sequences.extras: adding slice-when (non-destructive split-when).

db4
John Benediktsson 2012-04-19 16:41:44 -07:00
parent 449814a387
commit 5b83dc2e90
2 changed files with 13 additions and 1 deletions

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@ -1,4 +1,5 @@
USING: ascii kernel make math sequences sequences.extras tools.test ;
USING: ascii kernel make math sequences sequences.extras strings
tools.test ;
IN: sequences.extras.tests
@ -45,3 +46,6 @@ IN: sequences.extras.tests
{ " a b c d e " }
[ " a b c d e " [ blank? ] " " collapse ] unit-test
{ { "hello," " " "world!" " " " " } }
[ "hello, world! " [ blank? ] slice-when [ >string ] map ] unit-test

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@ -95,3 +95,11 @@ IN: sequences.extras
[ [ first empty? ] dip [ prepend ] curry when ]
[ [ last empty? ] dip [ append ] curry when ]
2tri ; inline
:: slice-when ( seq quot: ( elt -- ? ) -- seq' )
seq length :> len
0 [ len dupd < ] [
dup seq quot find-from drop
[ 2dup = [ 1 + ] when ] [ len ] if*
[ seq <slice> ] keep len or swap
] produce nip ; inline