1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/clojure/lang/Namespace.java	Sat Aug 21 06:25:44 2010 -0400
     1.3 @@ -0,0 +1,243 @@
     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 23, 2008 */
    1.15 +
    1.16 +package clojure.lang;
    1.17 +
    1.18 +import java.io.ObjectStreamException;
    1.19 +import java.io.Serializable;
    1.20 +import java.util.concurrent.ConcurrentHashMap;
    1.21 +import java.util.concurrent.atomic.AtomicReference;
    1.22 +
    1.23 +public class Namespace extends AReference implements Serializable {
    1.24 +final public Symbol name;
    1.25 +transient final AtomicReference<IPersistentMap> mappings = new AtomicReference<IPersistentMap>();
    1.26 +transient final AtomicReference<IPersistentMap> aliases = new AtomicReference<IPersistentMap>();
    1.27 +
    1.28 +final static ConcurrentHashMap<Symbol, Namespace> namespaces = new ConcurrentHashMap<Symbol, Namespace>();
    1.29 +
    1.30 +public String toString(){
    1.31 +	return name.toString();
    1.32 +}
    1.33 +
    1.34 +Namespace(Symbol name){
    1.35 +	super(name.meta());
    1.36 +	this.name = name;
    1.37 +	mappings.set(RT.DEFAULT_IMPORTS);
    1.38 +	aliases.set(RT.map());
    1.39 +}
    1.40 +
    1.41 +public static ISeq all(){
    1.42 +	return RT.seq(namespaces.values());
    1.43 +}
    1.44 +
    1.45 +public Symbol getName(){
    1.46 +	return name;
    1.47 +}
    1.48 +
    1.49 +public IPersistentMap getMappings(){
    1.50 +	return mappings.get();
    1.51 +}
    1.52 +
    1.53 +public Var intern(Symbol sym){
    1.54 +	if(sym.ns != null)
    1.55 +		{
    1.56 +		throw new IllegalArgumentException("Can't intern namespace-qualified symbol");
    1.57 +		}
    1.58 +	IPersistentMap map = getMappings();
    1.59 +	Object o;
    1.60 +	Var v = null;
    1.61 +	while((o = map.valAt(sym)) == null)
    1.62 +		{
    1.63 +		if(v == null)
    1.64 +			v = new Var(this, sym);
    1.65 +		IPersistentMap newMap = map.assoc(sym, v);
    1.66 +		mappings.compareAndSet(map, newMap);
    1.67 +		map = getMappings();
    1.68 +		}
    1.69 +	if(o instanceof Var && ((Var) o).ns == this)
    1.70 +		return (Var) o;
    1.71 +
    1.72 +	if(v == null)
    1.73 +		v = new Var(this, sym);
    1.74 +
    1.75 +	warnOrFailOnReplace(sym, o, v);
    1.76 +
    1.77 +
    1.78 +	while(!mappings.compareAndSet(map, map.assoc(sym, v)))
    1.79 +		map = getMappings();
    1.80 +
    1.81 +	return v;
    1.82 +}
    1.83 +
    1.84 +private void warnOrFailOnReplace(Symbol sym, Object o, Object v){
    1.85 +    if (o instanceof Var)
    1.86 +        {
    1.87 +        Namespace ns = ((Var)o).ns;
    1.88 +        if (ns == this)
    1.89 +            return;
    1.90 +        if (ns != RT.CLOJURE_NS)
    1.91 +            throw new IllegalStateException(sym + " already refers to: " + o + " in namespace: " + name);
    1.92 +        }
    1.93 +	RT.errPrintWriter().println("WARNING: " + sym + " already refers to: " + o + " in namespace: " + name
    1.94 +		+ ", being replaced by: " + v);
    1.95 +}
    1.96 +
    1.97 +Object reference(Symbol sym, Object val){
    1.98 +	if(sym.ns != null)
    1.99 +		{
   1.100 +		throw new IllegalArgumentException("Can't intern namespace-qualified symbol");
   1.101 +		}
   1.102 +	IPersistentMap map = getMappings();
   1.103 +	Object o;
   1.104 +	while((o = map.valAt(sym)) == null)
   1.105 +		{
   1.106 +		IPersistentMap newMap = map.assoc(sym, val);
   1.107 +		mappings.compareAndSet(map, newMap);
   1.108 +		map = getMappings();
   1.109 +		}
   1.110 +	if(o == val)
   1.111 +		return o;
   1.112 +
   1.113 +	warnOrFailOnReplace(sym, o, val);
   1.114 +
   1.115 +	while(!mappings.compareAndSet(map, map.assoc(sym, val)))
   1.116 +		map = getMappings();
   1.117 +
   1.118 +	return val;
   1.119 +
   1.120 +}
   1.121 +
   1.122 +public static boolean areDifferentInstancesOfSameClassName(Class cls1, Class cls2) {
   1.123 +    return (cls1 != cls2) && (cls1.getName().equals(cls2.getName()));
   1.124 +}
   1.125 +
   1.126 +Class referenceClass(Symbol sym, Class val){
   1.127 +    if(sym.ns != null)
   1.128 +        {
   1.129 +        throw new IllegalArgumentException("Can't intern namespace-qualified symbol");
   1.130 +        }
   1.131 +    IPersistentMap map = getMappings();
   1.132 +    Class c = (Class) map.valAt(sym);
   1.133 +    while((c == null) || (areDifferentInstancesOfSameClassName(c, val)))
   1.134 +        {
   1.135 +        IPersistentMap newMap = map.assoc(sym, val);
   1.136 +        mappings.compareAndSet(map, newMap);
   1.137 +        map = getMappings();
   1.138 +        c = (Class) map.valAt(sym);
   1.139 +        }
   1.140 +    if(c == val)
   1.141 +        return c;
   1.142 +
   1.143 +    throw new IllegalStateException(sym + " already refers to: " + c + " in namespace: " + name);
   1.144 +}
   1.145 +
   1.146 +public void unmap(Symbol sym) throws Exception{
   1.147 +	if(sym.ns != null)
   1.148 +		{
   1.149 +		throw new IllegalArgumentException("Can't unintern namespace-qualified symbol");
   1.150 +		}
   1.151 +	IPersistentMap map = getMappings();
   1.152 +	while(map.containsKey(sym))
   1.153 +		{
   1.154 +		IPersistentMap newMap = map.without(sym);
   1.155 +		mappings.compareAndSet(map, newMap);
   1.156 +		map = getMappings();
   1.157 +		}
   1.158 +}
   1.159 +
   1.160 +public Class importClass(Symbol sym, Class c){
   1.161 +	return referenceClass(sym, c);
   1.162 +
   1.163 +}
   1.164 +
   1.165 +public Class importClass(Class c){
   1.166 +	String n = c.getName();
   1.167 +	return importClass(Symbol.intern(n.substring(n.lastIndexOf('.') + 1)), c);
   1.168 +}
   1.169 +
   1.170 +public Var refer(Symbol sym, Var var){
   1.171 +	return (Var) reference(sym, var);
   1.172 +
   1.173 +}
   1.174 +
   1.175 +public static Namespace findOrCreate(Symbol name){
   1.176 +	Namespace ns = namespaces.get(name);
   1.177 +	if(ns != null)
   1.178 +		return ns;
   1.179 +	Namespace newns = new Namespace(name);
   1.180 +	ns = namespaces.putIfAbsent(name, newns);
   1.181 +	return ns == null ? newns : ns;
   1.182 +}
   1.183 +
   1.184 +public static Namespace remove(Symbol name){
   1.185 +	if(name.equals(RT.CLOJURE_NS.name))
   1.186 +		throw new IllegalArgumentException("Cannot remove clojure namespace");
   1.187 +	return namespaces.remove(name);
   1.188 +}
   1.189 +
   1.190 +public static Namespace find(Symbol name){
   1.191 +	return namespaces.get(name);
   1.192 +}
   1.193 +
   1.194 +public Object getMapping(Symbol name){
   1.195 +	return mappings.get().valAt(name);
   1.196 +}
   1.197 +
   1.198 +public Var findInternedVar(Symbol symbol){
   1.199 +	Object o = mappings.get().valAt(symbol);
   1.200 +	if(o != null && o instanceof Var && ((Var) o).ns == this)
   1.201 +		return (Var) o;
   1.202 +	return null;
   1.203 +}
   1.204 +
   1.205 +
   1.206 +public IPersistentMap getAliases(){
   1.207 +	return aliases.get();
   1.208 +}
   1.209 +
   1.210 +public Namespace lookupAlias(Symbol alias){
   1.211 +	IPersistentMap map = getAliases();
   1.212 +	return (Namespace) map.valAt(alias);
   1.213 +}
   1.214 +
   1.215 +public void addAlias(Symbol alias, Namespace ns){
   1.216 +	if (alias == null || ns == null)
   1.217 +		throw new NullPointerException("Expecting Symbol + Namespace");
   1.218 +	IPersistentMap map = getAliases();
   1.219 +	while(!map.containsKey(alias))
   1.220 +		{
   1.221 +		IPersistentMap newMap = map.assoc(alias, ns);
   1.222 +		aliases.compareAndSet(map, newMap);
   1.223 +		map = getAliases();
   1.224 +		}
   1.225 +	// you can rebind an alias, but only to the initially-aliased namespace.
   1.226 +	if(!map.valAt(alias).equals(ns))
   1.227 +		throw new IllegalStateException("Alias " + alias + " already exists in namespace "
   1.228 +		                                   + name + ", aliasing " + map.valAt(alias));
   1.229 +}
   1.230 +
   1.231 +public void removeAlias(Symbol alias) throws Exception{
   1.232 +	IPersistentMap map = getAliases();
   1.233 +	while(map.containsKey(alias))
   1.234 +		{
   1.235 +		IPersistentMap newMap = map.without(alias);
   1.236 +		aliases.compareAndSet(map, newMap);
   1.237 +		map = getAliases();
   1.238 +		}
   1.239 +}
   1.240 +
   1.241 +private Object readResolve() throws ObjectStreamException {
   1.242 +    // ensures that serialized namespaces are "deserialized" to the
   1.243 +    // namespace in the present runtime
   1.244 +    return findOrCreate(name);
   1.245 +}
   1.246 +}