Improve sequence hash algorithm

core/combinators/combinators.factor

@@ -38,9 +38,7 @@ TUPLE: no-case ;
     pick 0 <= [ 3drop 0 ] [ rot 1- -rot call ] if ; inline
 
 M: sequence hashcode*
-    [
-        0 -rot [ hashcode* bitxor ] curry* each
-    ] recursive-hashcode ;
+    [ sequence-hashcode ] recursive-hashcode ;
 
 : alist>quot ( default assoc -- quot )
     [ rot \ if 3array append [ ] like ] assoc-each ;

core/sequences/sequences.factor

@@ -44,7 +44,7 @@ M: sequence lengthen 2dup length > [ set-length ] [ 2drop ] if ;
 TUPLE: bounds-error index seq ;
 
 : bounds-error ( n seq -- * )
-    \ bounds-error construct-boa throw ;
+    die \ bounds-error construct-boa throw ;
 
 : bounds-check ( n seq -- n seq )
     2dup bounds-check? [ bounds-error ] unless ; inline
@@ -666,3 +666,8 @@ PRIVATE>
 
 : infimum ( seq -- n ) dup first [ min ] reduce ;
 : supremum ( seq -- n ) dup first [ max ] reduce ;
+
+: sequence-hashcode ( n seq -- x )
+    0 -rot [
+        hashcode* >fixnum swap 31 fixnum*fast fixnum+fast
+    ] curry* each ; inline

core/strings/strings.factor

@@ -13,8 +13,7 @@ IN: strings
 : reset-string-hashcode f swap set-string-hashcode ; inline
 
 : rehash-string ( str -- )
-    dup 0 [ swap 31 fixnum*fast fixnum+fast ] reduce
-    swap set-string-hashcode ; inline
+    1 over sequence-hashcode swap set-string-hashcode ; inline
 
 PRIVATE>