X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Fjs%2FJS.java;h=cdc7e359d9630c89df119b173dcedda79d1db45c;hb=e8442c40f5b8c03a4e6993cbcc9ce64dddab6a90;hp=72c9e2a49e226d1689a74f91590c4e2b8bdba634;hpb=6eec0b10a11c69f71b3949acfb19d4c4fcbe1a8a;p=org.ibex.core.git diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java index 72c9e2a..cdc7e35 100644 --- a/src/org/xwt/js/JS.java +++ b/src/org/xwt/js/JS.java @@ -6,107 +6,195 @@ import java.io.*; import java.util.*; /** - * The public API for the JS engine; JS itself is actually a class - * implementing the minimal amount of functionality for an Object - * which can be manipulated by JavaScript code. + * 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. The static + * methods, fields, and inner classes of JS define the publicly + * visible API for the XWT JavaScript engine; code outside this + * package should never depend on anything not defined in this file. */ public abstract class JS { + // Public Helper Methods ////////////////////////////////////////////////////////////////////// + /** parse and compile a function */ + public static CompiledFunction parse(String sourceName, int firstLine, Reader sourceCode) throws IOException { + return new CompiledFunction(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 Number) return o.equals(new Integer(0)); - return true; + 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); - 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(); - throw new Error("toNumber() got object of type " + o.getClass().getName() + " which we don't know how to handle"); + if (o == null) return new Long(0); + if (o instanceof Number) return ((Number)o); + // FIXME: There are about 3 pages of rules in ecma262 about string to number conversions + // We aren't even close to following all those rules + 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"); } - - + // Instance Methods //////////////////////////////////////////////////////////////////// public abstract Object get(Object key) throws JS.Exn; public abstract void put(Object key, Object val) throws JS.Exn; public abstract Object[] keys(); + public abstract Object callMethod(Object method, JS.Array args, boolean justChecking); public Number coerceToNumber() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a Number"); } public String coerceToString() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a String"); } public boolean coerceToBoolean() { throw new Error("you cannot coerce a " + this.getClass().getName() + " into a Boolean"); } + + public String typeName() { return "object"; } - // Subclasses ///////////////////////////////////////////////////////////////////////// + // Inner Classes ///////////////////////////////////////////////////////////////////////// - /** A slightly more featureful version of JS */ + /** A sensible implementation of the abstract methods in the JS class */ public static class Obj extends JS { - private Hash entries = new Hash(); - private boolean sealed = false; - public Obj() { this(false); } - public Obj(boolean sealed) { this.sealed = sealed; } - public void setSeal(boolean sealed) { this.sealed = sealed; } - public Object get(Object key) { return entries.get(key); } - public void put(Object key, Object val) { if (!sealed) entries.put(key, val); } - public Object[] keys() { return(entries.keys()); } + private Hash entries = new Hash(); + private boolean sealed = false; + public Obj() { this(false); } + public Obj(boolean sealed) { this.sealed = sealed; } + /** a sealed object cannot have its properties modified */ + public void setSeal(boolean sealed) { this.sealed = sealed; } + public void put(Object key, Object val) { if (!sealed) entries.put(key, val); } + public Object[] keys() { return(entries.keys()); } + public Object get(Object key) { + if(callMethod((String)key,null,true) == Boolean.TRUE) + return new Internal.CallableStub(this,key); + return entries.get(key); + } + public Object callMethod(Object method, JS.Array args, boolean checkOnly) throws JS.Exn { + if(checkOnly) return Boolean.FALSE; + Object o = get(method); + if(o instanceof JS.Callable) { + return ((JS.Callable)o).call(args); + } else if(o == null) { + throw new JS.Exn("Attempted to call non-existent method: " + method); + } else { + throw new JS.Exn("Attempted to call a non-method: " +method); + } + } } - /** An exception which can be thrown and caught by JavaScripts */ + /** 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 String toString() { return "JS.Exn: " + js; } - public String getMessage() { return toString(); } - public Object getObject() { return js; } + 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 publicly-visible face of JavaScript Array objects */ + public static class Array extends ArrayImpl { + public Array() { } + public Array(int size) { super(size); } + public void setSize(int i) { super.setSize(i); } + public int length() { return super.length(); } + public Object elementAt(int i) { return super.elementAt(i); } + public void addElement(Object o) { super.addElement(o); } + public void setElementAt(Object o, int i) { super.setElementAt(o, i); } + public Object get(Object key) { return super._get(key); } + public void put(Object key, Object val) { super._put(key, val); } + } + /** 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, false); } - public Scope(Scope parentScope, boolean sealed) { - super(sealed); - if (parentScope == this) throw new Error("can't make a scope its own parent!"); - this.parentScope = parentScope; - } - public Scope getParentScope() { return parentScope; } - - // transparent scopes are not returned by THIS - public boolean isTransparent() { return false; } - - public boolean has(Object key) { return super.get(key) != null; } - public Object get(Object key) { - if (!has(key)) return parentScope == null ? null : getParentScope().get(key); - Object ret = super.get(key); return ret == NULL ? null : ret; - } - public void put(Object key, Object val) { - if (!has(key) && parentScope != null) getParentScope().put(key, val); - else super.put(key, val == null ? NULL : val); - } - public Object[] keys() { throw new Error("you can't enumerate the properties of a Scope"); } - public void declare(String s) { - if (isTransparent()) getParentScope().declare(s); - else super.put(s, NULL); - } + public static class Scope extends ScopeImpl { + public Scope(Scope parentScope) { this(parentScope, false); } + public Scope(Scope parentScope, boolean sealed) { super(parentScope, sealed); } + /** transparent scopes are not returned by THIS */ + public boolean isTransparent() { return super.isTransparent(); } + public boolean has(Object key) { return super.has(key); } + public Object get(Object key) { return super._get(key); } + public void put(Object key, Object val) { super._put(key, val); } + public void declare(String s) { super.declare(s); } } - public static CompiledFunction parse(String sourceName, int firstLine, Reader sourceCode, JS.Scope parentScope) throws IOException { - return new CompiledFunction(sourceName, firstLine, sourceCode, parentScope); - } - /** anything that is callable with the () operator */ public static abstract class Callable extends JS.Obj { - public abstract Object call(Array args) throws JS.Exn; + public abstract Object call(JS.Array args) throws JS.Exn; + } + + /** a Callable which was compiled from JavaScript code */ + public static class CompiledFunction extends CompiledFunctionImpl { + CompiledFunction(String sourceName, int firstLine, Reader sourceCode, Scope scope) throws IOException { + super(sourceName, firstLine, sourceCode, scope); + } + } + + /** a scope that is populated with js objects and functions normally found in the global scope */ + public static class GlobalScope extends GlobalScopeImpl { + public GlobalScope() { this(null); } + public GlobalScope(JS.Scope parent) { super(parent); } } + public static final JS Math = new org.xwt.js.Math(); + + /** encapsulates a single JavaScript thread; the JS.Thread->java.lang.Thread mapping is 1:1 */ + public static class Thread { + + CompiledFunction currentCompiledFunction = null; + Vec stack = new Vec(); + int pc; + + /** binds this thread to the current Java Thread */ + public void bindToCurrentJavaThread() { javaThreadToJSThread.put(java.lang.Thread.currentThread(), this); } + + /** returns the line of code that is currently executing */ + public int getLine() { return currentCompiledFunction == null ? -1 : currentCompiledFunction.getLine(pc); } + + /** returns the name of the source code file which declared the currently executing function */ + public String getSourceName() { return currentCompiledFunction == null ? null : currentCompiledFunction.getSourceName(); } + + /** fetches the currently-executing javascript function */ + public JS.CompiledFunction getCurrentCompiledFunction() { return currentCompiledFunction; } + + + // Statics /////////////////////////////////////////////////////////////////////// + + private static Hashtable javaThreadToJSThread = new Hashtable(); + + /** returns the JS thread for a given Java thread, creating one if necessary */ + public static JS.Thread fromJavaThread(java.lang.Thread t) { + JS.Thread ret = (JS.Thread)javaThreadToJSThread.get(t); + if (ret == null) { + ret = new JS.Thread(); + ret.bindToCurrentJavaThread(); + } + return ret; + } + + public static JS.Thread currentJSThread() { + return fromJavaThread(java.lang.Thread.currentThread()); + } + } }