X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=327d35c4875523188324556b26a32776d02d1bd6;hb=8c1756ef3fd42cc2f324baf47e13a83f51045efe;hp=1da4c548abe137429462280eb0a448f5246f8a95;hpb=ce05c727a51c093b14816a88c0cdd33951396d93;p=org.ibex.core.git diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java index 1da4c54..327d35c 100644 --- a/src/org/xwt/js/JS.java +++ b/src/org/xwt/js/JS.java @@ -1,53 +1,174 @@ -// 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. JS itself is actually a class + * implementing the absolute minimal amount of functionality for an + * Object which can be manipulated by JavaScript code. + */ +public class JS { + + // Public Helper Methods ////////////////////////////////////////////////////////////////////// + + /** parse and compile a function */ + public static JSFunction parse(String sourceName, int firstLine, Reader sourceCode) throws IOException { + return new JSFunction(sourceName, firstLine, sourceCode, null); + } + + /** 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 new Long(0); + 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 new Double((String)o); } catch (NumberFormatException e) { return new Double(Double.NaN); } + 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() + " 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 //////////////////////////////////////////////////////////////////// -/** all objects other than Strings and Numbers which are exposed to JS code must implement this interface */ -public interface JS { - - public Object get(Object key) throws JS.Exn; - public Object put(Object key, Object val) throws JS.Exn; - public Object[] enumerateProperties(); - public String coerceToString() throws JS.Exn; - public Num coerceToNumber() throws JS.Exn; - public Object call(Object[] args) throws JS.Exn; - - /** 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. */ + // 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; + + // FEATURE: be smart here; perhaps intern + public static final Number N(int i) { return new Integer(i); } + public static final Number N(long l) { return new Long(l); } + public static final Number N(double d) { return new Double(d); } + public static final Boolean B(boolean b) { return b ? Boolean.TRUE : Boolean.FALSE; } + + private static Enumeration emptyEnumeration = new Enumeration() { + public boolean hasMoreElements() { return false; } + public Object nextElement() { throw new NoSuchElementException(); } + }; + + private Hash entries = null; + public Enumeration keys() { return entries == null ? emptyEnumeration : entries.keys(); } + public Object get(Object key) { return entries == null ? null : entries.get(key, null); } + public void put(Object key, Object val) { if (entries == null) entries = new Hash(); entries.put(key, null, val); } + + // note that we don't actually implement trappable... we just provide these for subclasses which choose to + public JSTrap getTrap(Object key) { return entries == null ? null : (JSTrap)entries.get(key, JSTrap.class); } + public void putTrap(Object key, JSTrap t) { if (entries == null) entries = new Hash(); entries.put(key, JSTrap.class, t); } + + public Number coerceToNumber() { throw new JS.Exn("tried to coerce a JavaScript object to a Number"); } + public String coerceToString() { throw new JS.Exn("tried to coerce a JavaScript object to a String"); } + public boolean coerceToBoolean() { throw new JS.Exn("tried to coerce a JavaScript object to a Boolean"); } + + public String typeName() { return "object"; } + + + // Inner Classes ///////////////////////////////////////////////////////////////////////// + + /** An exception which can be thrown and caught by JavaScript code */ public static class Exn extends RuntimeException { - private Object js = null; - public Exn(Object js) { this.js = js; } - public Object getObject() { return js; } - } - - /** Any object which becomes part of the scope chain must support this interface */ - public static interface Scope extends JS { - public boolean has(Object key); - public void declare(String s); - public JS getParentScope(); - } - - /** A mutable, boxed numeric value. These are recycled -- never duplicate references -- use duplicate() instead. */ - public static class Num implements Cloneable, JS { - - private Num() { } - - public boolean isDouble = false; - public long longVal = -1; - public double doubleVal = -1; - - private static Vec pool = new Vec(); - public static synchronized void recycle(Num n) { pool.push(n); } - public static synchronized Num getOne() { return (pool.size() > 0) ? (Num)pool.pop() : new Num(); } - - public Num duplicate() { try { return (Num)clone(); } catch (CloneNotSupportedException c) { throw new Error(c); } } - - public Object get(Object key) throws JS.Exn { return null; } - public Object put(Object key, Object val) throws JS.Exn { throw new JS.Exn("attempt to set a property on a Number"); } - public Object[] enumerateProperties() { return new Object[] { }; } - public String coerceToString() throws JS.Exn { return isDouble ? String.valueOf(doubleVal) : String.valueOf(longVal); } - public Num coerceToNumber() throws JS.Exn { return duplicate(); } - public Object call(Object[] args) throws JS.Exn { throw new JS.Exn("attempt to apply the () operator to a Number"); } - + private Object js = null; + public Exn(Object js) { this.js = js; } + public String toString() { return "JS.Exn: " + js; } + public String getMessage() { return toString(); } + public Object getObject() { return js; } } + + /** the result of a graft */ + // FIXME: uber-broken + public static class Graft extends JSCallable { + private JS graftee; + private Object replaced_key; + private Object replaced_val; + public Graft(Object graftee, Object key, Object val) { + if (graftee instanceof JSArray) throw new JS.Exn("can't graft onto JSArrays (yet)"); + if (graftee instanceof JSCallable) throw new JS.Exn("can't graft onto JSCallables (yet)"); + if (graftee instanceof JSScope) throw new JS.Exn("can't graft onto JSScopes (yet)"); + this.graftee = (JS)graftee; + replaced_key = key; + replaced_val = val; + } + public boolean equals(Object o) { return (this == o || graftee.equals(o)); } + public int hashCode() { return graftee.hashCode(); } + public Object get(Object key) { return replaced_key.equals(key) ? replaced_val : graftee.get(key); } + public void put(Object key, Object val) { graftee.put(key, val); } + /* + public Object call(Object method, JSArray args) { + if (replaced_key.equals(method)) return ((JSCallable)replaced_val).call(null, args); + else if (graftee instanceof JSCallable) return ((JSCallable)graftee).call(method, args); + else throw new JS.Exn("cannot call this value"); + } + */ + public Number coerceToNumber() { return graftee.coerceToNumber(); } + public String coerceToString() { return graftee.coerceToString(); } + public boolean coerceToBoolean() { return graftee.coerceToBoolean(); } + public String typeName() { return graftee.typeName(); } + public Enumeration keys() { + return new Enumeration() { + Enumeration graftee_enumeration = graftee.keys(); + boolean returned_replaced = false; + public boolean hasMoreElements() { + if (graftee_enumeration.hasMoreElements()) return true; + return !returned_replaced; + } + public Object nextElement() { + if (!graftee_enumeration.hasMoreElements()) { + if (returned_replaced) throw new NoSuchElementException(); + returned_replaced = true; + return replaced_key; + } else { + Object ret = graftee_enumeration.nextElement(); + if (!returned_replaced && ret.equals(replaced_key)) returned_replaced = true; + return ret; + } + } + }; + } + } } + + + +