X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=0191a59b8e5af97f7caad74deeb02c8abe8df400;hb=62b09c2447b9516863916b076fe64fe98ec1670f;hp=0a949e38c0d097e569aaa66c7b09c1a8d1e5b9be;hpb=395d61dea4f5f7b22120e8b0b3fd9b75351c0a98;p=org.ibex.core.git diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java index 0a949e3..0191a59 100644 --- a/src/org/xwt/js/JS.java +++ b/src/org/xwt/js/JS.java @@ -1,95 +1,224 @@ -// 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 org.xwt.*; +import java.io.*; +import java.util.*; -/** The public API for the JS engine */ -// FEATURE: try using mutable, recycled 'Num' objects -public interface JS { - - public abstract Object get(Object key) throws JS.Exn; - public abstract void put(Object key, Object val) throws JS.Exn; - public abstract Object[] enumerateProperties(); - - public abstract Number coerceToNumber() throws JS.Exn; - public abstract boolean coerceToBoolean() throws JS.Exn; - public abstract String coerceToString() throws JS.Exn; - - public static class Obj implements JS { - private Hash entries; - public Obj() { } - public Object get(Object key) { return entries.get(key); } - public void put(Object key, Object val) { entries.put(key, val); } - public Object[] enumerateProperties() { return(entries.keys()); } - public Number coerceToNumber() { throw new Error("tried to turn a Object into a Number"); } - public String coerceToString() { throw new Error("tried to turn a Object into a String"); } - public boolean coerceToBoolean() { throw new Error("tried to turn a Object into a Boolean"); } - } - - public static class Array extends Obj { - private Vec vec = new Vec(); - private static int intVal(Object o) { - if (o instanceof Number) { - int intVal = ((Number)o).intValue(); - if (intVal == ((Number)o).doubleValue()) return intVal; - return Integer.MIN_VALUE; - } - if (!(o instanceof String)) return Integer.MIN_VALUE; - String s = (String)o; - for(int i=0; i '9') return Integer.MIN_VALUE; - return Integer.parseInt(s); - } - public Object get(Object key) { - if (key.equals("length")) return new Long(vec.size()); - int i = intVal(key); - if (i == Integer.MIN_VALUE) return super.get(key); - return vec.elementAt(i); - } - public void put(Object key, Object val) { - if (key.equals("length")) vec.setSize(Expr.toNumber(val).intValue()); - int i = intVal(key); - if (i == Integer.MIN_VALUE) super.put(key, val); - else vec.setElementAt(val, i); - } - public Object[] enumerateProperties() { return null; } // FIXME - void addElement(Object o) { vec.addElement(o); } - } - - public static interface Function extends JS { - public abstract Object call(JS.Array args) throws JS.Exn; // FEATURE: try to recycle these arrays? - public abstract Scope getParentScopeOfDeclaration(); - } - - public static abstract class ObjFunction extends Obj implements Function { } - - /** if JS calls a Java method, and the Java method throws an exception, it can only be caught by JS if it is a subclass of Exn. */ - public static class Exn extends RuntimeException { - private Object js = null; - public Exn(Object js) { this.js = js; } - public Object getObject() { return js; } - } +/** The minimum set of functionality required for objects which are manipulated by JavaScript */ +public class JS extends org.xwt.util.BalancedTree { + + // Static Interpreter Control Methods /////////////////////////////////////////////////////////////// + + /** log a message with the current JavaScript sourceName/line */ + public static void log(Object o, Object message) { logJS(message); } + public static void log(Object message) { Log.echo(JS.getSourceName() + ":" + JS.getLine(), message); } + + public static int getLine() { + Interpreter c = Interpreter.current(); + return c == null || c.f == null || c.pc < 0 || c.pc >= c.f.size ? -1 : c.f.line[c.pc]; + } - /** Any object which becomes part of the scope chain must support this interface */ - public static class Scope extends Obj { - private Scope parentScope; - private static Object NULL = new Object(); - public Scope(Scope parentScope) { this.parentScope = parentScope; } - public JS getParentScope() { return parentScope; } - public boolean has(Object key) { return super.get(key) != null; } - public Object get(Object key) { - if (!has(key)) return getParentScope().get(key); - Object ret = super.get(key); return ret == NULL ? null : ret; - } - public void put(Object key, Object val) { - if (!has(key)) getParentScope().put(key, val); - else super.put(key, val == null ? NULL : val); - } - public Object[] enumerateProperties() { throw new Error("you can't enumerate the properties of a Scope"); } - public void declare(String s) { super.put(s, NULL); } + public static String getSourceName() { + Interpreter c = Interpreter.current(); + return c == null || c.f == null ? null : c.f.sourceName; } + + public static class NotPauseableException extends Exception { NotPauseableException() { } } + + /** returns a callback which will restart the context; expects a value to be pushed onto the stack when unpaused */ + public static UnpauseCallback pause() throws NotPauseableException { + Interpreter i = Interpreter.current(); + if (i.pausecount == -1) throw new NotPauseableException(); + i.pausecount++; + return new JS.UnpauseCallback(i); + } + + public static class UnpauseCallback implements Scheduler.Task { + Interpreter i; + UnpauseCallback(Interpreter i) { this.i = i; } + public void perform() throws JSExn { unpause(null); } + public void unpause(Object o) throws JSExn { + // FIXME: if o instanceof JSExn, throw it into the JSworld + i.stack.push(o); + i.resume(); + } + } + + + + // Static Helper Methods /////////////////////////////////////////////////////////////////////////////////// + + /** coerce an object to a Boolean */ + public static boolean toBoolean(Object o) { + if (o == null) return false; + if (o instanceof Boolean) return ((Boolean)o).booleanValue(); + if (o instanceof Long) return ((Long)o).longValue() != 0; + if (o instanceof Integer) return ((Integer)o).intValue() != 0; + if (o instanceof Number) { + double d = ((Number) o).doubleValue(); + // NOTE: d == d is a test for NaN. It should be faster than Double.isNaN() + return d != 0.0 && d == d; + } + if (o instanceof String) return ((String)o).length() != 0; + return true; + } + + /** coerce an object to a Long */ + public static long toLong(Object o) { return toNumber(o).longValue(); } + + /** coerce an object to an Int */ + public static int toInt(Object o) { return toNumber(o).intValue(); } + + /** coerce an object to a Double */ + public static double toDouble(Object o) { return toNumber(o).doubleValue(); } + + /** coerce an object to a Number */ + public static Number toNumber(Object o) { + if (o == null) return ZERO; + if (o instanceof Number) return ((Number)o); + + // NOTE: There are about 3 pages of rules in ecma262 about string to number conversions + // We aren't even close to following all those rules. We probably never will be. + if (o instanceof String) + try { return N((String)o); } catch (NumberFormatException e) { return N(Double.NaN); } + if (o instanceof Boolean) return ((Boolean)o).booleanValue() ? N(1) : ZERO; + if (o instanceof JS) return ((JS)o).coerceToNumber(); + throw new Error("toNumber() got object of type " + o.getClass().getName() + " which we don't know how to handle"); + } + + /** coerce an object to a String */ + public static String toString(Object o) { + if(o == null) return "null"; + if(o instanceof String) return (String) o; + if(o instanceof Integer || o instanceof Long || o instanceof Boolean) return o.toString(); + if(o instanceof JS) return ((JS)o).coerceToString(); + if(o instanceof Double || o instanceof Float) { + double d = ((Number)o).doubleValue(); + if((int)d == d) return Integer.toString((int)d); + return o.toString(); + } + return o.toString(); + } + + + // Instance Methods //////////////////////////////////////////////////////////////////// + + public static final Integer ZERO = new Integer(0); -} + // this gets around a wierd fluke in the Java type checking rules for ?..: + public static final Object T = Boolean.TRUE; + public static final Object F = Boolean.FALSE; + + public static final Boolean B(boolean b) { return b ? Boolean.TRUE : Boolean.FALSE; } + public static final Boolean B(int i) { return i==0 ? Boolean.FALSE : Boolean.TRUE; } + public static final Number N(String s) { return s.indexOf('.') == -1 ? N(Integer.parseInt(s)) : new Double(s); } + public static final Number N(double d) { return (int)d == d ? N((int)d) : new Double(d); } + public static final Number N(long l) { return N((int)l); } + + private static final Integer[] smallIntCache = new Integer[65535 / 4]; + private static final Integer[] largeIntCache = new Integer[65535 / 4]; + public static final Number N(int i) { + Integer ret = null; + int idx = i + smallIntCache.length / 2; + if (idx < smallIntCache.length && idx > 0) { + ret = smallIntCache[idx]; + if (ret != null) return ret; + } + else ret = largeIntCache[Math.abs(idx % largeIntCache.length)]; + if (ret == null || ret.intValue() != i) { + ret = new Integer(i); + if (idx < smallIntCache.length && idx > 0) smallIntCache[idx] = ret; + else largeIntCache[Math.abs(idx % largeIntCache.length)] = ret; + } + return ret; + } + + private static Enumeration emptyEnumeration = new Enumeration() { + public boolean hasMoreElements() { return false; } + public Object nextElement() { throw new NoSuchElementException(); } + }; + + private Hash entries = null; + public Enumeration keys() throws JSExn { + return entries == null ? emptyEnumeration : entries.keys(); + } + public Object get(Object key) throws JSExn { return entries == null ? null : entries.get(key, null); } + public void put(Object key, Object val) throws JSExn { + if (entries == null) entries = new Hash(); + entries.put(key, null, val); + } + + // Trap support ////////////////////////////////////////////////////////////////////////////// + /** override and return true to allow placing traps on this object. + * if isRead true, this is a read trap, otherwise write trap + **/ + protected boolean isTrappable(Object name, boolean isRead) { return false; } + /** performs a put, triggering traps if present; traps are run in an unpauseable interpreter */ + public void putAndTriggerTraps(Object key, Object value) throws JSExn { + Trap t = getTrap(key); + if (t != null) t.invoke(value); + else put(key, value); + } + + /** performs a get, triggering traps if present; traps are run in an unpauseable interpreter */ + public Object getAndTriggerTraps(Object key) throws JSExn { + Trap t = getTrap(key); + if (t != null) return t.invoke(); + else return get(key); + } + + /** retrieve a trap from the entries hash */ + protected final Trap getTrap(Object key) { + return entries == null ? null : (Trap)entries.get(key, Trap.class); + } + + /** retrieve a trap from the entries hash */ + protected final void putTrap(Object key, Trap value) { + if (entries == null) entries = new Hash(); + entries.put(key, Trap.class, value); + } + /** adds a trap, avoiding duplicates */ + protected final void addTrap(Object name, JSFunction f) throws JSExn { + if (f.numFormalArgs > 1) throw new JSExn("traps must take either one argument (write) or no arguments (read)"); + boolean isRead = f.numFormalArgs == 0; + if (!isTrappable(name, isRead)) throw new JSExn("not allowed "+(isRead?"read":"write")+" trap on property: "+name); + for(Trap t = getTrap(name); t != null; t = t.next) if (t.f == f) return; + putTrap(name, new Trap(this, name.toString(), f, (Trap)getTrap(name))); + } + + /** deletes a trap, if present */ + protected final void delTrap(Object name, JSFunction f) { + Trap t = (Trap)getTrap(name); + if (t == null) return; + if (t.f == f) { putTrap(t.name, t.next); return; } + for(; t.next != null; t = t.next) if (t.next.f == f) { t.next = t.next.next; return; } + } + + + // Call Support ////////////////////////////////////////////////////////////////////////////// + + // return this from get() if the key was actually a method. + public static final Object METHOD = new Object(); + public Object callMethod(Object method, Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn { + throw new JSExn("attempted to call the null value (method "+method+")"); + } + public Object call(Object a0, Object a1, Object a2, Object[] rest, int nargs) throws JSExn { + throw new JSExn("you cannot call this object (class=" + this.getClass().getName() +")"); + } + + + // Typing Support ////////////////////////////////////////////////////////////////////////////// + + public Number coerceToNumber() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a Number"); } + public String coerceToString() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a String"); } + public boolean coerceToBoolean() { throw new JSRuntimeExn("tried to coerce a JavaScript object to a Boolean"); } + + public String typeName() { return "object"; } + +}