|
Java example source code file (LazySeq.java)
The LazySeq.java Java example source code/** * 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 Jan 31, 2009 */ package clojure.lang; import java.util.*; public final class LazySeq extends Obj implements ISeq, Sequential, List, IPending, IHashEq{ private IFn fn; private Object sv; private ISeq s; public LazySeq(IFn fn){ this.fn = fn; } private LazySeq(IPersistentMap meta, ISeq s){ super(meta); this.fn = null; this.s = s; } public Obj withMeta(IPersistentMap meta){ return new LazySeq(meta, seq()); } final synchronized Object sval(){ if(fn != null) { sv = fn.invoke(); fn = null; } 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; return c; } public Object first(){ seq(); if(s == null) return null; return s.first(); } public ISeq next(){ seq(); if(s == null) return null; return s.next(); } public ISeq more(){ seq(); if(s == null) return PersistentList.EMPTY; return s.more(); } public ISeq cons(Object o){ return RT.cons(o, seq()); } public IPersistentCollection empty(){ return PersistentList.EMPTY; } public boolean equiv(Object o){ ISeq s = seq(); if(s != null) return s.equiv(o); else return (o instanceof Sequential || o instanceof List) && RT.seq(o) == null; } public int hashCode(){ ISeq s = seq(); if(s == null) return 1; return Util.hash(s); } public int hasheq(){ return Murmur3.hashOrdered(this); } public boolean equals(Object o){ ISeq s = seq(); if(s != null) return s.equals(o); else return (o instanceof Sequential || o instanceof List) && RT.seq(o) == null; } // java.util.Collection implementation public Object[] toArray(){ return RT.seqToArray(seq()); } public boolean add(Object o){ throw new UnsupportedOperationException(); } public boolean remove(Object o){ throw new UnsupportedOperationException(); } public boolean addAll(Collection c){ throw new UnsupportedOperationException(); } public void clear(){ throw new UnsupportedOperationException(); } public boolean retainAll(Collection c){ throw new UnsupportedOperationException(); } public boolean removeAll(Collection c){ throw new UnsupportedOperationException(); } public boolean containsAll(Collection c){ for(Object o : c) { if(!contains(o)) return false; } return true; } public Object[] toArray(Object[] a){ return RT.seqToPassedArray(seq(), a); } public int size(){ return count(); } public boolean isEmpty(){ return seq() == null; } public boolean contains(Object o){ for(ISeq s = seq(); s != null; s = s.next()) { if(Util.equiv(s.first(), o)) return true; } return false; } public Iterator iterator(){ return new SeqIterator(this); } //////////// List stuff ///////////////// private List reify(){ return new ArrayList(this); } public List subList(int fromIndex, int toIndex){ return reify().subList(fromIndex, toIndex); } public Object set(int index, Object element){ throw new UnsupportedOperationException(); } public Object remove(int index){ throw new UnsupportedOperationException(); } public int indexOf(Object o){ ISeq s = seq(); for(int i = 0; s != null; s = s.next(), i++) { if(Util.equiv(s.first(), o)) return i; } return -1; } public int lastIndexOf(Object o){ return reify().lastIndexOf(o); } public ListIterator listIterator(){ return reify().listIterator(); } public ListIterator listIterator(int index){ return reify().listIterator(index); } public Object get(int index){ return RT.nth(this, index); } public void add(int index, Object element){ throw new UnsupportedOperationException(); } public boolean addAll(int index, Collection c){ throw new UnsupportedOperationException(); } synchronized public boolean isRealized(){ return fn == null; } } Other Java examples (source code examples)Here is a short list of links related to this Java LazySeq.java source code file: |
... this post is sponsored by my books ... | |
#1 New Release! |
FP Best Seller |
Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.
A percentage of advertising revenue from
pages under the /java/jwarehouse
URI on this website is
paid back to open source projects.