-// 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 java.io.*;
import java.util.*;
-/** The public API for the JS engine */
-// FEATURE: try using mutable, recycled 'Num' objects
+/**
+ * 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.
+ */
public abstract class JS {
+
// Static Methods //////////////////////////////////////////////////////////////////////
- public static Function getCurrentFunction() {
- return (Function)currentFunction.get(Thread.currentThread());
- }
- public static String getCurrentFunctionSourceName() {
- return getCurrentFunctionSourceName(Thread.currentThread());
- }
+ private static Hashtable currentFunction = new Hashtable();
+ public static Function getCurrentFunction() { return (Function)currentFunction.get(Thread.currentThread()); }
+ public static String getCurrentFunctionSourceName() { return getCurrentFunctionSourceName(Thread.currentThread()); }
+ public static String getFileAndLine() { return getCurrentFunctionSourceName() + ":" + getCurrentFunction().getLine(); }
public static String getCurrentFunctionSourceName(Thread t) {
Function f = (Function)currentFunction.get(t);
if (f == null) return "null";
return f.getSourceName();
}
- public static String getFileAndLine() {
- return "unknown:??";
+
+ 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 static long toLong(Object o) { return toNumber(o).longValue(); }
+ public static double toDouble(Object o) { return toNumber(o).doubleValue(); }
+ 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");
}
// Subclasses /////////////////////////////////////////////////////////////////////////
+ /** A slightly more featureful version of JS */
public static class Obj extends JS {
private Hash entries = new Hash();
private boolean sealed = false;
public Object[] keys() { return(entries.keys()); }
}
+ /** An exception which can be thrown and caught by JavaScripts */
public static class Exn extends RuntimeException {
private Object js = null;
public Exn(Object js) { this.js = js; }
- public String toString() { return "JS.Exn: " + js.toString(); }
+ public String toString() { return "JS.Exn: " + js; }
public String getMessage() { return toString(); }
public Object getObject() { return js; }
}
+ /** A JavaScript Array */
public static class Array extends Obj {
private Vec vec = new Vec();
public Array() { }
}
}
public void put(Object key, Object val) {
- if (key.equals("length")) vec.setSize(Parser.toNumber(val).intValue());
+ if (key.equals("length")) vec.setSize(toNumber(val).intValue());
int i = intVal(key);
if (i == Integer.MIN_VALUE) super.put(key, val);
else {
public void setElementAt(Object o, int i) { vec.setElementAt(o, i); }
}
- public static Hashtable currentFunction = new Hashtable();
- public static abstract class Function extends Obj {
- public abstract Object _call(JS.Array args) throws JS.Exn;
- public String getSourceName() throws JS.Exn { return "unknown"; }
- public final Object call(JS.Array args) throws JS.Exn { return _call(args); }
- }
-
- public static class Script extends Function {
- Vector e = null;
- private Script(Vector e) { this.e = e; }
- public String getSourceName() throws JS.Exn { return ((Parser.Expr)e.elementAt(0)).sourceName; }
- public Object _call(JS.Array args) throws JS.Exn {
- Scope rootScope = (Scope)args.elementAt(0);
+ /** Anything that is callable */
+ public static class Function extends Obj {
+ ByteCodeBlock bytecodes;
+ int line;
+ String sourceName;
+ Scope parentScope;
+ public Function() { this(-1, "unknown", null, null); }
+ public Function(int line, String sourceName, ByteCodeBlock bytecodes, Scope parentScope) {
+ this.sourceName = sourceName;
+ this.line = line;
+ this.bytecodes = bytecodes;
+ this.parentScope = parentScope;
+ }
+ public String getSourceName() throws JS.Exn { return sourceName; }
+ public int getLine() throws JS.Exn { return line; }
+ public Object _call(JS.Array args) throws JS.Exn, ByteCodeBlock.ControlTransferException {
+ if (bytecodes == null) throw new Error("tried to call() a JS.Function with bytecodes == null");
+ Vec stack = new Vec();
+ stack.push(args);
+ return bytecodes.eval(new FunctionScope(sourceName, parentScope), stack);
+ }
+ public final Object call(JS.Array args) throws JS.Exn {
Function saved = (Function)currentFunction.get(Thread.currentThread());
currentFunction.put(Thread.currentThread(), this);
try {
- for(int i=0; i<e.size(); i++)
- ((Parser.Expr)e.elementAt(i)).eval(rootScope);
- } catch (Parser.ReturnException e) {
- // ignore
- } catch (Parser.ControlTransferException e) {
- throw new JS.Exn("block threw a ControlTransferException: " + e);
+ return _call(args);
+ } catch (ByteCodeBlock.ReturnException e) { // ignore
+ return e.retval;
+ } catch (ByteCodeBlock.ControlTransferException e) {
+ throw new RuntimeException(getSourceName() + ":" + getLine() +
+ " error, ControlTransferException tried to leave a function");
} finally {
if (saved == null) currentFunction.remove(Thread.currentThread());
else currentFunction.put(Thread.currentThread(), saved);
}
+ }
+ }
+
+ public static class Script extends Function {
+ Vector e = null;
+ private Script(Vector e) { this.e = e; }
+ public String getSourceName() throws JS.Exn { return ((ByteCodeBlock)e.elementAt(0)).getSourceName(); }
+ public Object _call(JS.Array args) throws JS.Exn, ByteCodeBlock.ControlTransferException {
+ Scope rootScope = (Scope)args.elementAt(0);
+ for(int i=0; i<e.size(); i++) ((ByteCodeBlock)e.elementAt(i)).eval(rootScope, new Vec());
return null;
}
public static Script parse(Reader r, String sourceName, int line) throws IOException {
try {
Vector exprs = new Vector();
while(true) {
- Parser.Expr ret = p.parseBlock(false);
+ ByteCodeBlock ret = p.parseStatement();
if (ret == null) break;
exprs.addElement(ret);
}
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 void declare(String s) {
+ if (isTransparent()) getParentScope().declare(s);
+ else super.put(s, NULL);
+ }
}
-
+ private class FunctionScope extends JS.Scope {
+ String sourceName;
+ public FunctionScope(String sourceName, Scope parentScope) { super(parentScope); this.sourceName = sourceName; }
+ public String getSourceName() { return sourceName; }
+ public Object get(Object key) throws JS.Exn {
+ if (key.equals("trapee")) return org.xwt.Trap.currentTrapee();
+ else if (key.equals("cascade")) return org.xwt.Trap.cascadeFunction;
+ return super.get(key);
+ }
+ }
}
projects / org.ibex.core.git / blobdiff