/**

* 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 Nov 2, 2009 */

package clojure.lang;

public final class KeywordLookupSite implements ILookupSite, ILookupThunk{

final Keyword k;

public KeywordLookupSite(Keyword k){

this.k = k;

}

public ILookupThunk fault(Object target){

if(target instanceof IKeywordLookup)

{

return install(target);

}

else if(target instanceof ILookup)

{

return ilookupThunk(target.getClass());

}

return this;

}

public Object get(Object target){

if(target instanceof IKeywordLookup || target instanceof ILookup)

return this;

return RT.get(target,k);

}

private ILookupThunk ilookupThunk(final Class c){

return new ILookupThunk(){

public Object get(Object target){

if(target != null && target.getClass() == c)

return ((ILookup) target).valAt(k);

return this;

}

};

}

private ILookupThunk install(Object target){

ILookupThunk t = ((IKeywordLookup)target).getLookupThunk(k);

if(t != null)

return t;

return ilookupThunk(target.getClass());

}

}