Simplify lazy-while and lazy-until constructs

db4
Samuel Tardieu 2007-12-27 03:36:38 +01:00
parent 4eb7aad50b
commit 0bf5c6bf0f
1 changed files with 7 additions and 10 deletions

View File

@ -211,17 +211,17 @@ TUPLE: lazy-until cons quot ;
C: <lazy-until> lazy-until
: luntil ( list quot -- result )
<lazy-until> ;
over nil? [ drop ] [ <lazy-until> ] if ;
M: lazy-until car ( lazy-until -- car )
lazy-until-cons car ;
M: lazy-until cdr ( lazy-until -- cdr )
[ lazy-until-cons uncons ] keep lazy-until-quot
rot over call [ 2drop nil ] [ luntil ] if ;
[ lazy-until-cons uncons swap ] keep lazy-until-quot tuck call
[ 2drop nil ] [ luntil ] if ;
M: lazy-until nil? ( lazy-until -- bool )
lazy-until-cons nil? ;
drop f ;
M: lazy-until list? ( lazy-until -- bool )
drop t ;
@ -231,19 +231,16 @@ TUPLE: lazy-while cons quot ;
C: <lazy-while> lazy-while
: lwhile ( list quot -- result )
<lazy-while>
;
over nil? [ drop ] [ <lazy-while> ] if ;
M: lazy-while car ( lazy-while -- car )
lazy-while-cons car ;
M: lazy-while cdr ( lazy-while -- cdr )
dup lazy-while-cons cdr dup nil?
[ 2drop nil ] [ swap lazy-while-quot lwhile ] if ;
[ lazy-while-cons cdr ] keep lazy-while-quot lwhile ;
M: lazy-while nil? ( lazy-while -- bool )
dup lazy-while-cons nil?
[ nip ] [ [ car ] keep lazy-while-quot call not ] if* ;
[ car ] keep lazy-while-quot call not ;
M: lazy-while list? ( lazy-while -- bool )
drop t ;