package org.xwt.js;
import org.xwt.util.*;
+import org.xwt.*;
import java.io.*;
import java.util.*;
*/
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);
+ public static Function parse(String sourceName, int firstLine, Reader sourceCode) throws IOException {
+ return new Function(sourceName, firstLine, sourceCode, null);
}
/** coerce an object to a Boolean */
public static Number toNumber(Object o) {
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); }
+
+ // 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 ////////////////////////////////////////////////////////////////////
public abstract Object get(Object key) throws JS.Exn;
- public abstract void put(Object key, Object val) throws JS.Exn;
+ public abstract Object put(Object key, Object val) throws JS.Exn;
public abstract Object[] keys();
-
- 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 Object callMethod(Object method, 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-function: " +method);
+ }
+
+ 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 /////////////////////////////////////////////////////////////////////////
/** A sensible implementation of the abstract methods in the JS class */
public static class Obj extends JS {
- private Hash entries = new Hash();
+ private Hash entries = null;
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 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()); }
+ public void setSeal(boolean sealed) { this.sealed = sealed; } ///< a sealed object cannot have its properties modified
+ public Object put(Object key, Object val) { put2(key, null, val); return null; }
+ protected void put2(Object key, Object key2, Object val) {
+ if (sealed) return;
+ if (entries == null) entries = new Hash();
+ entries.put(key, key2, val); }
+ public Object[] keys() { return entries == null ? new Object[0] : entries.keys(); }
+ public Object get(Object key) { return get(key, null); }
+ protected Object get(Object key, Object key2) {
+ if (entries == null) return null;
+ if(key2 == null && callMethod((String)key, null, true) == Boolean.TRUE)
+ return new Internal.CallableStub(this, key);
+ return entries.get(key, key2);
+ }
}
/** An exception which can be thrown and caught by JavaScript code */
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); }
+ public Object put(Object key, Object val) { super._put(key, val); return null; }
}
/** Any object which becomes part of the scope chain must support this interface */
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 isTransparent() { return super.isTransparent(); } //< transparent scopes are not returned by THIS
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 Object put(Object key, Object val) { super._put(key, val); return null; }
public void declare(String s) { super.declare(s); }
}
- /** anything that is callable with the () operator */
+ /** the result of a graft */
+ public static class Graft extends JS {
+ private JS graftee;
+ private Object replaced_key;
+ private Object replaced_val;
+ public Graft(JS graftee, Object key, Object val) {
+ if (graftee instanceof Array) throw new JS.Exn("can't graft onto Arrays (yet)");
+ if (graftee instanceof Callable) throw new JS.Exn("can't graft onto Callables (yet)");
+ if (graftee instanceof Scope) throw new JS.Exn("can't graft onto Scopes (yet)");
+ this.graftee = 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 Object put(Object key, Object val) { graftee.put(key, val); return null; }
+ public Object callMethod(Object method, Array args, boolean checkOnly) throws JS.Exn {
+ if (!replaced_key.equals(method)) return graftee.callMethod(method, args, checkOnly);
+ if (replaced_val instanceof Callable) return checkOnly ? Boolean.TRUE : ((Callable)replaced_val).call(args);
+ if (checkOnly) return Boolean.FALSE;
+ throw new JS.Exn("attempt to call non-function");
+ }
+ 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 Object[] keys() {
+ Object[] ret = graftee.keys();
+ for(int i=0; i<ret.length; i++) if (replaced_key.equals(ret[i])) return ret;
+ Object[] ret2 = new Object[ret.length + 1];
+ System.arraycopy(ret, 0, ret2, 0, ret.length);
+ ret2[ret2.length - 1] = replaced_key;
+ return ret2;
+ }
+ }
+
+ /** anything that is callable with the () operator and wasn't compiled from JS code */
public static abstract class Callable extends JS.Obj {
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();
+ public static class TailCall {
+ Function func = null;
+ JS.Array args = null;
+ public TailCall() { }
+ public TailCall set(Function func) { this.func = func; this.args = new JS.Array(); return this; }
+ public TailCall set(Function func, JS.Array args) { this.func = func; this.args = args; return this; }
+ }
- /** encapsulates a single JavaScript thread; the JS.Thread->java.lang.Thread mapping is 1:1 */
- public static class Thread {
+ /** encapsulates the state of a JavaScript "thread" (ie stack) */
+ public static class Context {
- 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); }
+ // Statics //////////////////////////////////////////////////////////////////////
- /** returns the line of code that is currently executing */
- public int getLine() { return currentCompiledFunction == null ? -1 : currentCompiledFunction.getLine(pc); }
+ /**
+ * Return this from call/get/put in order to make the interpreter pause. The interpreter will expect a value
+ * (the return from the call or the get) to be pushed onto the stack when it is resumed.
+ */
+ public static Object pause = new Object();
- /** returns the name of the source code file which declared the currently executing function */
- public String getSourceName() { return currentCompiledFunction == null ? null : currentCompiledFunction.getSourceName(); }
+ private int getLine_() { return current().f == null ? -1 : (pc < 0 || pc >= f.size) ? -1 : f.line[pc]; }
+ public static int getLine() { return current().getLine_(); }
+ public static String getSourceName() { return current().f == null ? null : current().f.sourceName; }
/** fetches the currently-executing javascript function */
- public JS.CompiledFunction getCurrentCompiledFunction() { return currentCompiledFunction; }
+ public static JS.Context current() { return (JS.Context)threadToContext.get(Thread.currentThread()); }
+ private static Hashtable threadToContext = new Hashtable();
- // Statics ///////////////////////////////////////////////////////////////////////
+ // Instance members and methods //////////////////////////////////////////////////////////////////////
- private static Hashtable javaThreadToJSThread = new Hashtable();
+ /** the currently-executing Function */
+ Function f = null;
- /** 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;
+ /** the currently-executing scope */
+ public Scope scope = null; // FIXME: do we really need this? the function should contain this info
+
+ /** the object stack */
+ Vec stack = new Vec();
+
+ /** the program counter */
+ int pc = 0;
+
+ public Context(Function function, Scope scope) {
+ if (scope == null) scope = new Scope(function.parentScope);
+ stack.push(new Function.CallMarker(this));
+ stack.push(new JS.Array());
+ this.f = function;
+ this.scope = scope;
}
-
- public static JS.Thread currentJSThread() {
- return fromJavaThread(java.lang.Thread.currentThread());
+
+ public Object resume() { return resume(null); }
+ public Object resume(Object o) {
+ Thread t = Thread.currentThread();
+ Context old = (Context)threadToContext.get(t);
+ try {
+ threadToContext.put(t, this);
+ stack.push(o);
+ return Function.eval(this);
+ } finally {
+ if (old == null) threadToContext.remove(t);
+ else threadToContext.put(t, old);
+ }
}
+
}
}
projects / org.ibex.core.git / blobdiff