-// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
+// Copyright 2003 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 OpCodes, Tokens {
+/**
+ * A block of JavaScript bytecode.
+ *
+ * The JavaScript ByteCode runs on a very simple stack machine.
+ */
+class ByteCodeBlock implements ByteCodes, Tokens {
int line;
String sourceName;
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 ByteCodeBlock(int line, String sourceName) { this.line = line; this.sourceName = sourceName; }
+ public ByteCodeBlock(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 void paste(ForthBlock other) { for(int i=0; i<other.size; i++) add(other.op[i], other.arg[i]); }
- public ForthBlock add(int op_) { return add(op_, null); }
- public ForthBlock add(int op_, Object arg_) {
+ public void paste(ByteCodeBlock other) { for(int i=0; i<other.size; i++) add(other.op[i], other.arg[i]); }
+ public ByteCodeBlock add(int op_) { return add(op_, null); }
+ public ByteCodeBlock 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;
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
+ public Object eval(final JS.Scope s) throws ControlTransferException, JS.Exn { return eval(s, new Vec()); }
+ public Object eval(final JS.Scope s, Vec t) throws ControlTransferException {
+ for(int i=0; i<size; i++) switch(op[i]) {
+ case LABEL: break;
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 TOPSCOPE: t.push(s); break;
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 SWAP: { Object o1 = t.pop(); Object o2 = t.pop(); t.push(o1); t.push(o2); 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))); break;
-
+ case SCOPE: t.push(((ByteCodeBlock)arg[i]).eval(new JS.Scope(s))); 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 BITNOT: t.push(new Long(~JS.toLong(t.pop()))); break;
+ case BANG: t.push(new Boolean(!JS.toBoolean(t.pop()))); break;
+ case BREAK: return Boolean.FALSE;
+ case CONTINUE: return Boolean.TRUE;
+
case PUSHKEYS: {
Object o = t.peek();
Object[] keys = ((JS)o).keys();
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);
+ ByteCodeBlock loop = (ByteCodeBlock)arg[i];
+ Vec stack2 = new Vec();
+ stack2.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;
- }
+ try { result = (Boolean)loop.eval(new JS.Scope(s), stack2);
+ } catch (ContinueException c) { result = Boolean.TRUE;
+ } catch (BreakException b) { result = Boolean.FALSE; }
if (result == Boolean.FALSE) break;
- t2 = new Stack();
- t2.push(Boolean.FALSE);
+ stack2 = new Vec();
+ stack2.push(Boolean.FALSE);
}
break;
}
break;
}
- case OpCodes.FUNCTION: {
- final ForthBlock myBytes = (ForthBlock)arg[i];
+ case NEWFUNCTION: {
+ final ByteCodeBlock myBytes = (ByteCodeBlock)arg[i];
t.push(new JS.Function() {
- public String toString() { return sourceName + ":" + line; }
public String getSourceName() throws JS.Exn { return sourceName; }
public int getLine() throws JS.Exn { return line; }
- public Object _call(final JS.Array args) throws JS.Exn {
- Function save = JS.getCurrentFunction();
- JS.currentFunction.put(java.lang.Thread.currentThread(), this);
+ public Object _call(final JS.Array args) throws JS.Exn, ControlTransferException {
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();
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);
- }
+ Vec stack = new Vec();
+ stack.push(args);
+ return myBytes.eval(scope, stack);
}
});
break;
}
- case Lexer.INC: case Lexer.DEC: {
+ case INC: case 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);
+ Number val = new Double(op[i] == INC ? num.doubleValue() + 1.0 : num.doubleValue() - 1.0);
obj.put(key, val);
t.push(isPrefix ? val : num);
break;
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 BITOR: t.push(new Long(JS.toLong(left) | JS.toLong(right))); break;
+ case BITXOR: t.push(new Long(JS.toLong(left) ^ JS.toLong(right))); break;
+ case BITAND: t.push(new Long(JS.toLong(left) & JS.toLong(right))); break;
- case Lexer.ADD: {
+ case ADD: {
Object l = left;
Object r = right;
if (l instanceof String || r instanceof String) {
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 SUB: t.push(new Double(JS.toDouble(left) - JS.toDouble(right))); break;
+ case MUL: t.push(new Double(JS.toDouble(left) * JS.toDouble(right))); break;
+ case DIV: t.push(new Double(JS.toDouble(left) / JS.toDouble(right))); break;
+ case 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;
+ case LSH: t.push(new Long(JS.toLong(left) << JS.toLong(right))); break;
+ case RSH: t.push(new Long(JS.toLong(left) >> JS.toLong(right))); break;
+ case 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 LT: t.push(JS.toDouble(left) < JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
+ case LE: t.push(JS.toDouble(left) <= JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
+ case GT: t.push(JS.toDouble(left) > JS.toDouble(right) ? Boolean.TRUE : Boolean.FALSE); break;
+ case 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
+ case EQ:
+ case NE: {
Object l = left;
Object r = right;
boolean ret;
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;
+ t.push(new Boolean(op[i] == EQ ? ret : !ret)); break;
}
default: throw new Error("unknown opcode " + op[i]);
} }
}
- if (t.size() != 1) {
- for(int i=0; i<size; i++) {
- System.out.println((op[i] >= 0 ? codeToString[op[i]] : "" + op[i]) + " [" + arg[i] + "]");
- }
- throw new EvaluatorException(line, sourceName, "eval() terminated with " + t.size() + " elements on the stack; one expected");
- }
+ 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) {
+ 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() {
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); }
+ public EvaluatorException(int line, String sourceName, String s) {
+ super(sourceName + ":" + line + " " + s);
+ }
}
- static abstract class ControlTransferException extends Exception { }
+ static abstract class ControlTransferException extends RuntimeException { }
static class BreakException extends ControlTransferException {
public String label;
BreakException(String label) { this.label = label; }
projects / org.ibex.core.git / blobdiff