, Object o);
+
+  public abstract Object visitVarFormalParameter(VarFormalParameter ast, Object o);
+
+  public abstract Object visitEmptyFormalParameterSequence(EmptyFormalParameterSequence ast, Object o);
+
+  public abstract Object visitMultipleFormalParameterSequence(MultipleFormalParameterSequence ast, Object o);
+
+  public abstract Object visitSingleFormalParameterSequence(SingleFormalParameterSequence ast, Object o);
+
+  // Actual Parameters
+  public abstract Object visitConstActualParameter(ConstActualParameter ast, Object o);
+
+  public abstract Object visitFuncActualParameter(FuncActualParameter ast, Object o);
+
+  public abstract Object visitProcActualParameter(ProcActualParameter ast, Object o);
+
+  public abstract Object visitVarActualParameter(VarActualParameter ast, Object o);
+
+  public abstract Object visitEmptyActualParameterSequence(EmptyActualParameterSequence ast, Object o);
+
+  public abstract Object visitMultipleActualParameterSequence(MultipleActualParameterSequence ast, Object o);
+
+  public abstract Object visitSingleActualParameterSequence(SingleActualParameterSequence ast, Object o);
+
+  // Type Denoters
+  public abstract Object visitAnyTypeDenoter(AnyTypeDenoter ast, Object o);
+
+  public abstract Object visitArrayTypeDenoter(ArrayTypeDenoter ast, Object o);
+
+  public abstract Object visitBoolTypeDenoter(BoolTypeDenoter ast, Object o);
+
+  public abstract Object visitCharTypeDenoter(CharTypeDenoter ast, Object o);
+
+  public abstract Object visitErrorTypeDenoter(ErrorTypeDenoter ast, Object o);
+
+  public abstract Object visitSimpleTypeDenoter(SimpleTypeDenoter ast, Object o);
+
+  public abstract Object visitIntTypeDenoter(IntTypeDenoter ast, Object o);
+
+  public abstract Object visitRecordTypeDenoter(RecordTypeDenoter ast, Object o);
+
+  public abstract Object visitMultipleFieldTypeDenoter(MultipleFieldTypeDenoter ast, Object o);
+
+  public abstract Object visitSingleFieldTypeDenoter(SingleFieldTypeDenoter ast, Object o);
+
+  // Literals, Identifiers and Operators
+  public abstract Object visitCharacterLiteral(CharacterLiteral ast, Object o);
+
+  public abstract Object visitIdentifier(Identifier ast, Object o);
+
+  public abstract Object visitIntegerLiteral(IntegerLiteral ast, Object o);
+
+  public abstract Object visitOperator(Operator ast, Object o);
+
+  // Value-or-variable names
+  public abstract Object visitDotVname(DotVname ast, Object o);
+
+  public abstract Object visitSimpleVname(SimpleVname ast, Object o);
+
+  public abstract Object visitSubscriptVname(SubscriptVname ast, Object o);
+
+  // Programs
+  public abstract Object visitProgram(Program ast, Object o);
+
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/Vname.java

@@ -0,0 +1,30 @@
+/*
+ * @(#)Vname.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public abstract class Vname extends AST {
+
+  public Vname(SourcePosition thePosition) {
+    super(thePosition);
+    variable = false;
+    type = null;
+  }
+
+  public boolean variable, indexed;
+  public int offset;
+  public TypeDenoter type;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/VnameExpression.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)VnameExpression.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class VnameExpression extends Expression {
+
+  public VnameExpression(Vname vAST, SourcePosition thePosition) {
+    super(thePosition);
+    V = vAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitVnameExpression(this, o);
+  }
+
+  public Vname V;
+}

Triangle.Compiler/src/main/java/Triangle/AbstractSyntaxTrees/WhileCommand.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)WhileCommand.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.AbstractSyntaxTrees;
+
+import Triangle.SyntacticAnalyzer.SourcePosition;
+
+public class WhileCommand extends Command {
+
+  public WhileCommand(Expression eAST, Command cAST, SourcePosition thePosition) {
+    super(thePosition);
+    E = eAST;
+    C = cAST;
+  }
+
+  public Object visit(Visitor v, Object o) {
+    return v.visitWhileCommand(this, o);
+  }
+
+  public Expression E;
+  public Command C;
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/Encoder.java

@@ -0,0 +1,983 @@
+/*
+ * @(#)Encoder.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+import java.io.DataOutputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+import Triangle.ErrorReporter;
+import Triangle.StdEnvironment;
+import Triangle.AbstractMachine.Instruction;
+import Triangle.AbstractMachine.Machine;
+import Triangle.AbstractSyntaxTrees.AST;
+import Triangle.AbstractSyntaxTrees.AnyTypeDenoter;
+import Triangle.AbstractSyntaxTrees.ArrayExpression;
+import Triangle.AbstractSyntaxTrees.ArrayTypeDenoter;
+import Triangle.AbstractSyntaxTrees.AssignCommand;
+import Triangle.AbstractSyntaxTrees.BinaryExpression;
+import Triangle.AbstractSyntaxTrees.BinaryOperatorDeclaration;
+import Triangle.AbstractSyntaxTrees.BoolTypeDenoter;
+import Triangle.AbstractSyntaxTrees.CallCommand;
+import Triangle.AbstractSyntaxTrees.CallExpression;
+import Triangle.AbstractSyntaxTrees.CharTypeDenoter;
+import Triangle.AbstractSyntaxTrees.CharacterExpression;
+import Triangle.AbstractSyntaxTrees.CharacterLiteral;
+import Triangle.AbstractSyntaxTrees.ConstActualParameter;
+import Triangle.AbstractSyntaxTrees.ConstDeclaration;
+import Triangle.AbstractSyntaxTrees.ConstFormalParameter;
+import Triangle.AbstractSyntaxTrees.Declaration;
+import Triangle.AbstractSyntaxTrees.DotVname;
+import Triangle.AbstractSyntaxTrees.EmptyActualParameterSequence;
+import Triangle.AbstractSyntaxTrees.EmptyCommand;
+import Triangle.AbstractSyntaxTrees.EmptyExpression;
+import Triangle.AbstractSyntaxTrees.EmptyFormalParameterSequence;
+import Triangle.AbstractSyntaxTrees.ErrorTypeDenoter;
+import Triangle.AbstractSyntaxTrees.FuncActualParameter;
+import Triangle.AbstractSyntaxTrees.FuncDeclaration;
+import Triangle.AbstractSyntaxTrees.FuncFormalParameter;
+import Triangle.AbstractSyntaxTrees.Identifier;
+import Triangle.AbstractSyntaxTrees.IfCommand;
+import Triangle.AbstractSyntaxTrees.IfExpression;
+import Triangle.AbstractSyntaxTrees.IntTypeDenoter;
+import Triangle.AbstractSyntaxTrees.IntegerExpression;
+import Triangle.AbstractSyntaxTrees.IntegerLiteral;
+import Triangle.AbstractSyntaxTrees.LetCommand;
+import Triangle.AbstractSyntaxTrees.LetExpression;
+import Triangle.AbstractSyntaxTrees.MultipleActualParameterSequence;
+import Triangle.AbstractSyntaxTrees.MultipleArrayAggregate;
+import Triangle.AbstractSyntaxTrees.MultipleFieldTypeDenoter;
+import Triangle.AbstractSyntaxTrees.MultipleFormalParameterSequence;
+import Triangle.AbstractSyntaxTrees.MultipleRecordAggregate;
+import Triangle.AbstractSyntaxTrees.Operator;
+import Triangle.AbstractSyntaxTrees.ProcActualParameter;
+import Triangle.AbstractSyntaxTrees.ProcDeclaration;
+import Triangle.AbstractSyntaxTrees.ProcFormalParameter;
+import Triangle.AbstractSyntaxTrees.Program;
+import Triangle.AbstractSyntaxTrees.RecordExpression;
+import Triangle.AbstractSyntaxTrees.RecordTypeDenoter;
+import Triangle.AbstractSyntaxTrees.SequentialCommand;
+import Triangle.AbstractSyntaxTrees.SequentialDeclaration;
+import Triangle.AbstractSyntaxTrees.SimpleTypeDenoter;
+import Triangle.AbstractSyntaxTrees.SimpleVname;
+import Triangle.AbstractSyntaxTrees.SingleActualParameterSequence;
+import Triangle.AbstractSyntaxTrees.SingleArrayAggregate;
+import Triangle.AbstractSyntaxTrees.SingleFieldTypeDenoter;
+import Triangle.AbstractSyntaxTrees.SingleFormalParameterSequence;
+import Triangle.AbstractSyntaxTrees.SingleRecordAggregate;
+import Triangle.AbstractSyntaxTrees.SubscriptVname;
+import Triangle.AbstractSyntaxTrees.TypeDeclaration;
+import Triangle.AbstractSyntaxTrees.UnaryExpression;
+import Triangle.AbstractSyntaxTrees.UnaryOperatorDeclaration;
+import Triangle.AbstractSyntaxTrees.VarActualParameter;
+import Triangle.AbstractSyntaxTrees.VarDeclaration;
+import Triangle.AbstractSyntaxTrees.VarFormalParameter;
+import Triangle.AbstractSyntaxTrees.Visitor;
+import Triangle.AbstractSyntaxTrees.Vname;
+import Triangle.AbstractSyntaxTrees.VnameExpression;
+import Triangle.AbstractSyntaxTrees.WhileCommand;
+
+public final class Encoder implements Visitor {
+
+  // Commands
+  public Object visitAssignCommand(AssignCommand ast, Object o) {
+    Frame frame = (Frame) o;
+    Integer valSize = (Integer) ast.E.visit(this, frame);
+    encodeStore(ast.V, new Frame(frame, valSize.intValue()),
+        valSize.intValue());
+    return null;
+  }
+
+  public Object visitCallCommand(CallCommand ast, Object o) {
+    Frame frame = (Frame) o;
+    Integer argsSize = (Integer) ast.APS.visit(this, frame);
+    ast.I.visit(this, new Frame(frame.level, argsSize));
+    return null;
+  }
+
+  public Object visitEmptyCommand(EmptyCommand ast, Object o) {
+    return null;
+  }
+
+  public Object visitIfCommand(IfCommand ast, Object o) {
+    Frame frame = (Frame) o;
+    int jumpifAddr, jumpAddr;
+
+    Integer valSize = (Integer) ast.E.visit(this, frame);
+    jumpifAddr = nextInstrAddr;
+    emit(Machine.JUMPIFop, Machine.falseRep, Machine.CBr, 0);
+    ast.C1.visit(this, frame);
+    jumpAddr = nextInstrAddr;
+    emit(Machine.JUMPop, 0, Machine.CBr, 0);
+    patch(jumpifAddr, nextInstrAddr);
+    ast.C2.visit(this, frame);
+    patch(jumpAddr, nextInstrAddr);
+    return null;
+  }
+
+  public Object visitLetCommand(LetCommand ast, Object o) {
+    Frame frame = (Frame) o;
+    int extraSize = ((Integer) ast.D.visit(this, frame)).intValue();
+    ast.C.visit(this, new Frame(frame, extraSize));
+    if (extraSize > 0)
+      emit(Machine.POPop, 0, 0, extraSize);
+    return null;
+  }
+
+  public Object visitSequentialCommand(SequentialCommand ast, Object o) {
+    ast.C1.visit(this, o);
+    ast.C2.visit(this, o);
+    return null;
+  }
+
+  public Object visitWhileCommand(WhileCommand ast, Object o) {
+    Frame frame = (Frame) o;
+    int jumpAddr, loopAddr;
+
+    jumpAddr = nextInstrAddr;
+    emit(Machine.JUMPop, 0, Machine.CBr, 0);
+    loopAddr = nextInstrAddr;
+    ast.C.visit(this, frame);
+    patch(jumpAddr, nextInstrAddr);
+    ast.E.visit(this, frame);
+    emit(Machine.JUMPIFop, Machine.trueRep, Machine.CBr, loopAddr);
+    return null;
+  }
+
+  // Expressions
+  public Object visitArrayExpression(ArrayExpression ast, Object o) {
+    ast.type.visit(this, null);
+    return ast.AA.visit(this, o);
+  }
+
+  public Object visitBinaryExpression(BinaryExpression ast, Object o) {
+    Frame frame = (Frame) o;
+    Integer valSize = (Integer) ast.type.visit(this, null);
+    int valSize1 = ((Integer) ast.E1.visit(this, frame)).intValue();
+    Frame frame1 = new Frame(frame, valSize1);
+    int valSize2 = ((Integer) ast.E2.visit(this, frame1)).intValue();
+    Frame frame2 = new Frame(frame.level, valSize1 + valSize2);
+    ast.O.visit(this, frame2);
+    return valSize;
+  }
+
+  public Object visitCallExpression(CallExpression ast, Object o) {
+    Frame frame = (Frame) o;
+    Integer valSize = (Integer) ast.type.visit(this, null);
+    Integer argsSize = (Integer) ast.APS.visit(this, frame);
+    ast.I.visit(this, new Frame(frame.level, argsSize));
+    return valSize;
+  }
+
+  public Object visitCharacterExpression(CharacterExpression ast,
+      Object o) {
+    Frame frame = (Frame) o;
+    Integer valSize = (Integer) ast.type.visit(this, null);
+    emit(Machine.LOADLop, 0, 0, ast.CL.spelling.charAt(1));
+    return valSize;
+  }
+
+  public Object visitEmptyExpression(EmptyExpression ast, Object o) {
+    return new Integer(0);
+  }
+
+  public Object visitIfExpression(IfExpression ast, Object o) {
+    Frame frame = (Frame) o;
+    Integer valSize;
+    int jumpifAddr, jumpAddr;
+
+    ast.type.visit(this, null);
+    ast.E1.visit(this, frame);
+    jumpifAddr = nextInstrAddr;
+    emit(Machine.JUMPIFop, Machine.falseRep, Machine.CBr, 0);
+    valSize = (Integer) ast.E2.visit(this, frame);
+    jumpAddr = nextInstrAddr;
+    emit(Machine.JUMPop, 0, Machine.CBr, 0);
+    patch(jumpifAddr, nextInstrAddr);
+    valSize = (Integer) ast.E3.visit(this, frame);
+    patch(jumpAddr, nextInstrAddr);
+    return valSize;
+  }
+
+  public Object visitIntegerExpression(IntegerExpression ast, Object o) {
+    Frame frame = (Frame) o;
+    Integer valSize = (Integer) ast.type.visit(this, null);
+    emit(Machine.LOADLop, 0, 0, Integer.parseInt(ast.IL.spelling));
+    return valSize;
+  }
+
+  public Object visitLetExpression(LetExpression ast, Object o) {
+    Frame frame = (Frame) o;
+    ast.type.visit(this, null);
+    int extraSize = ((Integer) ast.D.visit(this, frame)).intValue();
+    Frame frame1 = new Frame(frame, extraSize);
+    Integer valSize = (Integer) ast.E.visit(this, frame1);
+    if (extraSize > 0)
+      emit(Machine.POPop, valSize.intValue(), 0, extraSize);
+    return valSize;
+  }
+
+  public Object visitRecordExpression(RecordExpression ast, Object o) {
+    ast.type.visit(this, null);
+    return ast.RA.visit(this, o);
+  }
+
+  public Object visitUnaryExpression(UnaryExpression ast, Object o) {
+    Frame frame = (Frame) o;
+    Integer valSize = (Integer) ast.type.visit(this, null);
+    ast.E.visit(this, frame);
+    ast.O.visit(this, new Frame(frame.level, valSize.intValue()));
+    return valSize;
+  }
+
+  public Object visitVnameExpression(VnameExpression ast, Object o) {
+    Frame frame = (Frame) o;
+    Integer valSize = (Integer) ast.type.visit(this, null);
+    encodeFetch(ast.V, frame, valSize.intValue());
+    return valSize;
+  }
+
+  // Declarations
+  public Object visitBinaryOperatorDeclaration(BinaryOperatorDeclaration ast,
+      Object o) {
+    return new Integer(0);
+  }
+
+  public Object visitConstDeclaration(ConstDeclaration ast, Object o) {
+    Frame frame = (Frame) o;
+    int extraSize = 0;
+
+    if (ast.E instanceof CharacterExpression) {
+      CharacterLiteral CL = ((CharacterExpression) ast.E).CL;
+      ast.entity = new KnownValue(Machine.characterSize,
+          characterValuation(CL.spelling));
+    } else if (ast.E instanceof IntegerExpression) {
+      IntegerLiteral IL = ((IntegerExpression) ast.E).IL;
+      ast.entity = new KnownValue(Machine.integerSize,
+          Integer.parseInt(IL.spelling));
+    } else {
+      int valSize = ((Integer) ast.E.visit(this, frame)).intValue();
+      ast.entity = new UnknownValue(valSize, frame.level, frame.size);
+      extraSize = valSize;
+    }
+    writeTableDetails(ast);
+    return new Integer(extraSize);
+  }
+
+  public Object visitFuncDeclaration(FuncDeclaration ast, Object o) {
+    Frame frame = (Frame) o;
+    int jumpAddr = nextInstrAddr;
+    int argsSize = 0, valSize = 0;
+
+    emit(Machine.JUMPop, 0, Machine.CBr, 0);
+    ast.entity = new KnownRoutine(Machine.closureSize, frame.level, nextInstrAddr);
+    writeTableDetails(ast);
+    if (frame.level == Machine.maxRoutineLevel)
+      reporter.reportRestriction("can't nest routines more than 7 deep");
+    else {
+      Frame frame1 = new Frame(frame.level + 1, 0);
+      argsSize = ((Integer) ast.FPS.visit(this, frame1)).intValue();
+      Frame frame2 = new Frame(frame.level + 1, Machine.linkDataSize);
+      valSize = ((Integer) ast.E.visit(this, frame2)).intValue();
+    }
+    emit(Machine.RETURNop, valSize, 0, argsSize);
+    patch(jumpAddr, nextInstrAddr);
+    return new Integer(0);
+  }
+
+  public Object visitProcDeclaration(ProcDeclaration ast, Object o) {
+    Frame frame = (Frame) o;
+    int jumpAddr = nextInstrAddr;
+    int argsSize = 0;
+
+    emit(Machine.JUMPop, 0, Machine.CBr, 0);
+    ast.entity = new KnownRoutine(Machine.closureSize, frame.level,
+        nextInstrAddr);
+    writeTableDetails(ast);
+    if (frame.level == Machine.maxRoutineLevel)
+      reporter.reportRestriction("can't nest routines so deeply");
+    else {
+      Frame frame1 = new Frame(frame.level + 1, 0);
+      argsSize = ((Integer) ast.FPS.visit(this, frame1)).intValue();
+      Frame frame2 = new Frame(frame.level + 1, Machine.linkDataSize);
+      ast.C.visit(this, frame2);
+    }
+    emit(Machine.RETURNop, 0, 0, argsSize);
+    patch(jumpAddr, nextInstrAddr);
+    return new Integer(0);
+  }
+
+  public Object visitSequentialDeclaration(SequentialDeclaration ast, Object o) {
+    Frame frame = (Frame) o;
+    int extraSize1, extraSize2;
+
+    extraSize1 = ((Integer) ast.D1.visit(this, frame)).intValue();
+    Frame frame1 = new Frame(frame, extraSize1);
+    extraSize2 = ((Integer) ast.D2.visit(this, frame1)).intValue();
+    return new Integer(extraSize1 + extraSize2);
+  }
+
+  public Object visitTypeDeclaration(TypeDeclaration ast, Object o) {
+    // just to ensure the type's representation is decided
+    ast.T.visit(this, null);
+    return new Integer(0);
+  }
+
+  public Object visitUnaryOperatorDeclaration(UnaryOperatorDeclaration ast,
+      Object o) {
+    return new Integer(0);
+  }
+
+  public Object visitVarDeclaration(VarDeclaration ast, Object o) {
+    Frame frame = (Frame) o;
+    int extraSize;
+
+    extraSize = ((Integer) ast.T.visit(this, null)).intValue();
+    emit(Machine.PUSHop, 0, 0, extraSize);
+    ast.entity = new KnownAddress(Machine.addressSize, frame.level, frame.size);
+    writeTableDetails(ast);
+    return new Integer(extraSize);
+  }
+
+  // Array Aggregates
+  public Object visitMultipleArrayAggregate(MultipleArrayAggregate ast,
+      Object o) {
+    Frame frame = (Frame) o;
+    int elemSize = ((Integer) ast.E.visit(this, frame)).intValue();
+    Frame frame1 = new Frame(frame, elemSize);
+    int arraySize = ((Integer) ast.AA.visit(this, frame1)).intValue();
+    return new Integer(elemSize + arraySize);
+  }
+
+  public Object visitSingleArrayAggregate(SingleArrayAggregate ast, Object o) {
+    return ast.E.visit(this, o);
+  }
+
+  // Record Aggregates
+  public Object visitMultipleRecordAggregate(MultipleRecordAggregate ast,
+      Object o) {
+    Frame frame = (Frame) o;
+    int fieldSize = ((Integer) ast.E.visit(this, frame)).intValue();
+    Frame frame1 = new Frame(frame, fieldSize);
+    int recordSize = ((Integer) ast.RA.visit(this, frame1)).intValue();
+    return new Integer(fieldSize + recordSize);
+  }
+
+  public Object visitSingleRecordAggregate(SingleRecordAggregate ast,
+      Object o) {
+    return ast.E.visit(this, o);
+  }
+
+  // Formal Parameters
+  public Object visitConstFormalParameter(ConstFormalParameter ast, Object o) {
+    Frame frame = (Frame) o;
+    int valSize = ((Integer) ast.T.visit(this, null)).intValue();
+    ast.entity = new UnknownValue(valSize, frame.level, -frame.size - valSize);
+    writeTableDetails(ast);
+    return new Integer(valSize);
+  }
+
+  public Object visitFuncFormalParameter(FuncFormalParameter ast, Object o) {
+    Frame frame = (Frame) o;
+    int argsSize = Machine.closureSize;
+    ast.entity = new UnknownRoutine(Machine.closureSize, frame.level,
+        -frame.size - argsSize);
+    writeTableDetails(ast);
+    return new Integer(argsSize);
+  }
+
+  public Object visitProcFormalParameter(ProcFormalParameter ast, Object o) {
+    Frame frame = (Frame) o;
+    int argsSize = Machine.closureSize;
+    ast.entity = new UnknownRoutine(Machine.closureSize, frame.level,
+        -frame.size - argsSize);
+    writeTableDetails(ast);
+    return new Integer(argsSize);
+  }
+
+  public Object visitVarFormalParameter(VarFormalParameter ast, Object o) {
+    Frame frame = (Frame) o;
+    ast.T.visit(this, null);
+    ast.entity = new UnknownAddress(Machine.addressSize, frame.level,
+        -frame.size - Machine.addressSize);
+    writeTableDetails(ast);
+    return new Integer(Machine.addressSize);
+  }
+
+  public Object visitEmptyFormalParameterSequence(
+      EmptyFormalParameterSequence ast, Object o) {
+    return new Integer(0);
+  }
+
+  public Object visitMultipleFormalParameterSequence(
+      MultipleFormalParameterSequence ast, Object o) {
+    Frame frame = (Frame) o;
+    int argsSize1 = ((Integer) ast.FPS.visit(this, frame)).intValue();
+    Frame frame1 = new Frame(frame, argsSize1);
+    int argsSize2 = ((Integer) ast.FP.visit(this, frame1)).intValue();
+    return new Integer(argsSize1 + argsSize2);
+  }
+
+  public Object visitSingleFormalParameterSequence(
+      SingleFormalParameterSequence ast, Object o) {
+    return ast.FP.visit(this, o);
+  }
+
+  // Actual Parameters
+  public Object visitConstActualParameter(ConstActualParameter ast, Object o) {
+    return ast.E.visit(this, o);
+  }
+
+  public Object visitFuncActualParameter(FuncActualParameter ast, Object o) {
+    Frame frame = (Frame) o;
+    if (ast.I.decl.entity instanceof KnownRoutine) {
+      ObjectAddress address = ((KnownRoutine) ast.I.decl.entity).address;
+      // static link, code address
+      emit(Machine.LOADAop, 0, displayRegister(frame.level, address.level), 0);
+      emit(Machine.LOADAop, 0, Machine.CBr, address.displacement);
+    } else if (ast.I.decl.entity instanceof UnknownRoutine) {
+      ObjectAddress address = ((UnknownRoutine) ast.I.decl.entity).address;
+      emit(Machine.LOADop, Machine.closureSize, displayRegister(frame.level,
+          address.level), address.displacement);
+    } else if (ast.I.decl.entity instanceof PrimitiveRoutine) {
+      int displacement = ((PrimitiveRoutine) ast.I.decl.entity).displacement;
+      // static link, code address
+      emit(Machine.LOADAop, 0, Machine.SBr, 0);
+      emit(Machine.LOADAop, 0, Machine.PBr, displacement);
+    }
+    return new Integer(Machine.closureSize);
+  }
+
+  public Object visitProcActualParameter(ProcActualParameter ast, Object o) {
+    Frame frame = (Frame) o;
+    if (ast.I.decl.entity instanceof KnownRoutine) {
+      ObjectAddress address = ((KnownRoutine) ast.I.decl.entity).address;
+      // static link, code address
+      emit(Machine.LOADAop, 0, displayRegister(frame.level, address.level), 0);
+      emit(Machine.LOADAop, 0, Machine.CBr, address.displacement);
+    } else if (ast.I.decl.entity instanceof UnknownRoutine) {
+      ObjectAddress address = ((UnknownRoutine) ast.I.decl.entity).address;
+      emit(Machine.LOADop, Machine.closureSize, displayRegister(frame.level,
+          address.level), address.displacement);
+    } else if (ast.I.decl.entity instanceof PrimitiveRoutine) {
+      int displacement = ((PrimitiveRoutine) ast.I.decl.entity).displacement;
+      // static link, code address
+      emit(Machine.LOADAop, 0, Machine.SBr, 0);
+      emit(Machine.LOADAop, 0, Machine.PBr, displacement);
+    }
+    return new Integer(Machine.closureSize);
+  }
+
+  public Object visitVarActualParameter(VarActualParameter ast, Object o) {
+    encodeFetchAddress(ast.V, (Frame) o);
+    return new Integer(Machine.addressSize);
+  }
+
+  public Object visitEmptyActualParameterSequence(
+      EmptyActualParameterSequence ast, Object o) {
+    return new Integer(0);
+  }
+
+  public Object visitMultipleActualParameterSequence(
+      MultipleActualParameterSequence ast, Object o) {
+    Frame frame = (Frame) o;
+    int argsSize1 = ((Integer) ast.AP.visit(this, frame)).intValue();
+    Frame frame1 = new Frame(frame, argsSize1);
+    int argsSize2 = ((Integer) ast.APS.visit(this, frame1)).intValue();
+    return new Integer(argsSize1 + argsSize2);
+  }
+
+  public Object visitSingleActualParameterSequence(
+      SingleActualParameterSequence ast, Object o) {
+    return ast.AP.visit(this, o);
+  }
+
+  // Type Denoters
+  public Object visitAnyTypeDenoter(AnyTypeDenoter ast, Object o) {
+    return new Integer(0);
+  }
+
+  public Object visitArrayTypeDenoter(ArrayTypeDenoter ast, Object o) {
+    int typeSize;
+    if (ast.entity == null) {
+      int elemSize = ((Integer) ast.T.visit(this, null)).intValue();
+      typeSize = Integer.parseInt(ast.IL.spelling) * elemSize;
+      ast.entity = new TypeRepresentation(typeSize);
+      writeTableDetails(ast);
+    } else
+      typeSize = ast.entity.size;
+    return new Integer(typeSize);
+  }
+
+  public Object visitBoolTypeDenoter(BoolTypeDenoter ast, Object o) {
+    if (ast.entity == null) {
+      ast.entity = new TypeRepresentation(Machine.booleanSize);
+      writeTableDetails(ast);
+    }
+    return new Integer(Machine.booleanSize);
+  }
+
+  public Object visitCharTypeDenoter(CharTypeDenoter ast, Object o) {
+    if (ast.entity == null) {
+      ast.entity = new TypeRepresentation(Machine.characterSize);
+      writeTableDetails(ast);
+    }
+    return new Integer(Machine.characterSize);
+  }
+
+  public Object visitErrorTypeDenoter(ErrorTypeDenoter ast, Object o) {
+    return new Integer(0);
+  }
+
+  public Object visitSimpleTypeDenoter(SimpleTypeDenoter ast,
+      Object o) {
+    return new Integer(0);
+  }
+
+  public Object visitIntTypeDenoter(IntTypeDenoter ast, Object o) {
+    if (ast.entity == null) {
+      ast.entity = new TypeRepresentation(Machine.integerSize);
+      writeTableDetails(ast);
+    }
+    return new Integer(Machine.integerSize);
+  }
+
+  public Object visitRecordTypeDenoter(RecordTypeDenoter ast, Object o) {
+    int typeSize;
+    if (ast.entity == null) {
+      typeSize = ((Integer) ast.FT.visit(this, new Integer(0))).intValue();
+      ast.entity = new TypeRepresentation(typeSize);
+      writeTableDetails(ast);
+    } else
+      typeSize = ast.entity.size;
+    return new Integer(typeSize);
+  }
+
+  public Object visitMultipleFieldTypeDenoter(MultipleFieldTypeDenoter ast,
+      Object o) {
+    int offset = ((Integer) o).intValue();
+    int fieldSize;
+
+    if (ast.entity == null) {
+      fieldSize = ((Integer) ast.T.visit(this, null)).intValue();
+      ast.entity = new Field(fieldSize, offset);
+      writeTableDetails(ast);
+    } else
+      fieldSize = ast.entity.size;
+
+    Integer offset1 = new Integer(offset + fieldSize);
+    int recSize = ((Integer) ast.FT.visit(this, offset1)).intValue();
+    return new Integer(fieldSize + recSize);
+  }
+
+  public Object visitSingleFieldTypeDenoter(SingleFieldTypeDenoter ast,
+      Object o) {
+    int offset = ((Integer) o).intValue();
+    int fieldSize;
+
+    if (ast.entity == null) {
+      fieldSize = ((Integer) ast.T.visit(this, null)).intValue();
+      ast.entity = new Field(fieldSize, offset);
+      writeTableDetails(ast);
+    } else
+      fieldSize = ast.entity.size;
+
+    return new Integer(fieldSize);
+  }
+
+  // Literals, Identifiers and Operators
+  public Object visitCharacterLiteral(CharacterLiteral ast, Object o) {
+    return null;
+  }
+
+  public Object visitIdentifier(Identifier ast, Object o) {
+    Frame frame = (Frame) o;
+    if (ast.decl.entity instanceof KnownRoutine) {
+      ObjectAddress address = ((KnownRoutine) ast.decl.entity).address;
+      emit(Machine.CALLop, displayRegister(frame.level, address.level),
+          Machine.CBr, address.displacement);
+    } else if (ast.decl.entity instanceof UnknownRoutine) {
+      ObjectAddress address = ((UnknownRoutine) ast.decl.entity).address;
+      emit(Machine.LOADop, Machine.closureSize, displayRegister(frame.level,
+          address.level), address.displacement);
+      emit(Machine.CALLIop, 0, 0, 0);
+    } else if (ast.decl.entity instanceof PrimitiveRoutine) {
+      int displacement = ((PrimitiveRoutine) ast.decl.entity).displacement;
+      if (displacement != Machine.idDisplacement)
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, displacement);
+    } else if (ast.decl.entity instanceof EqualityRoutine) { // "=" or "\="
+      int displacement = ((EqualityRoutine) ast.decl.entity).displacement;
+      emit(Machine.LOADLop, 0, 0, frame.size / 2);
+      emit(Machine.CALLop, Machine.SBr, Machine.PBr, displacement);
+    }
+    return null;
+  }
+
+  public Object visitIntegerLiteral(IntegerLiteral ast, Object o) {
+    return null;
+  }
+
+  public Object visitOperator(Operator ast, Object o) {
+    Frame frame = (Frame) o;
+    if (ast.decl.entity instanceof KnownRoutine) {
+      ObjectAddress address = ((KnownRoutine) ast.decl.entity).address;
+      emit(Machine.CALLop, displayRegister(frame.level, address.level),
+          Machine.CBr, address.displacement);
+    } else if (ast.decl.entity instanceof UnknownRoutine) {
+      ObjectAddress address = ((UnknownRoutine) ast.decl.entity).address;
+      emit(Machine.LOADop, Machine.closureSize, displayRegister(frame.level,
+          address.level), address.displacement);
+      emit(Machine.CALLIop, 0, 0, 0);
+    } else if (ast.decl.entity instanceof PrimitiveRoutine) {
+      int displacement = ((PrimitiveRoutine) ast.decl.entity).displacement;
+      if (displacement != Machine.idDisplacement)
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, displacement);
+    } else if (ast.decl.entity instanceof EqualityRoutine) { // "=" or "\="
+      int displacement = ((EqualityRoutine) ast.decl.entity).displacement;
+      emit(Machine.LOADLop, 0, 0, frame.size / 2);
+      emit(Machine.CALLop, Machine.SBr, Machine.PBr, displacement);
+    }
+    return null;
+  }
+
+  // Value-or-variable names
+  public Object visitDotVname(DotVname ast, Object o) {
+    Frame frame = (Frame) o;
+    RuntimeEntity baseObject = (RuntimeEntity) ast.V.visit(this, frame);
+    ast.offset = ast.V.offset + ((Field) ast.I.decl.entity).fieldOffset;
+    // I.decl points to the appropriate record field
+    ast.indexed = ast.V.indexed;
+    return baseObject;
+  }
+
+  public Object visitSimpleVname(SimpleVname ast, Object o) {
+    ast.offset = 0;
+    ast.indexed = false;
+    return ast.I.decl.entity;
+  }
+
+  public Object visitSubscriptVname(SubscriptVname ast, Object o) {
+    Frame frame = (Frame) o;
+    RuntimeEntity baseObject;
+    int elemSize, indexSize;
+
+    baseObject = (RuntimeEntity) ast.V.visit(this, frame);
+    ast.offset = ast.V.offset;
+    ast.indexed = ast.V.indexed;
+    elemSize = ((Integer) ast.type.visit(this, null)).intValue();
+    if (ast.E instanceof IntegerExpression) {
+      IntegerLiteral IL = ((IntegerExpression) ast.E).IL;
+      ast.offset = ast.offset + Integer.parseInt(IL.spelling) * elemSize;
+    } else {
+      // v-name is indexed by a proper expression, not a literal
+      if (ast.indexed)
+        frame.size = frame.size + Machine.integerSize;
+      indexSize = ((Integer) ast.E.visit(this, frame)).intValue();
+      if (elemSize != 1) {
+        emit(Machine.LOADLop, 0, 0, elemSize);
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr,
+            Machine.multDisplacement);
+      }
+      if (ast.indexed)
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+      else
+        ast.indexed = true;
+    }
+    return baseObject;
+  }
+
+  // Programs
+  public Object visitProgram(Program ast, Object o) {
+    return ast.C.visit(this, o);
+  }
+
+  public Encoder(ErrorReporter reporter) {
+    this.reporter = reporter;
+    nextInstrAddr = Machine.CB;
+    elaborateStdEnvironment();
+  }
+
+  private ErrorReporter reporter;
+
+  // Generates code to run a program.
+  // showingTable is true iff entity description details
+  // are to be displayed.
+  public final void encodeRun(Program theAST, boolean showingTable) {
+    tableDetailsReqd = showingTable;
+    // startCodeGeneration();
+    theAST.visit(this, new Frame(0, 0));
+    emit(Machine.HALTop, 0, 0, 0);
+  }
+
+  // Decides run-time representation of a standard constant.
+  private final void elaborateStdConst(Declaration constDeclaration,
+      int value) {
+
+    if (constDeclaration instanceof ConstDeclaration) {
+      ConstDeclaration decl = (ConstDeclaration) constDeclaration;
+      int typeSize = ((Integer) decl.E.type.visit(this, null)).intValue();
+      decl.entity = new KnownValue(typeSize, value);
+      writeTableDetails(constDeclaration);
+    }
+  }
+
+  // Decides run-time representation of a standard routine.
+  private final void elaborateStdPrimRoutine(Declaration routineDeclaration,
+      int routineOffset) {
+    routineDeclaration.entity = new PrimitiveRoutine(Machine.closureSize, routineOffset);
+    writeTableDetails(routineDeclaration);
+  }
+
+  private final void elaborateStdEqRoutine(Declaration routineDeclaration,
+      int routineOffset) {
+    routineDeclaration.entity = new EqualityRoutine(Machine.closureSize, routineOffset);
+    writeTableDetails(routineDeclaration);
+  }
+
+  private final void elaborateStdRoutine(Declaration routineDeclaration,
+      int routineOffset) {
+    routineDeclaration.entity = new KnownRoutine(Machine.closureSize, 0, routineOffset);
+    writeTableDetails(routineDeclaration);
+  }
+
+  private final void elaborateStdEnvironment() {
+    tableDetailsReqd = false;
+    elaborateStdConst(StdEnvironment.falseDecl, Machine.falseRep);
+    elaborateStdConst(StdEnvironment.trueDecl, Machine.trueRep);
+    elaborateStdPrimRoutine(StdEnvironment.notDecl, Machine.notDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.andDecl, Machine.andDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.orDecl, Machine.orDisplacement);
+    elaborateStdConst(StdEnvironment.maxintDecl, Machine.maxintRep);
+    elaborateStdPrimRoutine(StdEnvironment.addDecl, Machine.addDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.subtractDecl, Machine.subDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.multiplyDecl, Machine.multDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.divideDecl, Machine.divDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.moduloDecl, Machine.modDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.lessDecl, Machine.ltDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.notgreaterDecl, Machine.leDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.greaterDecl, Machine.gtDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.notlessDecl, Machine.geDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.chrDecl, Machine.idDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.ordDecl, Machine.idDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.eolDecl, Machine.eolDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.eofDecl, Machine.eofDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.getDecl, Machine.getDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.putDecl, Machine.putDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.getintDecl, Machine.getintDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.putintDecl, Machine.putintDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.geteolDecl, Machine.geteolDisplacement);
+    elaborateStdPrimRoutine(StdEnvironment.puteolDecl, Machine.puteolDisplacement);
+    elaborateStdEqRoutine(StdEnvironment.equalDecl, Machine.eqDisplacement);
+    elaborateStdEqRoutine(StdEnvironment.unequalDecl, Machine.neDisplacement);
+  }
+
+  // Saves the object program in the named file.
+
+  public void saveObjectProgram(String objectName) {
+    FileOutputStream objectFile = null;
+    DataOutputStream objectStream = null;
+
+    int addr;
+
+    try {
+      objectFile = new FileOutputStream(objectName);
+      objectStream = new DataOutputStream(objectFile);
+
+      addr = Machine.CB;
+      for (addr = Machine.CB; addr < nextInstrAddr; addr++)
+        Machine.code[addr].write(objectStream);
+      objectFile.close();
+    } catch (FileNotFoundException s) {
+      System.err.println("Error opening object file: " + s);
+    } catch (IOException s) {
+      System.err.println("Error writing object file: " + s);
+    }
+  }
+
+  boolean tableDetailsReqd;
+
+  public static void writeTableDetails(AST ast) {
+  }
+
+  // OBJECT CODE
+
+  // Implementation notes:
+  // Object code is generated directly into the TAM Code Store, starting at CB.
+  // The address of the next instruction is held in nextInstrAddr.
+
+  private int nextInstrAddr;
+
+  // Appends an instruction, with the given fields, to the object code.
+  private void emit(int op, int n, int r, int d) {
+    Instruction nextInstr = new Instruction();
+    if (n > 255) {
+      reporter.reportRestriction("length of operand can't exceed 255 words");
+      n = 255; // to allow code generation to continue
+    }
+    nextInstr.op = op;
+    nextInstr.n = n;
+    nextInstr.r = r;
+    nextInstr.d = d;
+    if (nextInstrAddr == Machine.PB)
+      reporter.reportRestriction("too many instructions for code segment");
+    else {
+      Machine.code[nextInstrAddr] = nextInstr;
+      nextInstrAddr = nextInstrAddr + 1;
+    }
+  }
+
+  // Patches the d-field of the instruction at address addr.
+  private void patch(int addr, int d) {
+    Machine.code[addr].d = d;
+  }
+
+  // DATA REPRESENTATION
+
+  public int characterValuation(String spelling) {
+    // Returns the machine representation of the given character literal.
+    return spelling.charAt(1);
+    // since the character literal is of the form 'x'}
+  }
+
+  // REGISTERS
+
+  // Returns the register number appropriate for object code at currentLevel
+  // to address a data object at objectLevel.
+  private int displayRegister(int currentLevel, int objectLevel) {
+    if (objectLevel == 0)
+      return Machine.SBr;
+    else if (currentLevel - objectLevel <= 6)
+      return Machine.LBr + currentLevel - objectLevel; // LBr|L1r|...|L6r
+    else {
+      reporter.reportRestriction("can't access data more than 6 levels out");
+      return Machine.L6r; // to allow code generation to continue
+    }
+  }
+
+  // Generates code to fetch the value of a named constant or variable
+  // and push it on to the stack.
+  // currentLevel is the routine level where the vname occurs.
+  // frameSize is the anticipated size of the local stack frame when
+  // the constant or variable is fetched at run-time.
+  // valSize is the size of the constant or variable's value.
+
+  private void encodeStore(Vname V, Frame frame, int valSize) {
+
+    RuntimeEntity baseObject = (RuntimeEntity) V.visit(this, frame);
+    // If indexed = true, code will have been generated to load an index value.
+    if (valSize > 255) {
+      reporter.reportRestriction("can't store values larger than 255 words");
+      valSize = 255; // to allow code generation to continue
+    }
+    if (baseObject instanceof KnownAddress) {
+      ObjectAddress address = ((KnownAddress) baseObject).address;
+      if (V.indexed) {
+        emit(Machine.LOADAop, 0, displayRegister(frame.level, address.level),
+            address.displacement + V.offset);
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+        emit(Machine.STOREIop, valSize, 0, 0);
+      } else {
+        emit(Machine.STOREop, valSize, displayRegister(frame.level,
+            address.level), address.displacement + V.offset);
+      }
+    } else if (baseObject instanceof UnknownAddress) {
+      ObjectAddress address = ((UnknownAddress) baseObject).address;
+      emit(Machine.LOADop, Machine.addressSize, displayRegister(frame.level,
+          address.level), address.displacement);
+      if (V.indexed)
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+      if (V.offset != 0) {
+        emit(Machine.LOADLop, 0, 0, V.offset);
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+      }
+      emit(Machine.STOREIop, valSize, 0, 0);
+    }
+  }
+
+  // Generates code to fetch the value of a named constant or variable
+  // and push it on to the stack.
+  // currentLevel is the routine level where the vname occurs.
+  // frameSize is the anticipated size of the local stack frame when
+  // the constant or variable is fetched at run-time.
+  // valSize is the size of the constant or variable's value.
+
+  private void encodeFetch(Vname V, Frame frame, int valSize) {
+
+    RuntimeEntity baseObject = (RuntimeEntity) V.visit(this, frame);
+    // If indexed = true, code will have been generated to load an index value.
+    if (valSize > 255) {
+      reporter.reportRestriction("can't load values larger than 255 words");
+      valSize = 255; // to allow code generation to continue
+    }
+    if (baseObject instanceof KnownValue) {
+      // presumably offset = 0 and indexed = false
+      int value = ((KnownValue) baseObject).value;
+      emit(Machine.LOADLop, 0, 0, value);
+    } else if ((baseObject instanceof UnknownValue) ||
+        (baseObject instanceof KnownAddress)) {
+      ObjectAddress address = (baseObject instanceof UnknownValue) ? ((UnknownValue) baseObject).address
+          : ((KnownAddress) baseObject).address;
+      if (V.indexed) {
+        emit(Machine.LOADAop, 0, displayRegister(frame.level, address.level),
+            address.displacement + V.offset);
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+        emit(Machine.LOADIop, valSize, 0, 0);
+      } else
+        emit(Machine.LOADop, valSize, displayRegister(frame.level,
+            address.level), address.displacement + V.offset);
+    } else if (baseObject instanceof UnknownAddress) {
+      ObjectAddress address = ((UnknownAddress) baseObject).address;
+      emit(Machine.LOADop, Machine.addressSize, displayRegister(frame.level,
+          address.level), address.displacement);
+      if (V.indexed)
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+      if (V.offset != 0) {
+        emit(Machine.LOADLop, 0, 0, V.offset);
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+      }
+      emit(Machine.LOADIop, valSize, 0, 0);
+    }
+  }
+
+  // Generates code to compute and push the address of a named variable.
+  // vname is the program phrase that names this variable.
+  // currentLevel is the routine level where the vname occurs.
+  // frameSize is the anticipated size of the local stack frame when
+  // the variable is addressed at run-time.
+
+  private void encodeFetchAddress(Vname V, Frame frame) {
+
+    RuntimeEntity baseObject = (RuntimeEntity) V.visit(this, frame);
+    // If indexed = true, code will have been generated to load an index value.
+    if (baseObject instanceof KnownAddress) {
+      ObjectAddress address = ((KnownAddress) baseObject).address;
+      emit(Machine.LOADAop, 0, displayRegister(frame.level, address.level),
+          address.displacement + V.offset);
+      if (V.indexed)
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+    } else if (baseObject instanceof UnknownAddress) {
+      ObjectAddress address = ((UnknownAddress) baseObject).address;
+      emit(Machine.LOADop, Machine.addressSize, displayRegister(frame.level,
+          address.level), address.displacement);
+      if (V.indexed)
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+      if (V.offset != 0) {
+        emit(Machine.LOADLop, 0, 0, V.offset);
+        emit(Machine.CALLop, Machine.SBr, Machine.PBr, Machine.addDisplacement);
+      }
+    }
+  }
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/EqualityRoutine.java

@@ -0,0 +1,30 @@
+/*
+ * @(#)EqualityRoutine.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class EqualityRoutine extends RuntimeEntity {
+
+  public EqualityRoutine() {
+    super();
+  }
+
+  public EqualityRoutine(int size, int displacement) {
+    super(size);
+    this.displacement = displacement;
+  }
+
+  public int displacement;
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/Field.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)Field.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class Field extends RuntimeEntity {
+
+  public Field() {
+    super();
+    fieldOffset = 0;
+  }
+
+  public Field(int size, int fieldOffset) {
+    super(size);
+    this.fieldOffset = fieldOffset;
+  }
+
+  public int fieldOffset;
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/Frame.java

@@ -0,0 +1,46 @@
+/*
+ * @(#)Frame.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class Frame {
+
+  public Frame() {
+    this.level = 0;
+    this.size = 0;
+  }
+
+  public Frame(int level, Integer size) {
+    this.level = level;
+    this.size = size.intValue();
+  }
+
+  public Frame(int level, int size) {
+    this.level = level;
+    this.size = size;
+  }
+
+  public Frame(Frame frame, int sizeIncrement) {
+    this.level = frame.level;
+    this.size = frame.size + sizeIncrement;
+  }
+
+  public Frame(Frame frame, Integer sizeIncrement) {
+    this.level = frame.level;
+    this.size = frame.size + sizeIncrement.intValue();
+  }
+
+  protected int level;
+  protected int size;
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/KnownAddress.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)KnownAddress.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class KnownAddress extends RuntimeEntity {
+
+  public KnownAddress() {
+    super();
+    address = null;
+  }
+
+  public KnownAddress(int size, int level, int displacement) {
+    super(size);
+    address = new ObjectAddress(level, displacement);
+  }
+
+  public ObjectAddress address;
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/KnownRoutine.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)KnownRoutine.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class KnownRoutine extends RuntimeEntity {
+
+  public KnownRoutine() {
+    super();
+    address = null;
+  }
+
+  public KnownRoutine(int size, int level, int displacement) {
+    super(size);
+    address = new ObjectAddress(level, displacement);
+  }
+
+  public ObjectAddress address;
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/KnownValue.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)KnownValue.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class KnownValue extends RuntimeEntity {
+
+  public KnownValue() {
+    super();
+    value = 0;
+  }
+
+  public KnownValue(int size, int value) {
+    super(size);
+    this.value = value;
+  }
+
+  public int value;
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/ObjectAddress.java

@@ -0,0 +1,26 @@
+/*
+ * @(#)ObjectAddress.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public final class ObjectAddress {
+
+  public ObjectAddress(int level, int displacement) {
+    this.level = level;
+    this.displacement = displacement;
+  }
+
+  public int level, displacement;
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/PrimitiveRoutine.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)PrimitiveRoutine.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class PrimitiveRoutine extends RuntimeEntity {
+
+  public PrimitiveRoutine() {
+    super();
+    displacement = 0;
+  }
+
+  public PrimitiveRoutine(int size, int displacement) {
+    super(size);
+    this.displacement = displacement;
+  }
+
+  public int displacement;
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/RuntimeEntity.java

@@ -0,0 +1,33 @@
+/*
+ * @(#)RuntimeEntity.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+// Run-time object
+
+public abstract class RuntimeEntity {
+
+  public final static int maxRoutineLevel = 7;
+
+  public RuntimeEntity() {
+    size = 0;
+  }
+
+  public RuntimeEntity(int size) {
+    this.size = size;
+  }
+
+  public int size;
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/TypeRepresentation.java

@@ -0,0 +1,23 @@
+/*
+ * @(#)TypeRepresentation.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class TypeRepresentation extends RuntimeEntity {
+
+  public TypeRepresentation(int size) {
+    super(size);
+  }
+
+}

Triangle.Compiler/src/main/java/Triangle/CodeGenerator/UnknownAddress.java

@@ -0,0 +1,31 @@
+/*
+ * @(#)UnknownAddress.java                        2.1 2003/10/07
+ *
+ * Copyright (C) 1999, 2003 D.A. Watt and D.F. Brown
+ * Dept. of Computing Science, University of Glasgow, Glasgow G12 8QQ Scotland
+ * and School of Computer and Math Sciences, The Robert Gordon University,
+ * St. Andrew Street, Aberdeen AB25 1HG, Scotland.
+ * All rights reserved.
+ *
+ * This software is provided free for educational use only. It may
+ * not be used for commercial purposes without the prior written permission
+ * of the authors.
+ */
+
+package Triangle.CodeGenerator;
+
+public class UnknownAddress extends RuntimeEntity {
+
+  public UnknownAddress() {
+    super();
+    address = null;
+  }
+
+  public UnknownAddress(int size, int level, int displacement) {
+    super(size);
+    address = new ObjectAddress(level, displacement);
+  }
+
+  public ObjectAddress address;
+
+}