// 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 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 ////////////////////////////////////////////////////////////////////
-/** 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. */
+ 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 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"); }
+
+
+ // Subclasses /////////////////////////////////////////////////////////////////////////
+
+ 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()); }
+ }
+
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) {
+ if (o instanceof Number) {
+ int intVal = ((Number)o).intValue();
+ if (intVal == ((Number)o).doubleValue()) return intVal;
+ return Integer.MIN_VALUE;
+ }
+ if (!(o instanceof String)) return Integer.MIN_VALUE;
+ String s = (String)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) 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);
+ 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(Parser.toNumber(val).intValue());
+ int i = intVal(key);
+ if (i == Integer.MIN_VALUE) super.put(key, val);
+ else {
+ if (i >= vec.size()) vec.setSize(i+1);
+ vec.setElementAt(val, i);
+ }
+ }
+ 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 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);
+ 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 interface Scope extends JS {
- public boolean has(Object key);
- public void declare(String s);
- public JS getParentScope();
+ 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); 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);}
}
- /** 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"); }
-
- }
+
}
+
+
+
+
projects / org.ibex.core.git / blobdiff