Revert "hash-sets,hashtables: improved key@ word"

This reverts commit 70c7f9e029.

core/hash-sets/hash-sets-tests.factor

@@ -1,17 +1,7 @@
 ! Copyright (C) 2010 Daniel Ehrenberg
 ! See http://factorcode.org/license.txt for BSD license.
-USING: accessors arrays fry hash-sets hash-sets.private kernel math
-prettyprint sequences sets sorting tools.test ;
-FROM: hashtables.private => tombstone ;
-
-! key@
-{
-    { { T{ tombstone } T{ tombstone } } f f }
-    { { T{ tombstone } 123 } 1 t }
-} [
-    "hi" 0 <hash-set> key@ 3array
-    123 HS{ 123 } key@ 3array
-] unit-test
+USING: accessors fry hash-sets kernel math prettyprint sequences
+sets sorting tools.test ;
 
 { { 1 2 3 } } [ HS{ 1 2 3 } members natural-sort ] unit-test
 

core/hash-sets/hash-sets.factor

@@ -35,7 +35,8 @@ TUPLE: hash-set
     ] if ; inline recursive
 
 : key@ ( key hash -- array n ? )
-    array>> 2dup hash@ 0 (key@) ; inline
+    array>> dup length>> 0 eq?
+    [ no-key ] [ 2dup hash@ 0 (key@) ] if ; inline
 
 : <hash-array> ( n -- array )
     3 * 1 + 2/ next-power-of-2 +empty+ <array> ; inline

core/hashtables/hashtables.factor

@@ -38,7 +38,8 @@ TUPLE: hashtable
     ] if ; inline recursive
 
 : key@ ( key hash -- array n ? )
-    array>> 2dup hash@ 0 (key@) ; inline
+    array>> dup length>> 0 eq?
+    [ no-key ] [ 2dup hash@ 0 (key@) ] if ; inline
 
 : <hash-array> ( n -- array )
     3 * 1 + 2/ next-power-of-2 2 * +empty+ <array> ; inline