first cut of chunked seqs

Chunked seqs, initial Java-side support

Author: richhickey

clojure.iml

@@ -11,6 +11,11 @@
     <setting name="buildJar" value="true" />
     <setting name="mainClass" value="clojure.lang.Compiler" />
   </component>
+  <component name="FacetManager">
+    <facet type="Clojure" name="Clojure">
+      <configuration />
+    </facet>
+  </component>
   <component name="NewModuleRootManager" inherit-compiler-output="false">
     <output url="file://$MODULE_DIR$/classes" />
     <exclude-output />

src/jvm/clojure/lang/ArrayChunk.java

@@ -0,0 +1,32 @@
+/**
+ *   Copyright (c) Rich Hickey. All rights reserved.
+ *   The use and distribution terms for this software are covered by the
+ *   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
+ *   which can be found in the file epl-v10.html 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 May 24, 2009 */
+
+package clojure.lang;
+
+public class ArrayChunk implements Indexed{
+
+final Object[] array;
+final int off;
+
+public ArrayChunk(Object[] array, int off){
+	this.array = array;
+	this.off = off;
+}
+
+public Object nth(int i){
+	return array[off + i];
+}
+
+public int count(){
+	return array.length - off;
+}
+}

src/jvm/clojure/lang/ChunkedCons.java

@@ -0,0 +1,74 @@
+/**
+ *   Copyright (c) Rich Hickey. All rights reserved.
+ *   The use and distribution terms for this software are covered by the
+ *   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
+ *   which can be found in the file epl-v10.html 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 May 25, 2009 */
+
+package clojure.lang;
+
+final public class ChunkedCons extends ASeq implements IChunkedSeq{
+
+final Indexed chunk;
+final ISeq _more;
+final int offset;
+
+ChunkedCons(IPersistentMap meta, Indexed chunk, int offset, ISeq more){
+	super(meta);
+	this.chunk = chunk;
+	this.offset = offset;
+	this._more = more;
+}
+public ChunkedCons(Indexed chunk, ISeq more){
+	this(chunk, 0, more);
+}
+
+public ChunkedCons(Indexed chunk, int offset, ISeq more){
+	this.chunk = chunk;
+	this.offset = offset;
+	this._more = more;
+}
+
+public Obj withMeta(IPersistentMap meta){
+	if(meta != _meta)
+		return new ChunkedCons(meta, chunk, offset, _more);
+	return this;
+}
+
+public Object first(){
+	return chunk.nth(offset);
+}
+
+public ISeq next(){
+	if(offset + 1 < chunk.count())
+		return new ChunkedCons(chunk, offset + 1, _more);
+	return chunkedNext();
+}
+
+public ISeq more(){
+	if(offset + 1 < chunk.count())
+		return new ChunkedCons(chunk, offset + 1, _more);
+	if(_more == null)
+		return PersistentList.EMPTY;
+	return _more;
+}
+
+public Indexed chunkedFirst(){
+	return chunk;
+}
+
+public ISeq chunkedNext(){
+	return chunkedMore().seq();	
+}
+
+public ISeq chunkedMore(){
+	if(_more == null)
+		return PersistentList.EMPTY;
+	return _more;
+}
+}

src/jvm/clojure/lang/IChunkedSeq.java

@@ -0,0 +1,23 @@
+/**
+ *   Copyright (c) Rich Hickey. All rights reserved.
+ *   The use and distribution terms for this software are covered by the
+ *   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
+ *   which can be found in the file epl-v10.html 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 May 24, 2009 */
+
+package clojure.lang;
+
+public interface IChunkedSeq extends ISeq{
+
+Indexed chunkedFirst() throws Exception;
+
+ISeq chunkedNext() throws Exception;
+
+ISeq chunkedMore() throws Exception;
+
+}

src/jvm/clojure/lang/IPersistentVector.java

@@ -10,11 +10,9 @@
  * You must not remove this notice, or any other, from this software.
  */
 
-public interface IPersistentVector extends Associative, Sequential, IPersistentStack, Reversible, Counted{
+public interface IPersistentVector extends Associative, Sequential, IPersistentStack, Reversible, Indexed{
 int length();
 
-Object nth(int i);
-
 IPersistentVector assocN(int i, Object val);
 
 IPersistentVector cons(Object o);

src/jvm/clojure/lang/Indexed.java

@@ -0,0 +1,17 @@
+/**
+ *   Copyright (c) Rich Hickey. All rights reserved.
+ *   The use and distribution terms for this software are covered by the
+ *   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
+ *   which can be found in the file epl-v10.html 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 May 24, 2009 */
+
+package clojure.lang;
+
+public interface Indexed extends Counted{
+Object nth(int i);
+}

src/jvm/clojure/lang/LazySeq.java

@@ -17,6 +17,7 @@
 public final class LazySeq extends Obj implements ISeq, List{
 
 private IFn fn;
+private Object sv;
 private ISeq s;
 
 public LazySeq(IFn fn){
@@ -33,26 +34,43 @@ public Obj withMeta(IPersistentMap meta){
 	return new LazySeq(meta, seq());
 }
 
-final synchronized public ISeq seq(){
+final synchronized Object sval(){
 	if(fn != null)
 		{
 		try
 			{
-			s = RT.seq(fn.invoke());
+			sv = fn.invoke();
 			fn = null;
 			}
 		catch(Exception e)
 			{
 			throw new RuntimeException(e);
 			}
 		}
+	if(sv != null)
+		return sv;
+	return s;
+}
+
+final synchronized public ISeq seq(){
+	sval();
+	if(sv != null)
+		{
+		Object ls = sv;
+		sv = null;
+		while(ls instanceof LazySeq)
+			{
+			ls = ((LazySeq)ls).sval();
+			}
+		s = RT.seq(ls);
+		}
 	return s;
 }
 
 public int count(){
 	int c = 0;
 	for(ISeq s = seq(); s != null; s = s.next())
-		++c;
+		++c;                                                                                
 	return c;
 }
 

src/jvm/clojure/lang/PersistentVector.java

@@ -89,19 +89,24 @@ final int tailoff(){
 	return cnt - tail.length;
 }
 
-public Object nth(int i){
+public Object[] nodeFor(int i){
 	if(i >= 0 && i < cnt)
 		{
 		if(i >= tailoff())
-			return tail[i & 0x01f];
+			return tail;
 		Object[] arr = root;
 		for(int level = shift; level > 0; level -= 5)
 			arr = (Object[]) arr[(i >>> level) & 0x01f];
-		return arr[i & 0x01f];
+		return arr;
 		}
 	throw new IndexOutOfBoundsException();
 }
 
+public Object nth(int i){
+	Object[] node = nodeFor(i);
+	return node[i & 0x01f];
+}
+
 public PersistentVector assocN(int i, Object val){
 	if(i >= 0 && i < cnt)
 		{
@@ -163,6 +168,75 @@ public PersistentVector cons(Object val){
 	return new PersistentVector(meta(), cnt + 1, newshift, newroot, new Object[]{val});
 }
 
+public IChunkedSeq chunkedSeq(){
+	if(count() == 0)
+		return null;
+	return new ChunkedSeq(this,0,0);
+}
+
+static public final class ChunkedSeq extends ASeq implements IChunkedSeq{
+
+	final PersistentVector vec;
+	final Object[] node;
+	final int i;
+	final int offset;
+
+	public ChunkedSeq(PersistentVector vec, int i, int offset){
+		this.vec = vec;
+		this.i = i;
+		this.offset = offset;
+		this.node = vec.nodeFor(i);
+	}
+
+	ChunkedSeq(IPersistentMap meta, PersistentVector vec, Object[] node, int i, int offset){
+		super(meta);
+		this.vec = vec;
+		this.node = node;
+		this.i = i;
+		this.offset = offset;
+	}
+
+	ChunkedSeq(PersistentVector vec, Object[] node, int i, int offset){
+		this.vec = vec;
+		this.node = node;
+		this.i = i;
+		this.offset = offset;
+	}
+
+	public Indexed chunkedFirst() throws Exception{
+		return new ArrayChunk(node, offset);
+		}
+
+	public ISeq chunkedNext(){
+		if(i + node.length < vec.cnt)
+			return new ChunkedSeq(vec,i+ node.length,0);
+		return null;
+		}
+
+	public ISeq chunkedMore(){
+		ISeq s = chunkedNext();
+		if(s == null)
+			return PersistentList.EMPTY;
+		return s;
+	}
+
+	public Obj withMeta(IPersistentMap meta){
+		if(meta == this._meta)
+			return this;
+		return new ChunkedSeq(meta, vec, node, i, offset);
+	}
+
+	public Object first(){
+		return node[offset];
+	}
+
+	public ISeq next(){
+		if(offset + 1 < node.length)
+			return new ChunkedSeq(vec, node, i, offset + 1);
+		return chunkedNext();
+	}
+}
+
 public IPersistentCollection empty(){
 	return EMPTY.withMeta(meta());
 }

src/jvm/clojure/lang/RT.java

@@ -494,10 +494,10 @@ static public IPersistentMap meta(Object x){
 }
 
 public static int count(Object o){
+	if(o instanceof Counted)
+		return ((Counted) o).count();
 	if(o == null)
 		return 0;
-	else if(o instanceof Counted)
-		return ((Counted) o).count();
 	else if(o instanceof IPersistentCollection) {
 		ISeq s = seq(o);
 		o = null;
@@ -712,10 +712,10 @@ static public Object dissoc(Object coll, Object key) throws Exception{
 }
 
 static public Object nth(Object coll, int n){
+	if(coll instanceof Indexed)
+		return ((Indexed) coll).nth(n);
 	if(coll == null)
 		return null;
-	else if(coll instanceof IPersistentVector)
-		return ((IPersistentVector) coll).nth(n);
 	else if(coll instanceof String)
 		return Character.valueOf(((String) coll).charAt(n));
 	else if(coll.getClass().isArray())