Mercurial > lasercutter

     1 /**

     2  *   Copyright (c) Rich Hickey. All rights reserved.

     3  *   The use and distribution terms for this software are covered by the

     4  *   Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)

     5  *   which can be found in the file epl-v10.html at the root of this distribution.

     6  *   By using this software in any fashion, you are agreeing to be bound by

     7  * 	 the terms of this license.

     8  *   You must not remove this notice, or any other, from this software.

     9  **/

    10 

    11 /* rich Mar 25, 2006 11:42:47 AM */

    12 

    13 package clojure.lang;

    14 

    15 import java.io.Serializable;

    16 import java.io.ObjectStreamException;

    17 

    18 

    19 public class Symbol extends AFn implements IObj, Comparable, Named, Serializable{

    20 //these must be interned strings!

    21 final String ns;

    22 final String name;

    23 final int hash;

    24 final IPersistentMap _meta;

    25 

    26 public String toString(){

    27 	if(ns != null)

    28 		return ns + "/" + name;

    29 	return name;

    30 }

    31 

    32 public String getNamespace(){

    33 	return ns;

    34 }

    35 

    36 public String getName(){

    37 	return name;

    38 }

    39 

    40 static public Symbol intern(String ns, String name){

    41 	return new Symbol(ns == null ? null : ns.intern(), name.intern());

    42 }

    43 

    44 static public Symbol intern(String nsname){

    45 	int i = nsname.lastIndexOf('/');

    46 	if(i == -1 || nsname.equals("/"))

    47 		return new Symbol(null, nsname.intern());

    48 	else

    49 		return new Symbol(nsname.substring(0, i).intern(), nsname.substring(i + 1).intern());

    50 }

    51 

    52 static public Symbol create(String name_interned){

    53 	return new Symbol(null, name_interned);

    54 }

    55 

    56 static public Symbol create(String ns_interned, String name_interned){

    57 	return new Symbol(ns_interned, name_interned);

    58 }

    59 

    60 private Symbol(String ns_interned, String name_interned){

    61 	this.name = name_interned;

    62 	this.ns = ns_interned;

    63 	this.hash = Util.hashCombine(name.hashCode(), Util.hash(ns));

    64 	this._meta = null;

    65 }

    66 

    67 public boolean equals(Object o){

    68 	if(this == o)

    69 		return true;

    70 	if(!(o instanceof Symbol))

    71 		return false;

    72 

    73 	Symbol symbol = (Symbol) o;

    74 

    75 	//identity compares intended, names are interned

    76 	return name == symbol.name && ns == symbol.ns;

    77 }

    78 

    79 public int hashCode(){

    80 	return hash;

    81 }

    82 

    83 public IObj withMeta(IPersistentMap meta){

    84 	return new Symbol(meta, ns, name);

    85 }

    86 

    87 private Symbol(IPersistentMap meta, String ns, String name){

    88 	this.name = name;

    89 	this.ns = ns;

    90 	this._meta = meta;

    91 	this.hash = Util.hashCombine(name.hashCode(), Util.hash(ns));

    92 }

    93 

    94 public int compareTo(Object o){

    95 	Symbol s = (Symbol) o;

    96 	if(this.equals(o))

    97 		return 0;

    98 	if(this.ns == null && s.ns != null)

    99 		return -1;

   100 	if(this.ns != null)

   101 		{

   102 		if(s.ns == null)

   103 			return 1;

   104 		int nsc = this.ns.compareTo(s.ns);

   105 		if(nsc != 0)

   106 			return nsc;

   107 		}

   108 	return this.name.compareTo(s.name);

   109 }

   110 

   111 private Object readResolve() throws ObjectStreamException{

   112 	return intern(ns, name);

   113 }

   114 

   115 public Object invoke(Object obj) throws Exception{

   116 	return RT.get(obj, this);

   117 }

   118 

   119 public Object invoke(Object obj, Object notFound) throws Exception{

   120 	return RT.get(obj, this, notFound);

   121 }

   122 

   123 public IPersistentMap meta(){

   124 	return _meta;

   125 }

   126 }
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 21 Aug 2010 06:25:44 -0400
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