1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/clojure/lang/Var.java	Sat Aug 21 06:25:44 2010 -0400
     1.3 @@ -0,0 +1,497 @@
     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 Jul 31, 2007 */
    1.15 +
    1.16 +package clojure.lang;
    1.17 +
    1.18 +import java.util.concurrent.atomic.AtomicInteger;
    1.19 +
    1.20 +
    1.21 +public final class Var extends ARef implements IFn, IRef, Settable{
    1.22 +
    1.23 +
    1.24 +static class Frame{
    1.25 +	//Var->Box
    1.26 +	Associative bindings;
    1.27 +	//Var->val
    1.28 +	Associative frameBindings;
    1.29 +	Frame prev;
    1.30 +
    1.31 +
    1.32 +	public Frame(){
    1.33 +		this(PersistentHashMap.EMPTY, PersistentHashMap.EMPTY, null);
    1.34 +	}
    1.35 +
    1.36 +	public Frame(Associative frameBindings, Associative bindings, Frame prev){
    1.37 +		this.frameBindings = frameBindings;
    1.38 +		this.bindings = bindings;
    1.39 +		this.prev = prev;
    1.40 +	}
    1.41 +}
    1.42 +
    1.43 +static ThreadLocal<Frame> dvals = new ThreadLocal<Frame>(){
    1.44 +
    1.45 +	protected Frame initialValue(){
    1.46 +		return new Frame();
    1.47 +	}
    1.48 +};
    1.49 +
    1.50 +static Keyword privateKey = Keyword.intern(null, "private");
    1.51 +static IPersistentMap privateMeta = new PersistentArrayMap(new Object[]{privateKey, Boolean.TRUE});
    1.52 +static Keyword macroKey = Keyword.intern(null, "macro");
    1.53 +static Keyword nameKey = Keyword.intern(null, "name");
    1.54 +static Keyword nsKey = Keyword.intern(null, "ns");
    1.55 +//static Keyword tagKey = Keyword.intern(null, "tag");
    1.56 +
    1.57 +volatile Object root;
    1.58 +transient final AtomicInteger count;
    1.59 +public final Symbol sym;
    1.60 +public final Namespace ns;
    1.61 +
    1.62 +//IPersistentMap _meta;
    1.63 +
    1.64 +public static Var intern(Namespace ns, Symbol sym, Object root){
    1.65 +	return intern(ns, sym, root, true);
    1.66 +}
    1.67 +
    1.68 +public static Var intern(Namespace ns, Symbol sym, Object root, boolean replaceRoot){
    1.69 +	Var dvout = ns.intern(sym);
    1.70 +	if(!dvout.hasRoot() || replaceRoot)
    1.71 +		dvout.bindRoot(root);
    1.72 +	return dvout;
    1.73 +}
    1.74 +
    1.75 +
    1.76 +public String toString(){
    1.77 +	if(ns != null)
    1.78 +		return "#'" + ns.name + "/" + sym;
    1.79 +	return "#<Var: " + (sym != null ? sym.toString() : "--unnamed--") + ">";
    1.80 +}
    1.81 +
    1.82 +public static Var find(Symbol nsQualifiedSym){
    1.83 +	if(nsQualifiedSym.ns == null)
    1.84 +		throw new IllegalArgumentException("Symbol must be namespace-qualified");
    1.85 +	Namespace ns = Namespace.find(Symbol.create(nsQualifiedSym.ns));
    1.86 +	if(ns == null)
    1.87 +		throw new IllegalArgumentException("No such namespace: " + nsQualifiedSym.ns);
    1.88 +	return ns.findInternedVar(Symbol.create(nsQualifiedSym.name));
    1.89 +}
    1.90 +
    1.91 +public static Var intern(Symbol nsName, Symbol sym){
    1.92 +	Namespace ns = Namespace.findOrCreate(nsName);
    1.93 +	return intern(ns, sym);
    1.94 +}
    1.95 +
    1.96 +public static Var internPrivate(String nsName, String sym){
    1.97 +	Namespace ns = Namespace.findOrCreate(Symbol.intern(nsName));
    1.98 +	Var ret = intern(ns, Symbol.intern(sym));
    1.99 +	ret.setMeta(privateMeta);
   1.100 +	return ret;
   1.101 +}
   1.102 +
   1.103 +public static Var intern(Namespace ns, Symbol sym){
   1.104 +	return ns.intern(sym);
   1.105 +}
   1.106 +
   1.107 +
   1.108 +public static Var create(){
   1.109 +	return new Var(null, null);
   1.110 +}
   1.111 +
   1.112 +public static Var create(Object root){
   1.113 +	return new Var(null, null, root);
   1.114 +}
   1.115 +
   1.116 +Var(Namespace ns, Symbol sym){
   1.117 +	this.ns = ns;
   1.118 +	this.sym = sym;
   1.119 +	this.count = new AtomicInteger();
   1.120 +	this.root = dvals;  //use dvals as magic not-bound value
   1.121 +	setMeta(PersistentHashMap.EMPTY);
   1.122 +}
   1.123 +
   1.124 +Var(Namespace ns, Symbol sym, Object root){
   1.125 +	this(ns, sym);
   1.126 +	this.root = root;
   1.127 +}
   1.128 +
   1.129 +public boolean isBound(){
   1.130 +	return hasRoot() || (count.get() > 0 && dvals.get().bindings.containsKey(this));
   1.131 +}
   1.132 +
   1.133 +final public Object get(){
   1.134 +	if(count.get() == 0 && root != dvals)
   1.135 +		return root;
   1.136 +	return deref();
   1.137 +}
   1.138 +
   1.139 +final public Object deref(){
   1.140 +	Box b = getThreadBinding();
   1.141 +	if(b != null)
   1.142 +		return b.val;
   1.143 +	if(hasRoot())
   1.144 +		return root;
   1.145 +	throw new IllegalStateException(String.format("Var %s/%s is unbound.", ns, sym));
   1.146 +}
   1.147 +
   1.148 +public void setValidator(IFn vf){
   1.149 +	if(hasRoot())
   1.150 +		validate(vf, getRoot());
   1.151 +	validator = vf;
   1.152 +}
   1.153 +
   1.154 +public Object alter(IFn fn, ISeq args) throws Exception{
   1.155 +	set(fn.applyTo(RT.cons(deref(), args)));
   1.156 +	return this;
   1.157 +}
   1.158 +
   1.159 +public Object set(Object val){
   1.160 +	validate(getValidator(), val);
   1.161 +	Box b = getThreadBinding();
   1.162 +	if(b != null)
   1.163 +		return (b.val = val);
   1.164 +	//jury still out on this
   1.165 +//	if(hasRoot())
   1.166 +//		{
   1.167 +//		bindRoot(val);
   1.168 +//		return val;
   1.169 +//		}
   1.170 +	throw new IllegalStateException(String.format("Can't change/establish root binding of: %s with set", sym));
   1.171 +}
   1.172 +
   1.173 +public Object doSet(Object val) throws Exception {
   1.174 +    return set(val);
   1.175 +    }
   1.176 +
   1.177 +public Object doReset(Object val) throws Exception {
   1.178 +    bindRoot(val);
   1.179 +    return val;
   1.180 +    }
   1.181 +
   1.182 +public void setMeta(IPersistentMap m) {
   1.183 +    //ensure these basis keys
   1.184 +    resetMeta(m.assoc(nameKey, sym).assoc(nsKey, ns));
   1.185 +}
   1.186 +
   1.187 +public void setMacro() {
   1.188 +    try
   1.189 +        {
   1.190 +        alterMeta(assoc, RT.list(macroKey, RT.T));
   1.191 +        }
   1.192 +    catch (Exception e)
   1.193 +        {
   1.194 +        throw new RuntimeException(e);
   1.195 +        }
   1.196 +}
   1.197 +
   1.198 +public boolean isMacro(){
   1.199 +	return RT.booleanCast(meta().valAt(macroKey));
   1.200 +}
   1.201 +
   1.202 +//public void setExported(boolean state){
   1.203 +//	_meta = _meta.assoc(privateKey, state);
   1.204 +//}
   1.205 +
   1.206 +public boolean isPublic(){
   1.207 +	return !RT.booleanCast(meta().valAt(privateKey));
   1.208 +}
   1.209 +
   1.210 +public Object getRoot(){
   1.211 +	if(hasRoot())
   1.212 +		return root;
   1.213 +	throw new IllegalStateException(String.format("Var %s/%s is unbound.", ns, sym));
   1.214 +}
   1.215 +
   1.216 +public Object getRawRoot(){
   1.217 +		return root;
   1.218 +}
   1.219 +
   1.220 +public Object getTag(){
   1.221 +	return meta().valAt(RT.TAG_KEY);
   1.222 +}
   1.223 +
   1.224 +public void setTag(Symbol tag) {
   1.225 +    try
   1.226 +        {
   1.227 +        alterMeta(assoc, RT.list(RT.TAG_KEY, tag));
   1.228 +        }
   1.229 +    catch (Exception e)
   1.230 +        {
   1.231 +        throw new RuntimeException(e);
   1.232 +        }
   1.233 +}
   1.234 +
   1.235 +final public boolean hasRoot(){
   1.236 +	return root != dvals;
   1.237 +}
   1.238 +
   1.239 +//binding root always clears macro flag
   1.240 +synchronized public void bindRoot(Object root){
   1.241 +	validate(getValidator(), root);
   1.242 +	Object oldroot = hasRoot()?this.root:null;
   1.243 +	this.root = root;
   1.244 +    try
   1.245 +        {
   1.246 +        alterMeta(dissoc, RT.list(macroKey));
   1.247 +        }
   1.248 +    catch (Exception e)
   1.249 +        {
   1.250 +        throw new RuntimeException(e);
   1.251 +        }
   1.252 +    notifyWatches(oldroot,this.root);
   1.253 +}
   1.254 +
   1.255 +synchronized void swapRoot(Object root){
   1.256 +	validate(getValidator(), root);
   1.257 +	Object oldroot = hasRoot()?this.root:null;
   1.258 +	this.root = root;
   1.259 +    notifyWatches(oldroot,root);
   1.260 +}
   1.261 +
   1.262 +synchronized public void unbindRoot(){
   1.263 +	this.root = dvals;
   1.264 +}
   1.265 +
   1.266 +synchronized public void commuteRoot(IFn fn) throws Exception{
   1.267 +	Object newRoot = fn.invoke(root);
   1.268 +	validate(getValidator(), newRoot);
   1.269 +	Object oldroot = getRoot();
   1.270 +	this.root = newRoot;
   1.271 +    notifyWatches(oldroot,newRoot);
   1.272 +}
   1.273 +
   1.274 +synchronized public Object alterRoot(IFn fn, ISeq args) throws Exception{
   1.275 +	Object newRoot = fn.applyTo(RT.cons(root, args));
   1.276 +	validate(getValidator(), newRoot);
   1.277 +	Object oldroot = getRoot();
   1.278 +	this.root = newRoot;
   1.279 +    notifyWatches(oldroot,newRoot);
   1.280 +	return newRoot;
   1.281 +}
   1.282 +
   1.283 +public static void pushThreadBindings(Associative bindings){
   1.284 +	Frame f = dvals.get();
   1.285 +	Associative bmap = f.bindings;
   1.286 +	for(ISeq bs = bindings.seq(); bs != null; bs = bs.next())
   1.287 +		{
   1.288 +		IMapEntry e = (IMapEntry) bs.first();
   1.289 +		Var v = (Var) e.key();
   1.290 +		v.validate(v.getValidator(), e.val());
   1.291 +		v.count.incrementAndGet();
   1.292 +		bmap = bmap.assoc(v, new Box(e.val()));
   1.293 +		}
   1.294 +	dvals.set(new Frame(bindings, bmap, f));
   1.295 +}
   1.296 +
   1.297 +public static void popThreadBindings(){
   1.298 +	Frame f = dvals.get();
   1.299 +	if(f.prev == null)
   1.300 +		throw new IllegalStateException("Pop without matching push");
   1.301 +	for(ISeq bs = RT.keys(f.frameBindings); bs != null; bs = bs.next())
   1.302 +		{
   1.303 +		Var v = (Var) bs.first();
   1.304 +		v.count.decrementAndGet();
   1.305 +		}
   1.306 +	dvals.set(f.prev);
   1.307 +}
   1.308 +
   1.309 +public static void releaseThreadBindings(){
   1.310 +	Frame f = dvals.get();
   1.311 +	if(f.prev == null)
   1.312 +		throw new IllegalStateException("Release without full unwind");
   1.313 +	for(ISeq bs = RT.keys(f.bindings); bs != null; bs = bs.next())
   1.314 +		{
   1.315 +		Var v = (Var) bs.first();
   1.316 +		v.count.decrementAndGet();
   1.317 +		}
   1.318 +	dvals.set(null);
   1.319 +}
   1.320 +
   1.321 +public static Associative getThreadBindings(){
   1.322 +	Frame f = dvals.get();
   1.323 +	IPersistentMap ret = PersistentHashMap.EMPTY;
   1.324 +	for(ISeq bs = f.bindings.seq(); bs != null; bs = bs.next())
   1.325 +		{
   1.326 +		IMapEntry e = (IMapEntry) bs.first();
   1.327 +		Var v = (Var) e.key();
   1.328 +		Box b = (Box) e.val();
   1.329 +		ret = ret.assoc(v, b.val);
   1.330 +		}
   1.331 +	return ret;
   1.332 +}
   1.333 +
   1.334 +public final Box getThreadBinding(){
   1.335 +	if(count.get() > 0)
   1.336 +		{
   1.337 +		IMapEntry e = dvals.get().bindings.entryAt(this);
   1.338 +		if(e != null)
   1.339 +			return (Box) e.val();
   1.340 +		}
   1.341 +	return null;
   1.342 +}
   1.343 +
   1.344 +final public IFn fn(){
   1.345 +	return (IFn) deref();
   1.346 +}
   1.347 +
   1.348 +public Object call() throws Exception{
   1.349 +	return invoke();
   1.350 +}
   1.351 +
   1.352 +public void run(){
   1.353 +	try
   1.354 +		{
   1.355 +		invoke();
   1.356 +		}
   1.357 +	catch(Exception e)
   1.358 +		{
   1.359 +		throw new RuntimeException(e);
   1.360 +		}
   1.361 +}
   1.362 +
   1.363 +public Object invoke() throws Exception{
   1.364 +	return fn().invoke();
   1.365 +}
   1.366 +
   1.367 +public Object invoke(Object arg1) throws Exception{
   1.368 +	return fn().invoke(arg1);
   1.369 +}
   1.370 +
   1.371 +public Object invoke(Object arg1, Object arg2) throws Exception{
   1.372 +	return fn().invoke(arg1, arg2);
   1.373 +}
   1.374 +
   1.375 +public Object invoke(Object arg1, Object arg2, Object arg3) throws Exception{
   1.376 +	return fn().invoke(arg1, arg2, arg3);
   1.377 +}
   1.378 +
   1.379 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4) throws Exception{
   1.380 +	return fn().invoke(arg1, arg2, arg3, arg4);
   1.381 +}
   1.382 +
   1.383 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5) throws Exception{
   1.384 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5);
   1.385 +}
   1.386 +
   1.387 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6) throws Exception{
   1.388 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6);
   1.389 +}
   1.390 +
   1.391 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7)
   1.392 +		throws Exception{
   1.393 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7);
   1.394 +}
   1.395 +
   1.396 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.397 +                     Object arg8) throws Exception{
   1.398 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
   1.399 +}
   1.400 +
   1.401 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.402 +                     Object arg8, Object arg9) throws Exception{
   1.403 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9);
   1.404 +}
   1.405 +
   1.406 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.407 +                     Object arg8, Object arg9, Object arg10) throws Exception{
   1.408 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10);
   1.409 +}
   1.410 +
   1.411 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.412 +                     Object arg8, Object arg9, Object arg10, Object arg11) throws Exception{
   1.413 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11);
   1.414 +}
   1.415 +
   1.416 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.417 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12) throws Exception{
   1.418 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12);
   1.419 +}
   1.420 +
   1.421 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.422 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13)
   1.423 +		throws Exception{
   1.424 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13);
   1.425 +}
   1.426 +
   1.427 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.428 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13, Object arg14)
   1.429 +		throws Exception{
   1.430 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13, arg14);
   1.431 +}
   1.432 +
   1.433 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.434 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13, Object arg14,
   1.435 +                     Object arg15) throws Exception{
   1.436 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13, arg14, arg15);
   1.437 +}
   1.438 +
   1.439 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.440 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13, Object arg14,
   1.441 +                     Object arg15, Object arg16) throws Exception{
   1.442 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13, arg14, arg15,
   1.443 +	                   arg16);
   1.444 +}
   1.445 +
   1.446 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.447 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13, Object arg14,
   1.448 +                     Object arg15, Object arg16, Object arg17) throws Exception{
   1.449 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13, arg14, arg15,
   1.450 +	                   arg16, arg17);
   1.451 +}
   1.452 +
   1.453 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.454 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13, Object arg14,
   1.455 +                     Object arg15, Object arg16, Object arg17, Object arg18) throws Exception{
   1.456 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13, arg14, arg15,
   1.457 +	                   arg16, arg17, arg18);
   1.458 +}
   1.459 +
   1.460 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.461 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13, Object arg14,
   1.462 +                     Object arg15, Object arg16, Object arg17, Object arg18, Object arg19) throws Exception{
   1.463 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13, arg14, arg15,
   1.464 +	                   arg16, arg17, arg18, arg19);
   1.465 +}
   1.466 +
   1.467 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.468 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13, Object arg14,
   1.469 +                     Object arg15, Object arg16, Object arg17, Object arg18, Object arg19, Object arg20)
   1.470 +		throws Exception{
   1.471 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13, arg14, arg15,
   1.472 +	                   arg16, arg17, arg18, arg19, arg20);
   1.473 +}
   1.474 +
   1.475 +public Object invoke(Object arg1, Object arg2, Object arg3, Object arg4, Object arg5, Object arg6, Object arg7,
   1.476 +                     Object arg8, Object arg9, Object arg10, Object arg11, Object arg12, Object arg13, Object arg14,
   1.477 +                     Object arg15, Object arg16, Object arg17, Object arg18, Object arg19, Object arg20,
   1.478 +                     Object... args)
   1.479 +		throws Exception{
   1.480 +	return fn().invoke(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11, arg12, arg13, arg14, arg15,
   1.481 +	                   arg16, arg17, arg18, arg19, arg20, args);
   1.482 +}
   1.483 +
   1.484 +public Object applyTo(ISeq arglist) throws Exception{
   1.485 +	return AFn.applyToHelper(this, arglist);
   1.486 +}
   1.487 +
   1.488 +static IFn assoc = new AFn(){
   1.489 +    @Override
   1.490 +    public Object invoke(Object m, Object k, Object v) throws Exception {
   1.491 +        return RT.assoc(m, k, v);
   1.492 +    }
   1.493 +};
   1.494 +static IFn dissoc = new AFn() {
   1.495 +    @Override
   1.496 +    public Object invoke(Object c, Object k) throws Exception {
   1.497 +        return RT.dissoc(c, k);
   1.498 +    }
   1.499 +};
   1.500 +}