1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/clojure/lang/LazySeq.java	Sat Aug 21 06:25:44 2010 -0400
     1.3 @@ -0,0 +1,251 @@
     1.4 +/**
     1.5 + *   Copyright (c) Rich Hickey. All rights reserved.
     1.6 + *   The use and distribution terms for this software are covered by the
     1.7 + *   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
     1.8 + *   which can be found in the file epl-v10.html at the root of this distribution.
     1.9 + *   By using this software in any fashion, you are agreeing to be bound by
    1.10 + * 	 the terms of this license.
    1.11 + *   You must not remove this notice, or any other, from this software.
    1.12 + **/
    1.13 +
    1.14 +/* rich Jan 31, 2009 */
    1.15 +
    1.16 +package clojure.lang;
    1.17 +
    1.18 +import java.util.*;
    1.19 +
    1.20 +public final class LazySeq extends Obj implements ISeq, List{
    1.21 +
    1.22 +private IFn fn;
    1.23 +private Object sv;
    1.24 +private ISeq s;
    1.25 +
    1.26 +public LazySeq(IFn fn){
    1.27 +	this.fn = fn;
    1.28 +}
    1.29 +
    1.30 +private LazySeq(IPersistentMap meta, ISeq s){
    1.31 +	super(meta);
    1.32 +	this.fn = null;
    1.33 +	this.s = s;
    1.34 +}
    1.35 +
    1.36 +public Obj withMeta(IPersistentMap meta){
    1.37 +	return new LazySeq(meta, seq());
    1.38 +}
    1.39 +
    1.40 +final synchronized Object sval(){
    1.41 +	if(fn != null)
    1.42 +		{
    1.43 +		try
    1.44 +			{
    1.45 +			sv = fn.invoke();
    1.46 +			fn = null;
    1.47 +			}
    1.48 +		catch(Exception e)
    1.49 +			{
    1.50 +			throw new RuntimeException(e);
    1.51 +			}
    1.52 +		}
    1.53 +	if(sv != null)
    1.54 +		return sv;
    1.55 +	return s;
    1.56 +}
    1.57 +
    1.58 +final synchronized public ISeq seq(){
    1.59 +	sval();
    1.60 +	if(sv != null)
    1.61 +		{
    1.62 +		Object ls = sv;
    1.63 +		sv = null;
    1.64 +		while(ls instanceof LazySeq)
    1.65 +			{
    1.66 +			ls = ((LazySeq)ls).sval();
    1.67 +			}
    1.68 +		s = RT.seq(ls);
    1.69 +		}
    1.70 +	return s;
    1.71 +}
    1.72 +
    1.73 +public int count(){
    1.74 +	int c = 0;
    1.75 +	for(ISeq s = seq(); s != null; s = s.next())
    1.76 +		++c;                                                                                
    1.77 +	return c;
    1.78 +}
    1.79 +
    1.80 +public Object first(){
    1.81 +	seq();
    1.82 +	if(s == null)
    1.83 +		return null;
    1.84 +	return s.first();
    1.85 +}
    1.86 +
    1.87 +public ISeq next(){
    1.88 +	seq();
    1.89 +	if(s == null)
    1.90 +		return null;
    1.91 +	return s.next();	
    1.92 +}
    1.93 +
    1.94 +public ISeq more(){
    1.95 +	seq();
    1.96 +	if(s == null)
    1.97 +		return PersistentList.EMPTY;
    1.98 +	return s.more();
    1.99 +}
   1.100 +
   1.101 +public ISeq cons(Object o){
   1.102 +	return RT.cons(o, seq());
   1.103 +}
   1.104 +
   1.105 +public IPersistentCollection empty(){
   1.106 +	return PersistentList.EMPTY;
   1.107 +}
   1.108 +
   1.109 +public boolean equiv(Object o){
   1.110 +	return equals(o);
   1.111 +}
   1.112 +
   1.113 +public int hashCode(){
   1.114 +	return Util.hash(seq());
   1.115 +}
   1.116 +
   1.117 +public boolean equals(Object o){
   1.118 +	ISeq s = seq();
   1.119 +	if(s != null)
   1.120 +		return s.equiv(o);
   1.121 +	else
   1.122 +		return (o instanceof Sequential || o instanceof List) && RT.seq(o) == null;
   1.123 +}
   1.124 +
   1.125 +
   1.126 +// java.util.Collection implementation
   1.127 +
   1.128 +public Object[] toArray(){
   1.129 +	return RT.seqToArray(seq());
   1.130 +}
   1.131 +
   1.132 +public boolean add(Object o){
   1.133 +	throw new UnsupportedOperationException();
   1.134 +}
   1.135 +
   1.136 +public boolean remove(Object o){
   1.137 +	throw new UnsupportedOperationException();
   1.138 +}
   1.139 +
   1.140 +public boolean addAll(Collection c){
   1.141 +	throw new UnsupportedOperationException();
   1.142 +}
   1.143 +
   1.144 +public void clear(){
   1.145 +	throw new UnsupportedOperationException();
   1.146 +}
   1.147 +
   1.148 +public boolean retainAll(Collection c){
   1.149 +	throw new UnsupportedOperationException();
   1.150 +}
   1.151 +
   1.152 +public boolean removeAll(Collection c){
   1.153 +	throw new UnsupportedOperationException();
   1.154 +}
   1.155 +
   1.156 +public boolean containsAll(Collection c){
   1.157 +	for(Object o : c)
   1.158 +		{
   1.159 +		if(!contains(o))
   1.160 +			return false;
   1.161 +		}
   1.162 +	return true;
   1.163 +}
   1.164 +
   1.165 +public Object[] toArray(Object[] a){
   1.166 +	if(a.length >= count())
   1.167 +		{
   1.168 +		ISeq s = seq();
   1.169 +		for(int i = 0; s != null; ++i, s = s.next())
   1.170 +			{
   1.171 +			a[i] = s.first();
   1.172 +			}
   1.173 +		if(a.length > count())
   1.174 +			a[count()] = null;
   1.175 +		return a;
   1.176 +		}
   1.177 +	else
   1.178 +		return toArray();
   1.179 +}
   1.180 +
   1.181 +public int size(){
   1.182 +	return count();
   1.183 +}
   1.184 +
   1.185 +public boolean isEmpty(){
   1.186 +	return seq() == null;
   1.187 +}
   1.188 +
   1.189 +public boolean contains(Object o){
   1.190 +	for(ISeq s = seq(); s != null; s = s.next())
   1.191 +		{
   1.192 +		if(Util.equiv(s.first(), o))
   1.193 +			return true;
   1.194 +		}
   1.195 +	return false;
   1.196 +}
   1.197 +
   1.198 +public Iterator iterator(){
   1.199 +	return new SeqIterator(seq());
   1.200 +}
   1.201 +
   1.202 +//////////// List stuff /////////////////
   1.203 +private List reify(){
   1.204 +	return new ArrayList(this);
   1.205 +}
   1.206 +
   1.207 +public List subList(int fromIndex, int toIndex){
   1.208 +	return reify().subList(fromIndex, toIndex);
   1.209 +}
   1.210 +
   1.211 +public Object set(int index, Object element){
   1.212 +	throw new UnsupportedOperationException();
   1.213 +}
   1.214 +
   1.215 +public Object remove(int index){
   1.216 +	throw new UnsupportedOperationException();
   1.217 +}
   1.218 +
   1.219 +public int indexOf(Object o){
   1.220 +	ISeq s = seq();
   1.221 +	for(int i = 0; s != null; s = s.next(), i++)
   1.222 +		{
   1.223 +		if(Util.equiv(s.first(), o))
   1.224 +			return i;
   1.225 +		}
   1.226 +	return -1;
   1.227 +}
   1.228 +
   1.229 +public int lastIndexOf(Object o){
   1.230 +	return reify().lastIndexOf(o);
   1.231 +}
   1.232 +
   1.233 +public ListIterator listIterator(){
   1.234 +	return reify().listIterator();
   1.235 +}
   1.236 +
   1.237 +public ListIterator listIterator(int index){
   1.238 +	return reify().listIterator(index);
   1.239 +}
   1.240 +
   1.241 +public Object get(int index){
   1.242 +	return RT.nth(this, index);
   1.243 +}
   1.244 +
   1.245 +public void add(int index, Object element){
   1.246 +	throw new UnsupportedOperationException();
   1.247 +}
   1.248 +
   1.249 +public boolean addAll(int index, Collection c){
   1.250 +	throw new UnsupportedOperationException();
   1.251 +}
   1.252 +
   1.253 +
   1.254 +}