--- /dev/null
+// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
+package org.xwt.js;
+
+import java.io.*;
+import org.xwt.util.*;
+
+/** sorta like gcc trees */
+public class Expr {
+ int code = -1;
+
+ final Expr left;
+ final Expr right;
+ Expr next = null; // if this expr is part of a list
+
+ 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);
+ if (next != null) ret += next.toString(indent);
+ return ret;
+ }
+
+ public Expr(String s) { this(Lexer.STRING); this.string = s; } // an identifier or label
+ public Expr(int code, String s) { this(code); this.string = s; }
+ public Expr(Number n) { this(Lexer.NUMBER); this.number = n; } // an identifier or label
+ public Expr(int code) { this(code, null, null); }
+ public Expr(int code, Expr left) { this(code, left, null); }
+ public Expr(int code, Expr left, Expr right) { this.code = code; this.left = left; this.right = right; }
+
+ public static Number toNumber(Object o) {
+ if (o == null) return new Long(0);
+ if (o instanceof Number) return ((Number)o);
+ if (o instanceof String) return new Double((String)o);
+ if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? new Long(1) : new Long(0);
+ if (o instanceof JS) return ((JS)o).coerceToNumber();
+ throw new Error("toNumber() got object of type " + o.getClass().getName());
+ }
+
+ public static double toDouble(Object o) { return toNumber(o).doubleValue(); }
+ public static long toLong(Object o) { return toNumber(o).longValue(); }
+ public static 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.BITOR: return new Long(toLong(left.eval(s)) | toLong(right.eval(s)));
+ case Lexer.BITXOR: return new Long(toLong(left.eval(s)) ^ toLong(right.eval(s)));
+ case Lexer.BITAND: return new Long(toLong(left.eval(s)) & toLong(right.eval(s)));
+ case Lexer.BITNOT: return new Long(~toLong(left.eval(s)));
+
+ case Lexer.ADD: {
+ Object l = left.eval(s);
+ Object r = right.eval(s);
+ if (l instanceof String || r instanceof String) return l.toString() + r.toString();
+ return new Double(toDouble(l) + toDouble(r));
+ }
+
+ case Lexer.SUB: return new Double(toDouble(left.eval(s)) - toDouble(right.eval(s)));
+ case Lexer.MUL: return new Double(toDouble(left.eval(s)) * toDouble(right.eval(s)));
+ case Lexer.DIV: return new Double(toDouble(left.eval(s)) / toDouble(right.eval(s)));
+ case Lexer.MOD: return new Double(toDouble(left.eval(s)) % toDouble(right.eval(s)));
+
+ case Lexer.LSH: return new Long(toLong(left.eval(s)) << toLong(right.eval(s)));
+ case Lexer.RSH: return new Long(toLong(left.eval(s)) >> toLong(right.eval(s)));
+ case Lexer.URSH: return new Long(toLong(left.eval(s)) >>> toLong(right.eval(s)));
+
+ case Lexer.LT: return toDouble(left.eval(s)) < toDouble(right.eval(s)) ? Boolean.TRUE : Boolean.FALSE;
+ case Lexer.LE: return toDouble(left.eval(s)) <= toDouble(right.eval(s)) ? Boolean.TRUE : Boolean.FALSE;
+ case Lexer.GT: return toDouble(left.eval(s)) > toDouble(right.eval(s)) ? Boolean.TRUE : Boolean.FALSE;
+ case Lexer.GE: return toDouble(left.eval(s)) >= toDouble(right.eval(s)) ? Boolean.TRUE : Boolean.FALSE;
+
+ case Lexer.OR: return new Boolean(toBoolean(left.eval(s)) || toBoolean(right.eval(s)));
+ case Lexer.AND: return new Boolean(toBoolean(left.eval(s)) && toBoolean(right.eval(s)));
+
+ case Lexer.EQ:
+ case Lexer.NE: {
+ // FIXME: should use Javascript coercion-equality rules
+ boolean ret = left.eval(s).equals(right.eval(s));
+ return new Boolean(code == Lexer.EQ ? ret : !ret);
+ }
+
+ case Lexer.INC:
+ case Lexer.DEC:
+ case Lexer.ASSIGN: {
+ Object v = (code == Lexer.ASSIGN) ? right.eval(s) : new Double(toDouble(left.eval(s)) + (code == Lexer.INC ? 1 : -1));
+ if (left.code == Lexer.DOT) {
+ Object o = left.left.eval(s);
+ if (o instanceof String) {
+ throw new Error("can't set properties on a String");
+ } else if (o instanceof Number) {
+ throw new Error("can't set properties on a Number");
+ } else if (o instanceof Boolean) {
+ throw new Error("can't set properties on a Boolean");
+ } else {
+ ((JS)left.left.eval(s)).put(left.right.eval(s), v);
+ return v;
+ }
+ } else {
+ s.put(left.string, v);
+ return v;
+ }
+ }
+
+ 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 Error("typeof " + o.getClass().getName() + " unknown");
+ }
+
+ case Lexer.NUMBER: return number;
+ case Lexer.STRING: return string;
+
+ case Lexer.NULL: return null;
+ case Lexer.THIS: return s;
+ case Lexer.FALSE: return Boolean.FALSE;
+ case Lexer.TRUE: return Boolean.TRUE;
+ case Lexer.ASSERT: if (!toBoolean(left.eval(s))) throw new Error("assertion failed");
+ case Lexer.THROW: throw new JS.Exn(left.eval(s));
+
+ case Lexer.NAME: return s.get(string);
+ case Lexer.DOT: {
+ Object o = left.eval(s);
+ Object v = right.eval(s);
+ if (o instanceof String) {
+ if (v.equals("length")) return new Integer(((String)o).length());
+ throw new Error("Not Implemented: properties on String objects");
+ } else if (o instanceof Boolean) {
+ throw new Error("Not Implemented: properties on Boolean objects");
+ } else if (o instanceof Number) {
+ throw new Error("Not Implemented: properties on Number objects");
+ } else if (o instanceof JS) {
+ return ((JS)o).get(v);
+ }
+ }
+
+ case Lexer.TRY: {
+ boolean safeToExit = false;
+ try {
+ Object ret = left.eval(s);
+ safeToExit = true;
+ return ret;
+ } catch (JS.Exn e) {
+ Expr c = right;
+ if (c.code == Lexer.CATCH) {
+ JS.Scope scope = new JS.Scope(s);
+ s.put(c.left.string, e);
+ c.right.eval(scope);
+ c = c.next;
+ }
+ 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.LP:
+ JS.Function f = (JS.Function)left.eval(s);
+ JS.Array arguments = new JS.Array();
+ for(Expr e = right; e != null; e = e.next) arguments.addElement(e.eval(s));
+ return f.call(arguments);
+
+ case Lexer.FUNCTION:
+ return new JS.ObjFunction() {
+ public JS.Scope getParentScopeOfDeclaration() { return s; }
+ public Object call(JS.Array args) throws JS.Exn {
+ JS.Scope scope = new JS.Scope(getParentScopeOfDeclaration()) {
+ public Object get(Object key) throws JS.Exn {
+ if (key.equals("trapee")) return org.xwt.Trap.currentTrapee();
+ return super.get(key);
+ }
+ }
+ // FIXME
+ args.put("cascade", org.xwt.Trap.cascadeFunction);
+ scope.put("arguments", args);
+ int i = 0;
+ for(Expr e = left; e != null; e = e.next) scope.put(e.string, args.get(new Integer(i++)));
+ try {
+ return right.eval(scope);
+ } catch (ReturnException r) {
+ return r.retval;
+ } catch (ControlTransferException c) {
+ throw new Error("error, ControlTransferException tried to leave a function: " + c);
+ }
+ }
+ };
+
+ case Lexer.FOR:
+ Object[] keys = ((JS)left.right.eval(s)).enumerateProperties();
+ try {
+ for(int i=0; i<keys.length; i++) {
+ JS.Scope scope = new JS.Scope(s);
+ scope.put(left.left.string, keys[i]);
+ try {
+ right.eval(scope);
+ } catch (ContinueException c) { /* FIXME: handle labels */ }
+ }
+ } catch (BreakException b) { /* FIXME: handle labels */ }
+ return null;
+
+ case Lexer.SWITCH:
+ Object switchVal = left.eval(s);
+ boolean go = false;
+ try {
+ for(Expr e = right; e != null; e = e.next) {
+ if (go || e.code == Lexer.DEFAULT || e.left.eval(s).equals(switchVal)) go = true;
+ if (go) e.right.eval(s);
+ }
+ } catch (BreakException b) { /* FIXME: handle labels */ }
+ return null;
+
+ case Lexer.LB: {
+ JS.Array ret = new JS.Array();
+ for(Expr e = left; e != null; e = e.next) ret.addElement(e.eval(s));
+ return ret;
+ }
+
+ case Lexer.LC: // block
+ for(Expr e = left; e != null; e = e.next) e.eval(s);
+ return null;
+
+ case Lexer.RC: { // Object ctor
+ JS.Obj ret = new JS.Obj();
+ for(Expr e = left; e != null; e = e.next)
+ ret.put(e.left.string, e.right.eval(s));
+ return ret;
+ }
+
+ case Lexer.VAR:
+ for(Expr e = left; e != null; e = e.next)
+ if (e.code == Lexer.NAME) {
+ s.declare(e.string);
+ } else {
+ s.declare(e.left.string);
+ e.eval(s);
+ }
+ return null;
+
+ case Lexer.HOOK: return toBoolean(left.eval(s)) ? right.left.eval(s) : right.right.eval(s);
+ case Lexer.IF: return toBoolean(left.eval(s)) ? right.left.eval(s) : right.right.eval(s);
+
+ case Lexer.BREAK: throw new BreakException(string);
+ case Lexer.CONTINUE: throw new ContinueException(string);
+ case Lexer.RETURN: throw new ReturnException(left == null ? null : left.eval(s));
+
+ case Lexer.WHILE:
+ case Lexer.DO:
+ try {
+ boolean first = true;
+ while((first && code == Lexer.DO) || toBoolean(left.eval(s))) {
+ first = false;
+ try { right.eval(s); }
+ catch (ContinueException e) {
+ if (e.label != null && !e.label.equals(string)) throw e;
+ }
+ }
+ } catch (BreakException e) {
+ if (e.label != null && !e.label.equals(string)) throw e;
+ }
+ return null;
+
+ default: throw new Error("don't know how to eval an Expr with code " + Lexer.codeToString[code]);
+ }
+ }
+
+ private static abstract class ControlTransferException extends Exception { }
+ private static class BreakException extends ControlTransferException {
+ public String label;
+ BreakException(String label) { this.label = label; }
+ }
+ private static class ContinueException extends ControlTransferException {
+ public String label;
+ ContinueException(String label) { this.label = label; }
+ }
+ private static class ReturnException extends ControlTransferException {
+ public Object retval;
+ ReturnException(Object retval) { this.retval = retval; }
+ }
+}
+
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