diff --git a/basis/regexp/ast/ast.factor b/basis/regexp/ast/ast.factor
index be657227e5..2916ef7c32 100644
--- a/basis/regexp/ast/ast.factor
+++ b/basis/regexp/ast/ast.factor
@@ -21,12 +21,12 @@ CONSTANT: epsilon T{ tagged-epsilon { tag t } }
 TUPLE: concatenation first second ;
 
 : <concatenation> ( seq -- concatenation )
-    [ epsilon ] [ unclip [ concatenation boa ] reduce ] if-empty ;
+    [ epsilon ] [ [ ] [ concatenation boa ] map-reduce ] if-empty ;
 
 TUPLE: alternation first second ;
 
 : <alternation> ( seq -- alternation )
-    unclip [ alternation boa ] reduce ;
+    [ ] [ alternation boa ] map-reduce ;
 
 TUPLE: star term ;
 C: <star> star
diff --git a/basis/regexp/transition-tables/transition-tables.factor b/basis/regexp/transition-tables/transition-tables.factor
index 3c33ae8846..f452e3d24a 100644
--- a/basis/regexp/transition-tables/transition-tables.factor
+++ b/basis/regexp/transition-tables/transition-tables.factor
@@ -11,12 +11,7 @@ TUPLE: transition-table transitions start-state final-states ;
         H{ } clone >>transitions
         H{ } clone >>final-states ;
 
-: maybe-initialize-key ( key hashtable -- )
-    ! Why do we have to do this?
-    2dup key? [ 2drop ] [ [ H{ } clone ] 2dip set-at ] if ;
-
 :: (set-transition) ( from to obj hash -- )
-    to condition? [ to hash maybe-initialize-key ] unless
     from hash at
     [ [ to obj ] dip set-at ]
     [ to obj associate from hash set-at ] if* ;
@@ -25,7 +20,6 @@ TUPLE: transition-table transitions start-state final-states ;
     transitions>> (set-transition) ;
 
 :: (add-transition) ( from to obj hash -- )
-    to hash maybe-initialize-key
     from hash at
     [ [ to obj ] dip push-at ]
     [ to 1vector obj associate from hash set-at ] if* ;
diff --git a/extra/robots/robots.factor b/extra/robots/robots.factor
index 1b2422f06e..242aa1dea2 100644
--- a/extra/robots/robots.factor
+++ b/extra/robots/robots.factor
@@ -3,11 +3,21 @@
 USING: accessors http.client kernel unicode.categories
 sequences urls splitting combinators splitting.monotonic
 combinators.short-circuit assocs unicode.case arrays
-math.parser calendar.format make ;
+math.parser calendar.format make fry present globs
+multiline regexp.combinators regexp ;
 IN: robots
 
 ! visit-time is GMT, request-rate is pages/second 
 ! crawl-rate is seconds
+
+TUPLE: robots site sitemap rules rules-quot ;
+
+: <robots> ( site sitemap rules -- robots )
+    \ robots new
+        swap >>rules
+        swap >>sitemap
+        swap >>site ;
+
 TUPLE: rules user-agents allows disallows
 visit-time request-rate crawl-delay unknowns ;
 
@@ -40,8 +50,8 @@ visit-time request-rate crawl-delay unknowns ;
         H{ } clone >>unknowns ;
 
 : add-user-agent ( rules agent -- rules ) over user-agents>> push ;
-: add-allow ( rules allow -- rules ) over allows>> push ;
-: add-disallow ( rules disallow -- rules ) over disallows>> push ;
+: add-allow ( rules allow -- rules ) >url over allows>> push ;
+: add-disallow ( rules disallow -- rules ) >url over disallows>> push ;
 
 : parse-robots.txt-line ( rules seq -- rules )
     first2 swap {
@@ -57,12 +67,26 @@ visit-time request-rate crawl-delay unknowns ;
         [ pick unknowns>> push-at ]
     } case ;
 
+: derive-urls ( url seq -- seq' )
+    [ derive-url present ] with { } map-as ;
+
+: robot-rules-quot ( robots -- quot )
+    [
+        [ site>> ] [ rules>> allows>> ] bi
+        derive-urls [ <glob> ] map
+        <or>
+    ] [
+        [ site>> ] [ rules>> disallows>> ] bi
+        derive-urls [ <glob> ] map <and> <not>
+    ] bi 2array <or> '[ _ matches? ] ;
+
 PRIVATE>
 
 : parse-robots.txt ( string -- sitemaps rules-seq )
     normalize-robots.txt [
         [ <rules> dup ] dip [ parse-robots.txt-line drop ] with each
-    ] map ;
+    ] map first ;
 
-: robots ( url -- sitemaps rules-seq )
-    get-robots.txt nip parse-robots.txt ;
+: robots ( url -- robots )
+    >url
+    dup get-robots.txt nip parse-robots.txt <robots> ;