// Copyright 2002 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
-public interface JS {
+public abstract class JS {
+
+ // Static Methods //////////////////////////////////////////////////////////////////////
+
+ public static Function getCurrentFunction() {
+ return (Function)currentFunction.get(Thread.currentThread());
+ }
+ public static String getCurrentFunctionSourceName() {
+ return getCurrentFunctionSourceName(Thread.currentThread());
+ }
+ 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:??";
+ }
+
+
+ // 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[] enumerateProperties();
+ 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 abstract Number coerceToNumber() throws JS.Exn;
- public abstract boolean coerceToBoolean() throws JS.Exn;
- public abstract String coerceToString() throws JS.Exn;
+ // Subclasses /////////////////////////////////////////////////////////////////////////
- public static class Obj implements JS {
- private Hash entries;
- public Obj() { }
+ 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) { 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 void put(Object key, Object val) { if (!sealed) entries.put(key, val); }
+ public Object[] keys() { return(entries.keys()); }
}
+ 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 getMessage() { return toString(); }
+ public Object getObject() { return js; }
+ }
+
public static class Array extends Obj {
private Vec vec = new Vec();
private static int intVal(Object o) {
for(int i=0; i<s.length(); i++) if (s.charAt(i) < '0' || s.charAt(i) > '9') return Integer.MIN_VALUE;
return Integer.parseInt(s);
}
- public Object get(Object key) {
+ public Object get(Object key) throws JS.Exn {
+ // FIXME: HACK!
+ if (key.equals("cascade")) return org.xwt.Trap.cascadeFunction;
+ if (key.equals("trapee")) return org.xwt.Trap.currentTrapee();
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);
+ try {
+ return vec.elementAt(i);
+ } catch (ArrayIndexOutOfBoundsException e) {
+ throw new JS.Exn(e.getMessage());
+ }
}
public void put(Object key, Object val) {
- if (key.equals("length")) vec.setSize(Expr.toNumber(val).intValue());
+ if (key.equals("length")) vec.setSize(Parser.toNumber(val).intValue());
int i = intVal(key);
if (i == Integer.MIN_VALUE) super.put(key, val);
- else vec.setElementAt(val, i);
+ else {
+ if (i >= vec.size()) vec.setSize(i+1);
+ vec.setElementAt(val, i);
+ }
}
- public Object[] enumerateProperties() { return null; } // FIXME
- void addElement(Object o) { vec.addElement(o); }
+ public Object[] keys() {
+ Object[] sup = super.keys();
+ Object[] ret = new Object[vec.size() + 1 + sup.length];
+ System.arraycopy(sup, 0, ret, vec.size(), sup.length);
+ for(int i=0; i<vec.size(); i++) ret[i] = new Integer(i);
+ ret[vec.size()] = "length";
+ return ret;
+ }
+ public int length() { return vec.size(); }
+ public Object elementAt(int i) { return vec.elementAt(i); }
+ public void addElement(Object o) { vec.addElement(o); }
+ public void setElementAt(Object o, int i) { vec.setElementAt(o, i); }
}
- 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 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 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; }
- }
+ 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);
+ 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);
+ } finally {
+ if (saved == null) currentFunction.remove(Thread.currentThread());
+ else currentFunction.put(Thread.currentThread(), saved);
+ }
+ return null;
+ }
+ public static Script parse(Reader r, String sourceName, int line) throws IOException {
+ Parser p = new Parser(r, sourceName, line);
+ try {
+ Vector exprs = new Vector();
+ while(true) {
+ Parser.Expr ret = p.parseBlock(false);
+ if (ret == null || (ret.code == Parser.LC && ret.left == null)) break;
+ exprs.addElement(ret);
+ }
+ return new Script(exprs);
+ } catch (Exception e) {
+ if (Log.on) Log.log(Parser.class, e);
+ return null;
+ }
+ }
+ }
/** 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 Scope(Scope parentScope) { this(parentScope, false); }
+ public Scope(Scope parentScope, boolean sealed) { super(sealed); 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 getParentScope().get(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)) getParentScope().put(key, val);
+ if (!has(key) && parentScope != null) 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 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);}
}
+
}
projects / org.ibex.core.git / blobdiff