Move firstn to generalizations, clean it up a bit

extra/generalizations/generalizations-docs.factor

@@ -1,9 +1,21 @@
-! Copyright (C) 2007 Chris Double.
-! See http://factorcode.org/license.txt for BSD license.
 USING: help.syntax help.markup kernel sequences quotations
-math ;
+math arrays ;
 IN: generalizations
 
+HELP: narray
+{ $values { "n" integer } }
+{ $description "A generalization of " { $link 1array } ", "
+{ $link 2array } ", " { $link 3array } " and " { $link 4array } " "
+"that constructs an array from the top " { $snippet "n" } " elements of the stack."
+} ;
+
+HELP: firstn
+{ $values { "n" integer } }
+{ $description "A generalization of " { $link first } ", "
+{ $link first2 } ", " { $link first3 } " and " { $link first4 } " "
+"that pushes the first " { $snippet "n" } " elements of a sequence on the stack."
+} ;
+
 HELP: npick
 { $values { "n" integer } }
 { $description "A generalization of " { $link dup } ", "
@@ -119,6 +131,7 @@ ARTICLE: "generalizations" "Generalized shuffle words and combinators"
 "macros where the arity of the input quotations depends on an "
 "input parameter."
 { $subsection narray }
+{ $subsection firstn }
 { $subsection ndup }
 { $subsection npick }
 { $subsection nrot }

extra/generalizations/generalizations-tests.factor

@@ -32,3 +32,7 @@ IN: generalizations.tests
 [ [ dup 2^ 2array ] 5 napply ] must-infer
 
 [ { "xyc" "xyd" } ] [ "x" "y" { "c" "d" } [ 3append ] 2 nwith map ] unit-test
+
+[ 1 2 3 4 ] [ { 1 2 3 4 } 4 firstn ] unit-test
+[ ] [ { } 0 firstn ] unit-test
+[ "a" ] [ { "a" } 1 firstn ] unit-test

extra/generalizations/generalizations.factor

@@ -1,14 +1,20 @@
-! Copyright (C) 2007, 2008 Chris Double, Doug Coleman.
+! Copyright (C) 2007, 2008 Chris Double, Doug Coleman, Eduardo
+! Cavazos, Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: kernel sequences sequences.private namespaces math math.ranges
 combinators macros quotations fry locals arrays ;
 IN: generalizations
 
 MACRO: narray ( n -- quot )
-    dup [ f <array> ] curry
-    swap <reversed> [
-        [ swap [ set-nth-unsafe ] keep ] curry
-    ] map concat append ;
+    [ <reversed> ] [ '[ , f <array> ] ] bi
+    [ '[ @ [ , swap set-nth-unsafe ] keep ] ] reduce ;
+
+MACRO: firstn ( n -- )
+    dup zero? [ drop [ drop ] ] [
+        [ [ '[ , _ nth-unsafe ] ] map ]
+        [ 1- '[ , _ bounds-check 2drop ] ]
+        bi prefix '[ , cleave ]
+    ] if ;
 
 MACRO: npick ( n -- )
     1- dup saver [ dup ] rot [ r> swap ] n*quot 3append ;

extra/geo-ip/geo-ip.factor

@@ -1,5 +1,7 @@
+! Copyright (C) 2008 Slava Pestov.
+! See http://factorcode.org/license.txt for BSD license.
 USING: kernel sequences io.files io.launcher io.encodings.ascii
-io.streams.string http.client sequences.lib combinators
+io.streams.string http.client generalizations combinators
 math.parser math.vectors math.intervals interval-maps memoize
 csv accessors assocs strings math splitting grouping arrays ;
 IN: geo-ip

extra/namespaces/lib/lib.factor

@@ -2,7 +2,7 @@
 ! USING: kernel quotations namespaces sequences assocs.lib ;
 
 USING: kernel namespaces namespaces.private quotations sequences
-       assocs.lib math.parser math sequences.lib locals mirrors ;
+       assocs.lib math.parser math generalizations locals mirrors ;
 
 IN: namespaces.lib
 

extra/sequences/lib/lib-tests.factor

@@ -67,11 +67,6 @@ IN: sequences.lib.tests
 { 13 } [ 1 2 { 3 4 } [ + + ] 2 each-withn + ] unit-test
 [ { 910 911 912 } ] [ 10 900 3 [ + + ] map-with2 ] unit-test
 
-[ 1 2 3 4 ] [ { 1 2 3 4 } 4 firstn ] unit-test
-
-[ ] [ { } 0 firstn ] unit-test
-[ "a" ] [ { "a" } 1 firstn ] unit-test
-
 [ "empty" ] [ { } [ "not empty" ] [ "empty" ] if-seq ] unit-test
 [ { 1 } "not empty" ] [ { 1 } [ "not empty" ] [ "empty" ] if-seq ] unit-test
 

extra/sequences/lib/lib.factor

@@ -20,11 +20,6 @@ IN: sequences.lib
 
 : map-with2 ( obj obj list quot -- newseq ) 2 map-withn ; inline
 
-MACRO: firstn ( n -- )
-    [ [ swap nth ] curry [ keep ] curry ] map
-    concat >quotation
-    [ drop ] compose ;
-
 ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
 : each-percent ( seq quot -- )

extra/usa-cities/usa-cities.factor

@@ -1,6 +1,6 @@
 ! Copyright (C) 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: io.files io.encodings.ascii sequences sequences.lib
+USING: io.files io.encodings.ascii sequences generalizations
 math.parser combinators kernel memoize csv symbols summary
 words accessors math.order sorting ;
 IN: usa-cities