--- /dev/null
+// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
+package org.xwt.js;
+
+import org.xwt.util.*;
+import java.io.*;
+
+/** a block of Forth bytecode */
+class ForthBlock implements Tokens {
+
+ /*
+ * Each instruction is an opcode and an optional literal literal.
+ */
+
+ // opcodes:
+ public static final byte arithmetic = -1; // -- arithmetic operators from parser
+ public static final byte LITERAL = -2; // < String | Number | null > -- push a literal onto the stack
+ public static final byte ARRAY = -3; // < size > -- create a new array of size <size>
+ public static final byte OBJECT = -4; // -- push an empty object onto the stack
+ public static final byte FUNCTION = -5; // < bytecode_block > -- push a new instance of a function with the given bytecode
+ public static final byte DECLARE = -6; // < name > -- declare <name> in the current scope
+ public static final byte THIS = -7; // -- push the topmost non-transparent scope onto the stack
+ public static final byte GET = -8; // -- get stack[0] from stack[1]
+ public static final byte GET_PRESERVE = -80; // -- get stack[0] from stack[1]
+ public static final byte PUT = -9; // -- put stack[1] to key stack[0] on stack[2]; leaves object on the stack
+ public static final byte JT = -13; // < relative_address > -- pop the stack; if true, jump to <relative_address>
+ public static final byte JF = -21; // < relative_address > -- pop the stack; if false, jump to <relative_address>
+ public static final byte JMP = -22; // < relative_address > -- jump to <relative_address>
+ static public final byte POP = -14; // -- discard the top element on the stack
+
+ public static final byte CALL = -15; // < numargs > -- call stack[0] with the topmost <numargs> values as arguments
+
+ public static final byte PUSHKEYS = -19; // -- ??
+ public static final byte EXPR = -20; // -- transitional
+ public static final byte SWAP = -23; // -- transitional
+ public static final byte SCOPE = -30; // -- transitional
+ public static final byte LOOP = -40; // -- transitional
+ public static final byte DUP = -50; // -- transitional
+ public static final byte LABEL = -60; // -- transitional
+
+ int line;
+ String sourceName;
+ int[] op = new int[10];
+ Object[] arg = new Object[10];
+ int size = 0;
+
+ public ForthBlock(int line, String sourceName) { this.line = line; this.sourceName = sourceName; }
+ public ForthBlock(int line, String sourceName, int op_, Object arg_) { this(line, sourceName); add(op_, arg_); }
+
+ public int size() { return size; }
+ public void set(int pos, int op_, Object arg_) { op[pos] = op_; arg[pos] = arg_; }
+ public ForthBlock add(int op_) { return add(op_, null); }
+ public ForthBlock add(int op_, Object arg_) {
+ if (size == op.length - 1) {
+ int[] op2 = new int[op.length * 2]; System.arraycopy(op, 0, op2, 0, op.length); op = op2;
+ Object[] arg2 = new Object[op.length * 2]; System.arraycopy(arg, 0, arg2, 0, arg.length); arg = arg2;
+ }
+ op[size] = op_;
+ arg[size] = arg_;
+ size++;
+ return this;
+ }
+
+ public Object eval(final JS.Scope s) throws ControlTransferException, JS.Exn {
+ return eval(s, new Stack());
+ }
+ public Object eval(final JS.Scope s, Stack t) throws ControlTransferException {
+ for(int i=0; i<size; i++)
+ switch(op[i]) {
+ case LABEL: break; // FIXME
+ case LITERAL: t.push(arg[i]); break;
+ case OBJECT: t.push(new JS.Obj()); break;
+ case ARRAY: t.push(new JS.Array(JS.toNumber(arg[i]).intValue())); break;
+ case DECLARE: s.declare((String)t.pop()); break;
+ case THIS: t.push(s); break; // FIXME: transparents
+ case JT: if (JS.toBoolean(t.pop())) i += JS.toNumber(arg[i]).intValue() - 1; break;
+ case JF: if (!JS.toBoolean(t.pop())) i += JS.toNumber(arg[i]).intValue() - 1; break;
+ case JMP: i += JS.toNumber(arg[i]).intValue() - 1; break;
+ case POP: t.pop(); break;
+ case SWAP: t.swap(); break;
+ case DUP: t.push(t.peek()); break;
+ case NOP: break;
+ case EXPR: t.push(((ForthBlock)arg[i]).eval(s)); break;
+ case SCOPE: t.push(((ForthBlock)arg[i]).eval(new JS.Scope(s), t)); break;
+
+ case ASSERT: if (!JS.toBoolean(t.pop())) throw new EvaluatorException(line, sourceName, "assertion failed"); break;
+ case RETURN: throw new ReturnException(t.pop());
+ case THROW: throw new JS.Exn(t.pop());
+
+ case TRY: break;
+ case INSTANCEOF: break;
+ case TYPEOF: break;
+ case PUSHKEYS: {
+ Object o = t.peek();
+ Object[] keys = ((JS)o).keys();
+ JS.Array a = new JS.Array();
+ a.setSize(keys.length);
+ for(int j=0; j<keys.length; j++) a.setElementAt(keys[j], j);
+ t.push(a);
+ break;
+ }
+
+ case Lexer.BITNOT: t.push(new Long(~JS.toLong(t.pop()))); break;
+ case Lexer.BANG: t.push(new Boolean(!JS.toBoolean(t.pop()))); break;
+
+ case Lexer.BREAK: {
+ // FIXME: make sure this can only appear in proper places
+ return Boolean.FALSE;
+ }
+ case Lexer.CONTINUE: {
+ // FIXME: make sure this can only appear in proper places
+ return Boolean.TRUE;
+ }
+ case LOOP: {
+ ForthBlock loop = (ForthBlock)arg[i];
+ Stack t2 = new Stack();
+ t2.push(Boolean.TRUE);
+ while (true) {
+ Boolean result;
+ try {
+ result = (Boolean)loop.eval(new JS.Scope(s), t2);
+ } catch (ContinueException c) {
+ result = Boolean.TRUE;
+ } catch (BreakException b) {
+ result = Boolean.FALSE;
+ }
+ if (result == Boolean.FALSE) break;
+ t2 = new Stack();
+ t2.push(Boolean.FALSE);
+ }
+ break;
+ }
+
+ case PUT: {
+ Object val = t.pop();
+ Object key = t.pop();
+ ((JS)t.peek()).put(key, val);
+ t.push(val);
+ break;
+ }
+
+ case GET: {
+ Object v = t.pop();
+ Object o = t.pop();
+ t.push(doGet(o, v));
+ break;
+ }
+ case GET_PRESERVE: {
+ Object v = t.pop();
+ Object o = t.peek();
+ t.push(v);
+ t.push(doGet(o, v));
+ break;
+ }
+
+ case CALL: {
+ JS.Array arguments = new JS.Array();
+ int numArgs = JS.toNumber(arg[i]).intValue();
+ arguments.setSize(numArgs);
+ for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(t.pop(), j);
+ JS.Function f = (JS.Function)t.pop();
+ if (f == null) throw new JS.Exn(new EvaluatorException(line, sourceName, "attempted to call null"));
+ t.push(f.call(arguments));
+ break;
+ }
+
+ case FUNCTION: {
+ final ForthBlock myBytes = (ForthBlock)arg[i];
+ t.push(new JS.Function() {
+ public String toString() { return sourceName + ":" + line; }
+ public String getSourceName() throws JS.Exn { return sourceName; }
+ public Object _call(final JS.Array args) throws JS.Exn {
+ Function save = JS.getCurrentFunction();
+ JS.currentFunction.put(java.lang.Thread.currentThread(), this);
+ JS.Scope scope = new JS.Scope(s) {
+ // FIXME
+ public String getSourceName() { return sourceName; }
+ public Object get(Object key) throws JS.Exn {
+ if (key.equals("trapee")) return org.xwt.Trap.currentTrapee();
+ else if (key.equals("cascade")) return org.xwt.Trap.cascadeFunction;
+ return super.get(key);
+ }
+ };
+ Stack t0 = new Stack();
+ t0.push(args);
+ try {
+ return myBytes.eval(scope, t0);
+ } catch (ReturnException r) {
+ return r.retval;
+ } catch (ControlTransferException c) {
+ throw new EvaluatorException(line, sourceName, "error, ControlTransferException tried to leave a function: " + c);
+ } finally {
+ if (save == null) JS.currentFunction.remove(java.lang.Thread.currentThread());
+ else JS.currentFunction.put(java.lang.Thread.currentThread(), save);
+ }
+ }
+ });
+ break;
+ }
+
+ case Lexer.INC: case Lexer.DEC: {
+ boolean isPrefix = JS.toBoolean(arg[i]);
+ Object key = t.pop();
+ JS obj = (JS)t.pop();
+ Number num = JS.toNumber(obj.get(key));
+ Number val = new Double(op[i] == Lexer.INC ? num.doubleValue() + 1.0 : num.doubleValue() - 1.0);
+ obj.put(key, val);
+ t.push(isPrefix ? val : num);
+ break;
+ }
+
+ default: {
+ Object right = t.pop();
+ Object left = t.pop();
+ switch(op[i]) {
+
+ case Lexer.BITOR: t.push(new Long(JS.toLong(left) | JS.toLong(right))); break;
+ case Lexer.BITXOR: t.push(new Long(JS.toLong(left) ^ JS.toLong(right))); break;
+ case Lexer.BITAND: t.push(new Long(JS.toLong(left) & JS.toLong(right))); break;
+
+ case Lexer.ADD: {
+ Object l = left;
+ Object r = right;
+ if (l instanceof String || r instanceof String) {
+ if (l == null) l = "null";
+ if (r == null) r = "null";
+ if (l instanceof Number && ((Number)l).doubleValue() == ((Number)l).longValue())
+ l = new Long(((Number)l).longValue());
+ if (r instanceof Number && ((Number)r).doubleValue() == ((Number)r).longValue())
+ r = new Long(((Number)r).longValue());
+ t.push(l.toString() + r.toString()); break;
+ }
+ t.push(new Double(JS.toDouble(l) + JS.toDouble(r))); break;
+ }
+
+ case Lexer.SUB: t.push(new Double(JS.toDouble(left) - JS.toDouble(right))); break;
+ case Lexer.MUL: t.push(new Double(JS.toDouble(left) * JS.toDouble(right))); break;
+ case Lexer.DIV: t.push(new Double(JS.toDouble(left) / JS.toDouble(right))); break;
+ case Lexer.MOD: t.push(new Double(JS.toDouble(left) % JS.toDouble(right))); break;
+
+ case Lexer.LSH: t.push(new Long(JS.toLong(left) << JS.toLong(right))); break;
+ case Lexer.RSH: t.push(new Long(JS.toLong(left) >> JS.toLong(right))); break;
+ case Lexer.URSH: t.push(new Long(JS.toLong(left) >>> JS.toLong(right))); break;
+
+ // FIXME: these need to work on strings
+ case Lexer.LT: t.push(JS.toDouble(left) < JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
+ case Lexer.LE: t.push(JS.toDouble(left) <= JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
+ case Lexer.GT: t.push(JS.toDouble(left) > JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
+ case Lexer.GE: t.push(JS.toDouble(left) >= JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
+
+ case Lexer.EQ:
+ case Lexer.NE: {
+ // FIXME: should use Javascript coercion-equality rules
+ Object l = left;
+ Object r = right;
+ boolean ret;
+ if (l == null) { Object tmp = r; r = l; l = tmp; }
+ if (l == null && r == null) ret = true;
+ else if (l instanceof Boolean) ret = new Boolean(JS.toBoolean(r)).equals(l);
+ else if (l instanceof Number) ret = JS.toNumber(r).doubleValue() == JS.toNumber(l).doubleValue();
+ else if (l instanceof String) ret = r != null && l.equals(r.toString());
+ else ret = l.equals(r);
+ t.push(new Boolean(op[i] == Lexer.EQ ? ret : !ret)); break;
+ }
+
+ default: throw new Error("unknown opcode " + op[i]);
+ } }
+ }
+ if (t.size() != 1) {
+ throw new EvaluatorException(line, sourceName, "eval() terminated with " + t.size() + " elements on the stack; one expected");
+ }
+ return t.pop();
+ }
+
+ public Object doGet(final Object o, final Object v) {
+ if (o == null) throw new EvaluatorException(line, sourceName, "tried to get property \"" + v + "\" from the null value");
+ if (o instanceof String) {
+ if (v.equals("length")) return new Integer(((String)o).length());
+ else if (v.equals("substring")) return new JS.Function() {
+ public Object _call(JS.Array args) {
+ if (args.length() == 1) return ((String)o).substring(JS.toNumber(args.elementAt(0)).intValue());
+ else if (args.length() == 2) return ((String)o).substring(JS.toNumber(args.elementAt(0)).intValue(),
+ JS.toNumber(args.elementAt(1)).intValue());
+ else throw new Error("String.substring() can only take one or two arguments");
+ }
+ };
+ else if (v.equals("toLowerCase")) return new JS.Function() {
+ public Object _call(JS.Array args) {
+ return ((String)o).toLowerCase();
+ } };
+ else if (v.equals("toUpperCase")) return new JS.Function() {
+ public Object _call(JS.Array args) {
+ return ((String)o).toString().toUpperCase();
+ } };
+ else if (v.equals("charAt")) return new JS.Function() {
+ public Object _call(JS.Array args) {
+ return ((String)o).charAt(JS.toNumber(args.elementAt(0)).intValue()) + "";
+ } };
+ else if (v.equals("lastIndexOf")) return new JS.Function() {
+ public Object _call(JS.Array args) {
+ if (args.length() != 1) return null;
+ return new Integer(((String)o).lastIndexOf(args.elementAt(0).toString()));
+ } };
+ else if (v.equals("indexOf")) return new JS.Function() {
+ public Object _call(JS.Array args) {
+ if (args.length() != 1) return null;
+ return new Integer(((String)o).indexOf(args.elementAt(0).toString()));
+ } };
+ throw new Error("Not Implemented: propery " + v + " on String objects");
+ } else if (o instanceof Boolean) {
+ throw new Error("Not Implemented: properties on Boolean objects");
+ } else if (o instanceof Number) {
+ Log.log(this, "Not Implemented: properties on Number objects");
+ return null;
+ //throw new Error("Not Implemented: properties on Number objects");
+ } else if (o instanceof JS) {
+ return ((JS)o).get(v);
+ }
+ return null;
+ }
+
+ static class Stack {
+ public Object[] os = new Object[256];
+ private int size = 0;
+ public void push(Object o) { os[size++] = o; }
+ public Object pop() { return os[--size]; }
+ public Object peek() { return os[size - 1]; }
+ public void swap() { Object temp = os[size - 1]; os[size - 1] = os[size - 2]; os[size - 2] = temp; }
+ public int size() { return size; }
+ }
+
+ static class EvaluatorException extends RuntimeException {
+ public EvaluatorException(int line, String sourceName, String s) { super(sourceName + ":" + line + " " + s); }
+ }
+
+ static abstract class ControlTransferException extends Exception { }
+ static class BreakException extends ControlTransferException {
+ public String label;
+ BreakException(String label) { this.label = label; }
+ }
+ static class ContinueException extends ControlTransferException {
+ public String label;
+ ContinueException(String label) { this.label = label; }
+ }
+ static class ReturnException extends ControlTransferException {
+ public Object retval;
+ ReturnException(Object retval) { this.retval = retval; }
+ }
+
+}
import org.xwt.util.*;
import java.io.*;
-
-/** parses a stream of lexed tokens into a tree of Expr's */
+/** parses a stream of lexed tokens into ForthBlock's */
public class Parser extends Lexer {
// Constructors //////////////////////////////////////////////////////
public static void main(String[] s) throws Exception {
Parser p = new Parser(new InputStreamReader(System.in), "stdin", 0);
while(true) {
- Expr block = p.parseBlock(false);
+ ForthBlock block = p.parseStatement(false);
if (block == null) return;
System.out.println(block);
if (p.peekToken() == -1) return;
}
/** parses the largest possible expression */
- public Expr parseMaximalExpr() throws IOException { return parseMaximalExpr(null, -1); }
- public Expr parseMaximalExpr(Expr prefix, int minPrecedence) throws IOException {
+ public ForthBlock parseMaximalForthBlock() throws IOException { return parseMaximalForthBlock(null, -1); }
+ public ForthBlock parseMaximalForthBlock(ForthBlock prefix, int minPrecedence) throws IOException {
while(true) {
if (peekToken() == -1) break;
- Expr save = prefix;
- prefix = parseSingleExpr(prefix, minPrecedence);
+ ForthBlock save = prefix;
+ prefix = parseSingleForthBlock(prefix, minPrecedence);
if (save == prefix) break;
- if (prefix == null) throw new ParserException("parseSingleExpr() returned null");
+ if (prefix == null) throw new ParserException("parseSingleForthBlock() returned null");
}
return prefix;
}
- public Expr parseSingleExpr(Expr prefix, int minPrecedence) throws IOException {
- Expr e1 = null, e2 = null, e3 = null, head = null, tail = null, ret = null;
+ public ForthBlock parseSingleForthBlock(ForthBlock prefix, int minPrecedence) throws IOException {
+ ForthBlock e1 = null, e2 = null, e3 = null, head = null, tail = null, ret = null;
int tok = peekToken();
- if (minPrecedence > 0 &&
- tok < precedence.length &&
- precedence[tok] != 0 &&
- (isRightAssociative[tok] ?
- (precedence[tok] < minPrecedence) :
- (precedence[tok] <= minPrecedence))) {
+ if (minPrecedence > 0 && tok < precedence.length && precedence[tok] != 0 &&
+ (isRightAssociative[tok] ? (precedence[tok] < minPrecedence) : (precedence[tok] <= minPrecedence)))
return prefix;
- }
+
getToken();
int curLine = line;
- // these case arms match the precedence of operators; each arm is a precedence level.
switch (tok) {
case VAR: {
if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode b = new ByteCode(curLine);
- b.add(b.THIS, NO_ARG);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
+ b.add(b.THIS);
while(true) {
consume(NAME);
String name = string;
- b.add(b.DECLARE, name);
+ b.add(b.LITERAL, name);
+ b.add(b.DECLARE);
if (peekToken() == ASSIGN) {
b.add(b.LITERAL, name);
consume(ASSIGN);
- b.add(b.EXPR, parseMaximalExpr());
- b.add(b.PUT, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.EXPR, parseMaximalForthBlock());
+ b.add(b.PUT);
+ b.add(b.POP);
}
if (peekToken() != COMMA) break;
consume(COMMA);
case IF: {
if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
consume(LP);
- b.add(b.EXPR, parseMaximalExpr());
+ b.add(b.EXPR, parseMaximalForthBlock());
consume(RP);
b.add(b.JF, new Integer(3));
- b.add(b.EXPR, parseBlock(false));
+ b.add(b.EXPR, parseStatement(false));
b.add(b.JMP, new Integer(2));
if (peekToken() != ELSE) return b.add(b.LITERAL, null);
consume(ELSE);
- b.add(b.EXPR, parseBlock(false));
+ b.add(b.EXPR, parseStatement(false));
return b;
}
case ASSIGN_DIV: if (tok == ASSIGN_DIV) tok = DIV;
case ASSIGN_MOD: if (tok == ASSIGN_MOD) tok = MOD;
{
- ByteCode b = (ByteCode)prefix;
+ ForthBlock b = (ForthBlock)prefix;
b.set(b.size() - 1, b.GET_PRESERVE, new Boolean(true));
- b.add(b.EXPR, parseMaximalExpr(null, precedence[tok]));
- b.add(tok, NO_ARG);
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.EXPR, parseMaximalForthBlock(null, precedence[tok]));
+ b.add(tok);
+ b.add(b.PUT);
+ b.add(b.SWAP);
+ b.add(b.POP);
return b;
}
case INC: case DEC:
if (prefix == null) {
// prefix
- ByteCode b = (ByteCode)parseMaximalExpr(null, precedence[tok]);
+ ForthBlock b = (ForthBlock)parseMaximalForthBlock(null, precedence[tok]);
b.set(b.size() - 1, tok, new Boolean(true));
return b;
} else {
// postfix
- ByteCode b = (ByteCode)prefix;
+ ForthBlock b = (ForthBlock)prefix;
b.set(b.size() - 1, tok, new Boolean(false));
return b;
}
case LP:
if (prefix == null) { // grouping
- ByteCode b = new ByteCode(curLine, ByteCode.EXPR, parseMaximalExpr());
+ ForthBlock b = new ForthBlock(curLine, sourceName, ForthBlock.EXPR, parseMaximalForthBlock());
consume(RP);
return b;
} else { // invocation
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
int i = 0;
b.add(b.EXPR, prefix);
while(peekToken() != RP) {
- b.add(b.EXPR, parseMaximalExpr());
+ b.add(b.EXPR, parseMaximalForthBlock());
i++;
if (peekToken() == RP) break;
consume(COMMA);
case BANG: case BITNOT: case INSTANCEOF: case TYPEOF: {
if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode b = new ByteCode(curLine);
- b.add(b.EXPR, parseMaximalExpr(null, precedence[tok]));
- b.add(tok, NO_ARG);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
+ b.add(b.EXPR, parseMaximalForthBlock(null, precedence[tok]));
+ b.add(tok);
return b;
}
case SUB:
if (prefix == null && peekToken() == NUMBER) {
getToken();
- return new ByteCode(curLine, ByteCode.LITERAL, new Double(number.doubleValue() * -1));
+ return new ForthBlock(curLine, sourceName, ForthBlock.LITERAL, new Double(number.doubleValue() * -1));
} // else fall through
case BITOR: case BITXOR: case BITAND: case SHEQ: case SHNE: case LSH:
case RSH: case URSH: case ADD: case MUL: case DIV: case MOD:
case GT: case GE: case EQ: case NE: case LT: case LE: {
if (prefix == null) throw new ParserException("the " + codeToString[tok] + " token cannot start an expression");
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
b.add(b.EXPR, prefix);
- b.add(b.EXPR, parseMaximalExpr(null, precedence[tok]));
- b.add(tok, NO_ARG);
+ b.add(b.EXPR, parseMaximalForthBlock(null, precedence[tok]));
+ b.add(tok);
return b;
}
// includes short-circuit logic
case OR: case AND: {
if (prefix == null) throw new ParserException("the " + codeToString[tok] + " token cannot start an expression");
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
b.add(b.LITERAL, tok == AND ? new Boolean(false) : new Boolean(true));
b.add(b.EXPR, prefix);
b.add(tok == AND ? b.JF : b.JT, new Integer(3));
- b.add(b.POP, NO_ARG);
- b.add(b.EXPR, parseMaximalExpr(null, precedence[tok]));
- return b;
- }
-
- case ASSIGN: {
- if (prefix == null) throw new ParserException("the " + codeToString[tok] + " token cannot start an expression");
- ByteCode b = new ByteCode(curLine);
- b.add(b.THIS, NO_ARG);
- b.add(b.LITERAL, prefix.string); // FIXME, this is ass-ugly
- b.add(b.EXPR, parseMaximalExpr(null, precedence[ASSIGN]));
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.POP);
+ b.add(b.EXPR, parseMaximalForthBlock(null, precedence[tok]));
return b;
}
case NUMBER:
if (prefix != null) { pushBackToken(); return prefix; }
- return new ByteCode(curLine, ByteCode.LITERAL, number);
+ return new ForthBlock(curLine, sourceName, ForthBlock.LITERAL, number);
case STRING:
if (prefix != null) { pushBackToken(); return prefix; }
- return new ByteCode(curLine, ByteCode.LITERAL, string);
+ return new ForthBlock(curLine, sourceName, ForthBlock.LITERAL, string);
case NULL: case TRUE: case FALSE: case NOP:
if (prefix != null) { pushBackToken(); return prefix; }
- return new ByteCode(curLine, ByteCode.LITERAL, (tok == NULL || tok == NOP) ? null : new Boolean(tok == TRUE));
+ return new ForthBlock(curLine, sourceName, ForthBlock.LITERAL, (tok == NULL || tok == NOP) ? null : new Boolean(tok == TRUE));
case COMMA: pushBackToken(); return prefix;
case THIS:
if (prefix != null) { pushBackToken(); return prefix; }
- return new ByteCode(curLine, ByteCode.THIS, NO_ARG);
-
- // potential lvalues
+ return new ForthBlock(curLine, sourceName, ForthBlock.THIS, null);
case NAME: {
if (prefix != null) { pushBackToken(); return prefix; }
String name = string;
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
if (peekToken() == ASSIGN) {
consume(ASSIGN);
- b.add(ByteCode.THIS, NO_ARG);
- b.add(ByteCode.LITERAL, name);
- b.add(ByteCode.EXPR, parseMaximalExpr(null, minPrecedence));
- b.add(ByteCode.PUT, NO_ARG);
- b.add(ByteCode.SWAP, NO_ARG);
- b.add(ByteCode.POP, NO_ARG);
+ b.add(ForthBlock.THIS);
+ b.add(ForthBlock.LITERAL, name);
+ b.add(ForthBlock.EXPR, parseMaximalForthBlock(null, minPrecedence));
+ b.add(ForthBlock.PUT);
+ b.add(ForthBlock.SWAP);
+ b.add(ForthBlock.POP);
return b;
} else {
- b.add(ByteCode.THIS, NO_ARG);
- b.add(ByteCode.LITERAL, name);
- b.add(ByteCode.GET, NO_ARG);
- return parseMaximalExpr(b, minPrecedence);
+ b.add(ForthBlock.THIS);
+ b.add(ForthBlock.LITERAL, name);
+ b.add(ForthBlock.GET);
+ return parseMaximalForthBlock(b, minPrecedence);
}
}
case DOT: {
consume(NAME);
String target = string;
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
b.add(b.EXPR, prefix);
if (peekToken() == ASSIGN) {
consume(ASSIGN);
- Expr val = parseMaximalExpr();
+ ForthBlock val = parseMaximalForthBlock();
b.add(b.LITERAL, target);
b.add(b.EXPR, val);
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.PUT);
+ b.add(b.SWAP);
+ b.add(b.POP);
} else {
b.add(b.LITERAL, target);
- b.add(b.GET, NO_ARG);
+ b.add(b.GET);
}
return b;
}
case LB: {
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
if (prefix == null) {
b.add(b.ARRAY, new Integer(0));
int i = 0;
while(true) {
- Expr e = parseMaximalExpr();
+ ForthBlock e = parseMaximalForthBlock();
if (e == null && peekToken() == RB) { consume(RB); return b; }
b.add(b.LITERAL, new Integer(i++));
if (e == null) b.add(b.LITERAL, null);
else b.add(b.EXPR, e);
- b.add(b.PUT, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.PUT);
+ b.add(b.POP);
if (peekToken() == RB) { consume(RB); return b; }
consume(COMMA);
}
} else {
b.add(b.EXPR, prefix);
- b.add(b.EXPR, parseMaximalExpr());
+ b.add(b.EXPR, parseMaximalForthBlock());
consume(RB);
if (peekToken() == ASSIGN) {
consume(ASSIGN);
- b.add(b.EXPR, parseMaximalExpr());
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.EXPR, parseMaximalForthBlock());
+ b.add(b.PUT);
+ b.add(b.SWAP);
+ b.add(b.POP);
} else {
- b.add(b.GET, NO_ARG);
+ b.add(b.GET);
}
return b;
}
case LC: {
if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
b.add(b.OBJECT, null);
if (peekToken() == RC) { consume(RC); return b; }
while(true) {
getToken();
b.add(b.LITERAL, string);
consume(COLON);
- b.add(b.EXPR, parseMaximalExpr());
- b.add(b.PUT, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.EXPR, parseMaximalForthBlock());
+ b.add(b.PUT);
+ b.add(b.POP);
if (peekToken() == RC) { consume(RC); return b; }
consume(COMMA);
if (peekToken() == RC) { consume(RC); return b; }
}
case HOOK: {
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
b.add(b.EXPR, prefix);
b.add(b.JF, new Integer(3));
- b.add(b.EXPR, parseMaximalExpr());
+ b.add(b.EXPR, parseMaximalForthBlock());
b.add(b.JMP, new Integer(2));
consume(COLON);
- b.add(b.EXPR, parseMaximalExpr());
+ b.add(b.EXPR, parseMaximalForthBlock());
return b;
}
case FUNCTION: {
if (prefix != null) { pushBackToken(); return prefix; }
consume(LP);
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
int numArgs = 0;
- b.add(b.THIS, NO_ARG);
- b.add(b.SWAP, NO_ARG);
+ b.add(b.THIS);
+ b.add(b.SWAP);
b.add(b.LITERAL, "arguments");
b.add(b.LITERAL, "arguments");
- b.add(b.DECLARE, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.PUT, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.DECLARE);
+ b.add(b.SWAP);
+ b.add(b.PUT);
+ b.add(b.SWAP);
+ b.add(b.POP);
if (peekToken() == RP) consume(RP);
else while(true) {
if (peekToken() == COMMA) {
// declare the name
b.add(b.LITERAL, string);
- b.add(b.DECLARE, NO_ARG);
+ b.add(b.DECLARE);
// retrieve it from the arguments array
b.add(b.LITERAL, new Integer(numArgs));
- b.add(b.GET_PRESERVE, NO_ARG);
- b.add(b.SWAP, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.GET_PRESERVE);
+ b.add(b.SWAP);
+ b.add(b.POP);
// put it to the current scope
- b.add(b.THIS, NO_ARG);
- b.add(b.SWAP, NO_ARG);
+ b.add(b.THIS);
+ b.add(b.SWAP);
b.add(b.LITERAL, string);
- b.add(b.SWAP, NO_ARG);
- b.add(b.PUT, NO_ARG);
+ b.add(b.SWAP);
+ b.add(b.PUT);
// clean the stack
- b.add(b.POP, NO_ARG);
- b.add(b.POP, NO_ARG);
+ b.add(b.POP);
+ b.add(b.POP);
if (peekToken() == RP) { consume(RP); break; }
consume(COMMA);
numArgs++;
}
// pop off the arguments array
- b.add(b.POP, NO_ARG);
- parseBlock(true, b);
- return new ByteCode(curLine, b.FUNCTION, b);
+ b.add(b.POP);
+ parseStatement(true, b);
+ return new ForthBlock(curLine, sourceName, b.FUNCTION, b);
}
case WHILE: {
if (prefix != null) { pushBackToken(); return prefix; }
consume(LP);
- ByteCode r = new ByteCode(curLine);
- ByteCode loop = new ByteCode(curLine);
+ ForthBlock r = new ForthBlock(curLine, sourceName);
+ ForthBlock loop = new ForthBlock(curLine, sourceName);
r.add(loop.LOOP, loop);
r.add(r.LITERAL, null);
- loop.add(loop.EXPR, parseMaximalExpr());
+ loop.add(loop.EXPR, parseMaximalForthBlock());
loop.add(loop.JT, new Integer(2));
- loop.add(Lexer.BREAK, NO_ARG);
+ loop.add(Lexer.BREAK);
consume(RP);
- parseBlock(false, loop);
+ parseStatement(false, loop);
// if we fall out of the end, definately continue
- loop.add(CONTINUE, NO_ARG);
+ loop.add(CONTINUE);
return r;
}
case SWITCH: {
if (prefix != null) { pushBackToken(); return prefix; }
consume(LP);
- ByteCode r = new ByteCode(curLine);
- ByteCode loop = new ByteCode(curLine);
+ ForthBlock r = new ForthBlock(curLine, sourceName);
+ ForthBlock loop = new ForthBlock(curLine, sourceName);
r.add(loop.LOOP, loop);
r.add(r.LITERAL, null);
- loop.add(loop.EXPR, parseMaximalExpr());
+ loop.add(loop.EXPR, parseMaximalForthBlock());
consume(RP);
consume(LC);
while(true) {
- Expr caseExpr;
+ ForthBlock caseForthBlock;
tok = getToken();
if (tok == CASE) {
- loop.add(loop.DUP, NO_ARG);
- loop.add(loop.EXPR, parseMaximalExpr());
- loop.add(EQ, NO_ARG);
+ loop.add(loop.DUP);
+ loop.add(loop.EXPR, parseMaximalForthBlock());
+ loop.add(EQ);
loop.add(loop.JF, new Integer(2));
} else if (tok != DEFAULT) throw new ParserException("expected CASE or DEFAULT");
consume(COLON);
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
while(peekToken() != CASE && peekToken() != DEFAULT && peekToken() != RC) {
- if ((e1 = parseBlock(false)) == null) break;
+ if ((e1 = parseStatement(false)) == null) break;
b.add(b.EXPR, e1);
}
loop.add(loop.EXPR, b);
if (peekToken() == RC) {
consume(RC);
- r.add(BREAK, NO_ARG);
+ r.add(BREAK);
return r;
}
}
case DO: {
if (prefix != null) { pushBackToken(); return prefix; }
- ByteCode r = new ByteCode(curLine);
- ByteCode loop = new ByteCode(curLine);
+ ForthBlock r = new ForthBlock(curLine, sourceName);
+ ForthBlock loop = new ForthBlock(curLine, sourceName);
r.add(loop.LOOP, loop);
r.add(r.LITERAL, null);
- parseBlock(false, loop);
+ parseStatement(false, loop);
consume(WHILE);
consume(LP);
- loop.add(loop.EXPR, parseMaximalExpr());
+ loop.add(loop.EXPR, parseMaximalForthBlock());
loop.add(loop.JT, new Integer(2));
- loop.add(Lexer.BREAK, NO_ARG);
- loop.add(Lexer.CONTINUE, NO_ARG);
+ loop.add(Lexer.BREAK);
+ loop.add(Lexer.CONTINUE);
consume(RP);
consume(SEMI);
return r;
// FIXME: don't just ignore this!
// We deliberately allow you to omit braces in catch{}/finally{} if they are single statements...
if (prefix != null) { pushBackToken(); return prefix; }
- Expr tryBlock = parseBlock(true);
+ ForthBlock tryBlock = parseStatement(true);
tok = peekToken();
if (tok == CATCH) {
boolean forIn = peekToken() == IN;
pushBackToken(tok, varName);
- ByteCode b = new ByteCode(curLine);
+ ForthBlock b = new ForthBlock(curLine, sourceName);
if (forIn) {
consume(NAME);
consume(IN);
- b.add(b.EXPR, parseMaximalExpr());
- b.add(b.PUSHKEYS, NO_ARG);
+ b.add(b.EXPR, parseMaximalForthBlock());
+ b.add(b.PUSHKEYS);
b.add(b.LITERAL, "length");
- b.add(b.GET, NO_ARG);
+ b.add(b.GET);
consume(RP);
- ByteCode b2 = new ByteCode(curLine);
+ ForthBlock b2 = new ForthBlock(curLine, sourceName);
b.add(b.SCOPE, b2);
b2.add(b.LITERAL, new Integer(1));
- b2.add(SUB, NO_ARG);
- b2.add(b.DUP, NO_ARG);
+ b2.add(SUB);
+ b2.add(b.DUP);
b2.add(b.LITERAL, new Integer(0));
- b2.add(LT, NO_ARG);
+ b2.add(LT);
b2.add(b.JT, new Integer(7));
- b2.add(b.GET_PRESERVE, NO_ARG);
+ b2.add(b.GET_PRESERVE);
b2.add(b.LITERAL, varName);
b2.add(b.LITERAL, varName);
- b2.add(b.DECLARE, NO_ARG);
- b2.add(b.PUT, NO_ARG);
- b2.add(b.EXPR, parseBlock(false));
+ b2.add(b.DECLARE);
+ b2.add(b.PUT);
+ b2.add(b.EXPR, parseStatement(false));
b2.add(b.LITERAL, null);
return b;
} else {
- ByteCode b2 = new ByteCode(curLine);
+ ForthBlock b2 = new ForthBlock(curLine, sourceName);
b.add(b.SCOPE, b2);
- b2.add(b.EXPR, parseMaximalExpr());
- b2.add(b.POP, NO_ARG);
+
+ e1 = parseMaximalForthBlock();
+ if (e1 == null) e1 = new ForthBlock(curLine, sourceName, b.LITERAL, null);
+
+ b2.add(b.EXPR, e1);
+ b2.add(b.POP);
consume(SEMI);
- ByteCode b3 = new ByteCode(curLine);
+ e2 = parseMaximalForthBlock();
+ consume(SEMI);
+ e3 = parseMaximalForthBlock();
+ consume(RP);
+
+ if (e2 == null) e2 = new ForthBlock(curLine, sourceName, b.LITERAL, null);
+ if (e3 == null) e3 = new ForthBlock(curLine, sourceName, b.LITERAL, null);
+
+ ForthBlock b3 = new ForthBlock(curLine, sourceName);
b2.add(b.LOOP, b3);
b2.add(b.LITERAL, null);
- b3.add(b.EXPR, parseMaximalExpr());
- consume(SEMI);
+ b3.add(b.JT, new Integer(3));
+ b3.add(b.EXPR, e3);
+ b3.add(b.POP);
+ b3.add(b.EXPR, e2);
b3.add(b.JT, new Integer(2));
- b3.add(BREAK, NO_ARG);
- b3.add(b.JT, new Integer(2));
- b3.add(b.EXPR, parseMaximalExpr());
- consume(RP);
- parseBlock(false, b3);
+ b3.add(BREAK);
+ parseStatement(false, b3);
return b;
}
}
}
}
- // Expr //////////////////////////////////////////////////////////////////////
-
- public static final Object NO_ARG = new Object();
-
- class ByteCode extends Expr {
-
- // This class interprets a small forthlike bytecode language
- // we use to represent JavaScript. It's a stack machine.
-
- // Each instruction is an opcode and a literal. Any operation
- // that accesses the top of the stack and does not have a
- // mandatory literal can be performed on a literal instead of
- // the top of the stack.
-
- // opcodes:
- public static final byte arithmetic = -1; // -- arithmetic operators from parser
- public static final byte LITERAL = -2; // < String | Number | null > -- push a literal onto the stack
- public static final byte ARRAY = -3; // < size > -- create a new array of size <size>
- public static final byte OBJECT = -4; // -- push an empty object onto the stack
- public static final byte FUNCTION = -5; // < bytecode_block > -- push a new instance of a function with the given bytecode
- public static final byte DECLARE = -6; // < name > -- declare <name> in the current scope
- public static final byte THIS = -7; // -- push the topmost non-transparent scope onto the stack
- public static final byte GET = -8; // -- get stack[0] from stack[1]
- public static final byte GET_PRESERVE = -80; // -- get stack[0] from stack[1]
- public static final byte PUT = -9; // -- put stack[1] to key stack[0] on stack[2]; leaves object on the stack
- public static final byte JT = -13; // < relative_address > -- pop the stack; if true, jump to <relative_address>
- public static final byte JF = -21; // < relative_address > -- pop the stack; if false, jump to <relative_address>
- public static final byte JMP = -22; // < relative_address > -- jump to <relative_address>
- static public final byte POP = -14; // -- discard the top element on the stack
-
- public static final byte CALL = -15; // < numargs > -- call stack[0] with the topmost <numargs> values as arguments
-
- public static final byte PUSHKEYS = -19; // -- ??
- public static final byte EXPR = -20; // -- transitional
- public static final byte SWAP = -23; // -- transitional
- public static final byte SCOPE = -30; // -- transitional
- public static final byte LOOP = -40; // -- transitional
- public static final byte DUP = -50; // -- transitional
- public static final byte LABEL = -60; // -- transitional
-
- int[] op = new int[10];
- Object[] arg = new Object[10];
- int size = 0;
-
- public ByteCode(int line) { super(line, "foo"); }
- public ByteCode(int line, int op_, Object arg_) { this(line); add(op_, arg_); }
-
- public int size() { return size; }
- public void set(int pos, int op_, Object arg_) { op[pos] = op_; arg[pos] = arg_; }
- public ByteCode add(int op_, Object arg_) {
- if (size == op.length - 1) {
- int[] op2 = new int[op.length * 2]; System.arraycopy(op, 0, op2, 0, op.length); op = op2;
- Object[] arg2 = new Object[op.length * 2]; System.arraycopy(arg, 0, arg2, 0, arg.length); arg = arg2;
- }
- op[size] = op_;
- arg[size] = arg_;
- size++;
- return this;
- }
-
- public Object eval(final JS.Scope s) throws ControlTransferException, JS.Exn {
- return eval(s, new Parser.Thread());
- }
- public Object eval(final JS.Scope s, Parser.Thread t) throws ControlTransferException {
- for(int i=0; i<size; i++)
- switch(op[i]) {
- case LABEL: break; // FIXME
- case LITERAL: t.push(arg[i]); break;
- case OBJECT: t.push(new JS.Obj()); break;
- case ARRAY: t.push(new JS.Array(toNumber(arg[i]).intValue())); break;
- case DECLARE: s.declare(arg[i] == NO_ARG ? (String)t.pop() : (String)arg[i]); break;
- case THIS: t.push(s); break; // FIXME: transparents
- case JT: if (toBoolean(t.pop())) i += toNumber(arg[i]).intValue() - 1; break;
- case JF: if (!toBoolean(t.pop())) i += toNumber(arg[i]).intValue() - 1; break;
- case JMP: i += toNumber(arg[i]).intValue() - 1; break;
- case POP: t.pop(); break;
- case SWAP: t.swap(); break;
- case DUP: t.push(t.peek()); break;
- case NOP: break;
- case EXPR: t.push(((Expr)arg[i]).eval(s)); break;
- case SCOPE: t.push(((ByteCode)arg[i]).eval(new JS.Scope(s), t)); break;
-
- case ASSERT: if (!toBoolean(t.pop())) throw new EvaluatorException("assertion failed"); break;
- case RETURN: throw new ReturnException(t.pop());
- case THROW: throw new JS.Exn(t.pop());
-
- case TRY: break;
- case INSTANCEOF: break;
- case TYPEOF: break;
- case PUSHKEYS: {
- Object o = t.peek();
- Object[] keys = ((JS)o).keys();
- JS.Array a = new JS.Array();
- a.setSize(keys.length);
- for(int j=0; j<keys.length; j++) a.setElementAt(keys[j], j);
- t.push(a);
- break;
- }
-
- case Lexer.BITNOT: t.push(new Long(~toLong(t.pop()))); break;
- case Lexer.BANG: t.push(new Boolean(!toBoolean(t.pop()))); break;
-
- case Lexer.BREAK: {
- // FIXME: make sure this can only appear in proper places
- return Boolean.FALSE;
- }
- case Lexer.CONTINUE: {
- // FIXME: make sure this can only appear in proper places
- return Boolean.TRUE;
- }
- case LOOP: {
- ByteCode loop = (ByteCode)arg[i];
- Parser.Thread t2 = new Parser.Thread();
- t2.push(Boolean.TRUE);
- while (true) {
- Boolean result;
- try {
- result = (Boolean)loop.eval(new JS.Scope(s), t2);
- } catch (ContinueException c) {
- result = Boolean.TRUE;
- } catch (BreakException b) {
- result = Boolean.FALSE;
- }
- if (result == Boolean.FALSE) break;
- t2 = new Parser.Thread();
- t2.push(Boolean.FALSE);
- }
- break;
- }
-
- case PUT: {
- Object val = arg[i] == NO_ARG ? t.pop() : arg[i];
- Object key = t.pop();
- ((JS)t.peek()).put(key, val);
- t.push(val);
- break;
- }
-
- case GET: {
- Object v = arg[i] == NO_ARG ? t.pop() : arg[i];
- Object o = t.pop();
- t.push(doGet(o, v));
- break;
- }
-
- case GET_PRESERVE: {
- Object v = t.pop();
- Object o = t.peek();
- t.push(v);
- t.push(doGet(o, v));
- break;
- }
-
- case CALL: {
- JS.Array arguments = new JS.Array();
- int numArgs = toNumber(arg[i]).intValue();
- arguments.setSize(numArgs);
- for(int j=numArgs - 1; j >= 0; j--) arguments.setElementAt(t.pop(), j);
- JS.Function f = (JS.Function)t.pop();
- if (f == null) throw new JS.Exn(new EvaluatorException("attempted to call null"));
- t.push(f.call(arguments));
- break;
- }
-
- case FUNCTION: {
- final ByteCode myBytes = (ByteCode)arg[i];
- t.push(new JS.Function() {
- public String toString() { return sourceName + ":" + line; }
- public String getSourceName() throws JS.Exn { return sourceName; }
- public Object _call(final JS.Array args) throws JS.Exn {
- Function save = JS.getCurrentFunction();
- JS.currentFunction.put(java.lang.Thread.currentThread(), this);
- JS.Scope scope = new JS.Scope(s) {
- // FIXME
- public String getSourceName() { return sourceName; }
- public Object get(Object key) throws JS.Exn {
- if (key.equals("trapee")) return org.xwt.Trap.currentTrapee();
- else if (key.equals("cascade")) return org.xwt.Trap.cascadeFunction;
- return super.get(key);
- }
- };
- Parser.Thread t0 = new Parser.Thread();
- t0.push(args);
- try {
- return myBytes.eval(scope, t0);
- } catch (ReturnException r) {
- return r.retval;
- } catch (ControlTransferException c) {
- throw new EvaluatorException("error, ControlTransferException tried to leave a function: " + c);
- } finally {
- if (save == null) JS.currentFunction.remove(java.lang.Thread.currentThread());
- else JS.currentFunction.put(java.lang.Thread.currentThread(), save);
- }
- }
- });
- break;
- }
-
- case Lexer.INC: case Lexer.DEC: {
- boolean isPrefix = toBoolean(arg[i]);
- Object key = t.pop();
- JS obj = (JS)t.pop();
- Number num = toNumber(obj.get(key));
- Number val = new Double(op[i] == Lexer.INC ? num.doubleValue() + 1.0 : num.doubleValue() - 1.0);
- obj.put(key, val);
- t.push(isPrefix ? val : num);
- break;
- }
-
- default: {
- Object right = t.pop();
- Object left = t.pop();
- switch(op[i]) {
-
- case Lexer.BITOR: t.push(new Long(toLong(left) | toLong(right))); break;
- case Lexer.BITXOR: t.push(new Long(toLong(left) ^ toLong(right))); break;
- case Lexer.BITAND: t.push(new Long(toLong(left) & toLong(right))); break;
-
- case Lexer.ADD: {
- Object l = left;
- Object r = right;
- if (l instanceof String || r instanceof String) {
- if (l == null) l = "null";
- if (r == null) r = "null";
- if (l instanceof Number && ((Number)l).doubleValue() == ((Number)l).longValue())
- l = new Long(((Number)l).longValue());
- if (r instanceof Number && ((Number)r).doubleValue() == ((Number)r).longValue())
- r = new Long(((Number)r).longValue());
- t.push(l.toString() + r.toString()); break;
- }
- t.push(new Double(toDouble(l) + toDouble(r))); break;
- }
-
- case Lexer.SUB: t.push(new Double(toDouble(left) - toDouble(right))); break;
- case Lexer.MUL: t.push(new Double(toDouble(left) * toDouble(right))); break;
- case Lexer.DIV: t.push(new Double(toDouble(left) / toDouble(right))); break;
- case Lexer.MOD: t.push(new Double(toDouble(left) % toDouble(right))); break;
-
- case Lexer.LSH: t.push(new Long(toLong(left) << toLong(right))); break;
- case Lexer.RSH: t.push(new Long(toLong(left) >> toLong(right))); break;
- case Lexer.URSH: t.push(new Long(toLong(left) >>> toLong(right))); break;
-
- // FIXME: these need to work on strings
- case Lexer.LT: t.push(toDouble(left) < toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
- case Lexer.LE: t.push(toDouble(left) <= toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
- case Lexer.GT: t.push(toDouble(left) > toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
- case Lexer.GE: t.push(toDouble(left) >= toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
-
- case Lexer.EQ:
- case Lexer.NE: {
- // FIXME: should use Javascript coercion-equality rules
- Object l = left;
- Object r = right;
- boolean ret;
- if (l == null) { Object tmp = r; r = l; l = tmp; }
- if (l == null && r == null) ret = true;
- else if (l instanceof Boolean) ret = new Boolean(toBoolean(r)).equals(l);
- else if (l instanceof Number) ret = toNumber(r).doubleValue() == toNumber(l).doubleValue();
- else if (l instanceof String) ret = r != null && l.equals(r.toString());
- else ret = l.equals(r);
- t.push(new Boolean(op[i] == Lexer.EQ ? ret : !ret)); break;
- }
-
- default: throw new Error("unknown opcode " + op[i]);
- } }
- }
- if (t.size() != 1) {
- throw new EvaluatorException("eval() terminated with " + t.size() + " elements on the stack; one expected");
- }
- return t.pop();
- }
-
- public Object doGet(final Object o, final Object v) {
- if (o == null) throw new EvaluatorException("tried to get property \"" + v + "\" from the null value");
- if (o instanceof String) {
- if (v.equals("length")) return new Integer(((String)o).length());
- else if (v.equals("substring")) return new JS.Function() {
- public Object _call(JS.Array args) {
- if (args.length() == 1) return ((String)o).substring(toNumber(args.elementAt(0)).intValue());
- else if (args.length() == 2) return ((String)o).substring(toNumber(args.elementAt(0)).intValue(),
- toNumber(args.elementAt(1)).intValue());
- else throw new Error("String.substring() can only take one or two arguments");
- }
- };
- else if (v.equals("toLowerCase")) return new JS.Function() {
- public Object _call(JS.Array args) {
- return ((String)o).toLowerCase();
- } };
- else if (v.equals("toUpperCase")) return new JS.Function() {
- public Object _call(JS.Array args) {
- return ((String)o).toString().toUpperCase();
- } };
- else if (v.equals("charAt")) return new JS.Function() {
- public Object _call(JS.Array args) {
- return ((String)o).charAt(toNumber(args.elementAt(0)).intValue()) + "";
- } };
- else if (v.equals("lastIndexOf")) return new JS.Function() {
- public Object _call(JS.Array args) {
- if (args.length() != 1) return null;
- return new Integer(((String)o).lastIndexOf(args.elementAt(0).toString()));
- } };
- else if (v.equals("indexOf")) return new JS.Function() {
- public Object _call(JS.Array args) {
- if (args.length() != 1) return null;
- return new Integer(((String)o).indexOf(args.elementAt(0).toString()));
- } };
- throw new Error("Not Implemented: propery " + v + " on String objects");
- } else if (o instanceof Boolean) {
- throw new Error("Not Implemented: properties on Boolean objects");
- } else if (o instanceof Number) {
- Log.log(this, "Not Implemented: properties on Number objects");
- return null;
- //throw new Error("Not Implemented: properties on Number objects");
- } else if (o instanceof JS) {
- return ((JS)o).get(v);
- }
- return null;
- }
- }
-
- class Thread {
- public Object[] os = new Object[256];
- private int size = 0;
- public void push(Object o) {
- os[size++] = o;
- }
- public Object pop() { return os[--size]; }
- public Object peek() { return os[size - 1]; }
- public void swap() { Object temp = os[size - 1]; os[size - 1] = os[size - 2]; os[size - 2] = temp; }
- public int size() { return size; }
- }
-
- class ExprList extends Expr {
- Vec v = new Vec();
- public ExprList(int curLine, int code) { super(curLine, code); }
- public void add(Expr e) { v.addElement(e); }
- public int numExprs() { return v.size(); }
- public int size() { return v.size(); }
- public Expr elementAt(int i) { return (Expr)v.elementAt(i); }
- public Object eval(final JS.Scope s) throws ControlTransferException, JS.Exn {
- switch(code) {
- case LC: {
- // Block
- JS.Scope scope = new JS.Scope(s);
- for(int i=0; i<v.size(); i++) ((Expr)v.elementAt(i)).eval(scope);
- return null;
- }
- case Lexer.LB: {
- // Array ctor
- JS.Array ret = new JS.Array();
- for(int i=0; i<numExprs(); i++) ret.addElement(elementAt(i).eval(s));
- return ret;
- }
- case Lexer.RC: {
- // Object ctor
- JS.Obj ret = new JS.Obj();
- for(int i=0; i<numExprs(); i++) {
- Expr e = elementAt(i);
- Object key = e.left.string;
- Object val = e.right.eval(s);
- ret.put(key, val);
- }
- return ret;
- }
- case Lexer.WHILE:
- case Lexer.DO:
- try {
- boolean first = true;
- Object bogus = null;
- ExprList list = this;
- Expr whileExpr = list.elementAt(0);
- Expr bodyExpr = list.elementAt(1);
- Expr incExpr = list.elementAt(2);
- for(;(first && code == Lexer.DO) || toBoolean(whileExpr.eval(s)); bogus = incExpr.eval(s)) {
- first = false;
- try {
- bodyExpr.eval(s);
- } catch (ContinueException c) {
- if (c.label == null || c.label.equals(string)) continue;
- } catch (BreakException b) {
- if (b.label == null || b.label.equals(string)) return null;
- throw (BreakException)b.fillInStackTrace();
- }
- }
- } catch (BreakException e) {
- if (e.label != null && !e.label.equals(string)) throw e;
- }
- return null;
- case Lexer.VAR:
- for(int i=0; i<size(); i++) {
- Expr e = elementAt(i);
- s.declare(e.left.string);
- if (e.right != null) e.right.eval(s);
- }
- return null;
- default: throw new Error("augh!");
- }
- }
- }
-
/** a block is either a single statement or a list of statements surrounded by curly braces; all expressions are also statements */
- public Expr parseBlock(boolean requireBraces) throws IOException { return parseBlock(requireBraces, null); }
- public Expr parseBlock(boolean requireBraces, ByteCode b) throws IOException {
- Expr smt = null;
+ public ForthBlock parseStatement(boolean requireBraces) throws IOException { return parseStatement(requireBraces, null); }
+ public ForthBlock parseStatement(boolean requireBraces, ForthBlock b) throws IOException {
+ ForthBlock smt = null;
int tok = peekToken();
if (tok == -1) return null;
boolean braced = tok == LC;
if (requireBraces && !braced) throw new ParserException("expected {, got " + codeToString[tok]);
if (braced) consume(LC);
int curLine = line;
- ByteCode ret = new ByteCode(curLine);
- ByteCode block = b == null ? new ByteCode(curLine) : b;
+ ForthBlock ret = new ForthBlock(curLine, sourceName);
+ ForthBlock block = b == null ? new ForthBlock(curLine, sourceName) : b;
block.add(ret.LITERAL, Boolean.TRUE);
ret.add(block.SCOPE, block);
while(true) {
switch(tok = peekToken()) {
- case LC: smt = parseBlock(true); break;
+ case LC: smt = parseStatement(true); break;
case GOTO: throw new ParserException("goto not supported");
case THROW: case RETURN: case ASSERT: {
getToken();
- ByteCode r = new ByteCode(curLine);
+ ForthBlock r = new ForthBlock(curLine, sourceName);
if (tok == RETURN && peekToken() == SEMI) r.add(b.LITERAL, null);
- else r.add(b.EXPR, parseMaximalExpr());
+ else r.add(b.EXPR, parseMaximalForthBlock());
consume(SEMI);
- r.add(tok, NO_ARG);
+ r.add(tok);
smt = r;
break;
}
case BREAK: case CONTINUE: {
getToken();
if (peekToken() == NAME) consume(NAME);
- smt = new ByteCode(curLine, tok, string);
+ smt = new ForthBlock(curLine, sourceName, tok, string);
consume(SEMI);
break;
}
consume(NAME);
if (peekToken() == COLON) {
consume(COLON);
- smt = new ByteCode(curLine, ByteCode.LABEL, string);
+ smt = new ForthBlock(curLine, sourceName, ForthBlock.LABEL, string);
break;
} else {
pushBackToken(NAME, name);
case -1:
default:
- smt = parseMaximalExpr();
+ smt = parseMaximalForthBlock();
if (smt == null) return block.size() == 0 ? null : ret;
if (peekToken() == SEMI) getToken();
break;
if (!braced) return smt;
block.add(block.EXPR, smt);
- block.add(block.POP, NO_ARG);
+ block.add(block.POP);
}
}
-
- /** sorta like gcc trees */
- class Expr {
- int code = -1;
-
- final Expr left;
- final Expr right;
- int line = -1;
- String sourceName = "unknown";
-
- String string = null;
- Number number = null;
-
- public String toString() { return toString(0); }
- public String toString(int indent) {
- String ret = "";
- for(int i=0; i<indent; i++) ret += " ";
- ret += Lexer.codeToString[code];
- if (code == Lexer.NUMBER) ret += " " + number;
- else if (string != null) ret += " \"" + string + "\"";
- ret += "\n";
- if (left != null) ret += left.toString(indent + 2);
- if (right != null) ret += right.toString(indent + 2);
- return ret;
- }
-
- public Expr(int line, String s) { this(line, Lexer.STRING); this.string = s; } // an identifier or label
- public Expr(int line, int code, String s) { this(line, code); this.string = s; }
- public Expr(int line, Number n) { this(line, Lexer.NUMBER); this.number = n; } // an identifier or label
- public Expr(int line, int code) { this(line, code, null, null); }
- public Expr(int line, int code, Expr left) { this(line, code, left, null); }
- public Expr(int line, int code, Expr left, Expr right) {
- this.code = code; this.left = left; this.right = right;
- this.line = line;
- this.sourceName = Parser.this.sourceName;
- }
-
- public double toDouble(Object o) { return toNumber(o).doubleValue(); }
- public long toLong(Object o) { return toNumber(o).longValue(); }
- public boolean toBoolean(Object o) {
- if (o == null) return false;
- if (o instanceof Boolean) return ((Boolean)o).booleanValue();
- if (o instanceof Number) return o.equals(new Integer(0));
- return true;
- }
-
- public Object eval(final JS.Scope s) throws ControlTransferException, JS.Exn {
- switch(code) {
-
- case Lexer.NULL: return null;
- case Lexer.TYPEOF: {
- Object o = left.eval(s);
- if (o == null) return "null";
- if (o.getClass() == String.class) return "string";
- if (o.getClass() == Boolean.class) return "boolean";
- if (o instanceof Number) return "number";
- if (o instanceof JS.Array) return "array";
- if (o instanceof JS) return "object";
- throw new EvaluatorException("typeof " + o.getClass().getName() + " unknown");
- }
-
- case Lexer.TRY: {
- boolean safeToExit = false;
- try {
- Object ret = left.eval(s);
- safeToExit = true;
- return ret;
- } catch (JS.Exn e) {
- ExprList list = (ExprList)right;
- Expr c = list.elementAt(0);
- if (c.code == Lexer.CATCH) {
- JS.Scope scope = new JS.Scope(s);
- s.put(c.left.string, e);
- c.right.eval(scope);
- c = list.elementAt(1);
- }
- if (c.code == Lexer.FINALLY) {
- JS.Scope scope = new JS.Scope(s);
- c.left.eval(scope);
- }
- } finally {
- if (!safeToExit) Log.log(this, "WARNING: Java exception penetrated a JavaScript try{} block");
- }
- return null;
- }
-
- case Lexer.FOR:
- Object[] keys = ((JS)left.right.eval(s)).keys();
- for(int i=0; i<keys.length; i++) {
- JS.Scope scope = new JS.Scope(s);
- scope.declare(left.string);
- scope.put(left.string, keys[i]);
- try {
- right.eval(scope);
- } catch (ContinueException c) {
- if (c.label == null || c.label.equals(string)) continue;
- } catch (BreakException b) {
- if (b.label == null || b.label.equals(string)) return null;
- throw (BreakException)b.fillInStackTrace();
- }
- }
- return null;
-
- default: throw new EvaluatorException("don't know how to eval an Expr with code " + Lexer.codeToString[code] + "\n" + this);
- }
- }
-
- class EvaluatorException extends RuntimeException {
- public EvaluatorException(String s) { super(sourceName + ":" + line + " " + s); }
- }
- }
-
- static abstract class ControlTransferException extends Exception { }
- static class BreakException extends ControlTransferException {
- public String label;
- BreakException(String label) { this.label = label; }
- }
- static class ContinueException extends ControlTransferException {
- public String label;
- ContinueException(String label) { this.label = label; }
- }
- static class ReturnException extends ControlTransferException {
- public Object retval;
- ReturnException(Object retval) { this.retval = retval; }
- }
-
class ParserException extends RuntimeException {
public ParserException(String s) { super(sourceName + ":" + line + " " + s); }
}
-
- public static Number toNumber(Object o) {
- if (o == null) return new Long(0);
- if (o instanceof Number) return ((Number)o);
- if (o instanceof String) try { return new Double((String)o); } catch (NumberFormatException e) { return new Double(0); }
- if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? new Long(1) : new Long(0);
- if (o instanceof JS) return ((JS)o).coerceToNumber();
- // FIXME
- throw new Error("toNumber() got object of type " + o.getClass().getName());
- }
- }
+
+}
projects / org.ibex.core.git / commitdiff