removing some uses of at* in favor of at, simplifying code

basis/regexp/regexp-tests.factor

@@ -331,4 +331,3 @@ IN: regexp-tests
 [ { 0 3 } ] [ "abc" "(ab|a)(bc)?" <regexp> first-match ] unit-test
 
 [ { 23 24 } ] [ "aaaaaaaaaaaaaaaaaaaaaaab" "((a*)*b)*b" <regexp> first-match ] unit-test
-

basis/regexp/regexp.factor

@@ -92,7 +92,6 @@ IN: regexp
     reversed-regexp initial-option
     construct-regexp ;
 
-
 : parsing-regexp ( accum end -- accum )
     lexer get dup skip-blank
     [ [ index-from dup 1+ swap ] 2keep swapd subseq swap ] change-lexer-column
@@ -112,7 +111,6 @@ IN: regexp
 : R{ CHAR: } parsing-regexp ; parsing
 : R| CHAR: | parsing-regexp ; parsing
 
-
 : find-regexp-syntax ( string -- prefix suffix )
     {
         { "R/ "  "/"  }

basis/regexp/traversal/traversal.factor

@@ -2,7 +2,8 @@
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors assocs combinators kernel math math.ranges
 quotations sequences regexp.parser regexp.classes fry arrays
-combinators.short-circuit regexp.utils prettyprint regexp.nfa ;
+combinators.short-circuit regexp.utils prettyprint regexp.nfa
+shuffle ;
 IN: regexp.traversal
 
 TUPLE: dfa-traverser
@@ -23,8 +24,7 @@ TUPLE: dfa-traverser
     [ dfa-table>> ] [ dfa-traversal-flags>> ] bi
     dfa-traverser new
         swap >>traversal-flags
-        swap [ start-state>> >>current-state ] keep
-        >>dfa-table
+        swap [ start-state>> >>current-state ] [ >>dfa-table ] bi
         swap >>text
         t >>traverse-forward
         0 >>start-index
@@ -116,7 +116,7 @@ M: capture-group-off flag-action ( dfa-traverser flag -- )
     V{ } clone >>matches ;
 
 : match-literal ( transition from-state table -- to-state/f )
-    transitions>> at* [ at ] [ 2drop f ] if ;
+    transitions>> at at ;
 
 : match-class ( transition from-state table -- to-state/f )
     transitions>> at* [
@@ -124,8 +124,7 @@ M: capture-group-off flag-action ( dfa-traverser flag -- )
     ] [ drop ] if ;
 
 : match-default ( transition from-state table -- to-state/f )
-    [ nip ] dip transitions>> at*
-    [ t swap at* [ ] [ drop f ] if ] [ drop f ] if ;
+    nipd transitions>> at t swap at ;
 
 : match-transition ( obj from-state dfa -- to-state/f )
     { [ match-literal ] [ match-class ] [ match-default ] } 3|| ;