added EnumerationSeq and support for Enumerations in seq

2 files changed, 74 insertions, 4 deletions

diff --git a/src/jvm/clojure/lang/EnumerationSeq.java b/src/jvm/clojure/lang/EnumerationSeq.java
new file mode 100644
index 00000000..daf62bc0
--- /dev/null
+++ b/src/jvm/clojure/lang/EnumerationSeq.java
@@ -0,0 +1,71 @@
+/**
+ *   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 Mar 3, 2008 */
+
+package clojure.lang;
+
+import java.util.Enumeration;
+
+public class EnumerationSeq extends ASeq{
+final Enumeration iter;
+final State state;
+
+static class State{
+	volatile Object val;
+	volatile Object _rest;
+}
+
+public static EnumerationSeq create(Enumeration iter){
+	if(iter.hasMoreElements())
+		return new EnumerationSeq(iter);
+	return null;
+}
+
+EnumerationSeq(Enumeration iter){
+	this.iter = iter;
+	state = new State();
+	this.state.val = state;
+	this.state._rest = state;
+}
+
+EnumerationSeq(IPersistentMap meta, Enumeration iter, State state){
+	super(meta);
+	this.iter = iter;
+	this.state = state;
+}
+
+public Object first(){
+	if(state.val == state)
+		synchronized(state)
+			{
+			if(state.val == state)
+				state.val = iter.nextElement();
+			}
+	return state.val;
+}
+
+public ISeq rest(){
+	if(state._rest == state)
+		synchronized(state)
+			{
+			if(state._rest == state)
+				{
+				first();
+				state._rest = create(iter);
+				}
+			}
+	return (ISeq) state._rest;
+}
+
+public EnumerationSeq withMeta(IPersistentMap meta){
+	return new EnumerationSeq(meta, iter, state);
+}
+}
diff --git a/src/jvm/clojure/lang/RT.java b/src/jvm/clojure/lang/RT.java
index 52bf88db..c61d8b8a 100644
--- a/src/jvm/clojure/lang/RT.java
+++ b/src/jvm/clojure/lang/RT.java
@@ -13,10 +13,7 @@
 package clojure.lang;
 
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.Arrays;
+import java.util.*;
 import java.util.regex.Matcher;
 import java.io.*;
 import java.lang.reflect.Array;
@@ -331,6 +328,8 @@ static public ISeq seq(Object coll){
 		return StringSeq.create((String) coll);
 	else if(coll instanceof Map)
 		return seq(((Map) coll).entrySet());
+	else if(coll instanceof Enumeration)
+		return EnumerationSeq.create(((Enumeration) coll));
 	else
 		throw new IllegalAccessError("Don't know how to create ISeq from arg");
 }