1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/clojure/lang/KeywordLookupSite.java	Sat Aug 21 06:25:44 2010 -0400
     1.3 @@ -0,0 +1,65 @@
     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 Nov 2, 2009 */
    1.15 +
    1.16 +package clojure.lang;
    1.17 +
    1.18 +public final class KeywordLookupSite implements ILookupSite, ILookupThunk{
    1.19 +
    1.20 +final int n;
    1.21 +final Keyword k;
    1.22 +
    1.23 +public KeywordLookupSite(int n, Keyword k){
    1.24 +	this.n = n;
    1.25 +	this.k = k;
    1.26 +}
    1.27 +
    1.28 +public Object fault(Object target, ILookupHost host){
    1.29 +	if(target instanceof IKeywordLookup)
    1.30 +		{
    1.31 +		return install(target, host);
    1.32 +		}
    1.33 +	else if(target instanceof ILookup)
    1.34 +		{
    1.35 +		host.swapThunk(n,ilookupThunk(target.getClass()));
    1.36 +		return ((ILookup) target).valAt(k);
    1.37 +		}
    1.38 +	host.swapThunk(n,this);
    1.39 +	return RT.get(target, k);
    1.40 +}
    1.41 +
    1.42 +public Object get(Object target){
    1.43 +	if(target instanceof IKeywordLookup || target instanceof ILookup)
    1.44 +		return this;
    1.45 +	return RT.get(target,k);
    1.46 +}
    1.47 +
    1.48 +private ILookupThunk ilookupThunk(final Class c){
    1.49 +	return new ILookupThunk(){
    1.50 +			public Object get(Object target){
    1.51 +				if(target != null && target.getClass() == c)
    1.52 +					return ((ILookup) target).valAt(k);
    1.53 +				return this;
    1.54 +			}
    1.55 +		};
    1.56 +}
    1.57 +
    1.58 +private Object install(Object target, ILookupHost host){
    1.59 +	ILookupThunk t = ((IKeywordLookup)target).getLookupThunk(k);
    1.60 +	if(t != null)
    1.61 +		{
    1.62 +		host.swapThunk(n,t);
    1.63 +		return t.get(target);
    1.64 +		}
    1.65 +	host.swapThunk(n,ilookupThunk(target.getClass()));
    1.66 +	return ((ILookup) target).valAt(k);
    1.67 +}
    1.68 +}