From 8bcd55a21b0835d098a62a66878ea88c17c6463b Mon Sep 17 00:00:00 2001
From: megacz <megacz@xwt.org>
Date: Fri, 30 Jan 2004 06:59:30 +0000
Subject: [PATCH] 2003/04/30 04:39:09

darcs-hash:20040130065930-2ba56-671a48d62ef4f25936abc06c3cf50bb223dd1234.gz
---
 src/org/xwt/js/JS.java |   52 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 src/org/xwt/js/JS.java

diff --git a/src/org/xwt/js/JS.java b/src/org/xwt/js/JS.java
new file mode 100644
index 0000000..f086de6
--- /dev/null
+++ b/src/org/xwt/js/JS.java
@@ -0,0 +1,52 @@
+// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
+
+package org.xwt.js;
+import org.xwt.util.*;
+
+/** 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 static class Exn extends RuntimeException {
+	private Object js = null;
+	public Exn(Object js) { this.js = js; }
+	public Object getObject() { return js; }
+    }
+
+    /** 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 JS getParentScope();
+    }
+
+    /** 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"); }
+	
+    }
+}
-- 
1.7.10.4