1 files changed, 173 insertions, 0 deletions
diff --git a/src/org/clojure/runtime/ListMap.java b/src/org/clojure/runtime/ListMap.java
new file mode 100644
index 00000000..18b17ee3
--- /dev/null
+++ b/src/org/clojure/runtime/ListMap.java
@@ -0,0 +1,173 @@
+/**
+ *   Copyright (c) Rich Hickey. All rights reserved.
+ *   The use and distribution terms for this software are covered by the
+ *   Common Public License 1.0 (http://opensource.org/licenses/cpl.php)
+ *   which can be found in the file CPL.TXT at the root of this distribution.
+ *   By using this software in any fashion, you are agreeing to be bound by
+ * 	 the terms of this license.
+ *   You must not remove this notice, or any other, from this software.
+ **/
+
+/* rich Jun 6, 2006 */
+
+package org.clojure.runtime;
+
+import java.util.Iterator;
+
+public class ListMap implements IMap
+{
+final Entry entries;
+final int _count;
+
+public ListMap(){
+	this.entries = null;
+	this._count = 0;
+}
+
+public ListMap(Object key, Object val){
+	this.entries = Entry.create(key, val, null);
+	this._count = 1;
+}
+
+ListMap(int count, Entry entries){
+	this._count = count;
+	this.entries = entries;
+}
+
+
+
+static class Entry implements IMapEntry{
+	final Object _key;
+	final Object _val;
+
+	Entry(Object key,Object val){
+		this._key = key;
+		this._val = val;
+		}
+
+    Entry rest(){
+        return null;
+    }
+
+    static Entry create(Object key,Object val,Entry rest){
+        if(rest == null)
+            return new Entry(key,val);
+        return new EntryLink(key, val, rest);
+    }
+
+	public Object key(){
+		return _key;
+	}
+
+	public Object val(){
+		return _val;
+	}
+}
+
+static class EntryLink extends Entry{
+	final Entry _rest;
+
+	EntryLink(Object key,Object val,Entry rest){
+        super(key,val);
+		this._rest = rest;
+		}
+
+    Entry rest(){
+        return _rest;
+    }
+}
+
+public int count(){
+	return _count;
+}
+
+public boolean contains(Object key){
+	return find(key) != null;
+}
+
+public Entry find(Object key){
+	for(Entry e = entries;e != null;e = e.rest())
+		{
+		if(equalKey(key,e._key))
+			return e;
+		}
+	return null;
+}
+
+public IMap add(Object key){
+	return put(key, null);
+}
+
+public IMap put(Object key, Object val){
+	Entry remEntries = doRemove(entries, key);
+	int incr = (remEntries == entries) ? 1 : 0;
+	return new ListMap(_count + incr, Entry.create(key, val, remEntries));
+}
+
+Entry doRemove(Entry e, Object key){
+	if(e == null)
+		return null;
+	else if(equalKey(key,e._key))
+		{
+		return e.rest();
+		}
+	else
+		{
+		Entry er = doRemove(e.rest(), key);
+		if(er != e.rest()) //removed in tail
+			return Entry.create(e._key, e._val, er);
+		return e;
+		}
+}
+
+public IMap remove(Object key){
+	Entry remEntries = doRemove(entries, key);
+	if(remEntries == entries) //didn't have key
+		return this;
+	return new ListMap(_count - 1, remEntries);
+}
+
+public Object get(Object key){
+	Entry e = find(key);
+	if(e != null)
+		return e._val;
+	return null;
+}
+
+public int capacity(){
+	return count();
+}
+
+static class Iter implements Iterator{
+	Entry e;
+
+	Iter(Entry e)
+	{
+	this.e = e;
+	}
+
+	public boolean hasNext(){
+		return e != null;
+	}
+
+	public Object next(){
+		Entry ret = e;
+		e = e.rest();
+		return ret;
+	}
+
+	public void remove(){
+		throw new UnsupportedOperationException();
+	}
+}
+
+public Iterator iterator(){
+	return new Iter(entries);
+}
+
+boolean equalKey(Object k1,Object k2){
+    if(k1 == null)
+        return k2 == null;
+    return k1.equals(k2);
+}
+}