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Rename {take,drop}-while' -> {take,drop}f'.

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Also, improve the tests a little.
This commit is contained in:
Eli Barzilay 2013-03-08 14:24:48 -05:00
parent 7d1ad25d6c
commit 2cdfe18beb
3 changed files with 28 additions and 27 deletions
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16
collects/racket/list.rkt
View File

@ -15,8 +15,8 @@
split-at
drop-right
take-right
take-while
drop-while
takef
dropf
split-at-right
append*
@ -153,11 +153,11 @@
(cons (car list) (loop (cdr list) (cdr lead)))
'())))
(define (take-while pred list)
(define (takef pred list)
(unless (procedure? pred)
(raise-argument-error 'take-while "procedure?" 0 pred list))
(raise-argument-error 'takef "procedure?" 0 pred list))
(unless (list? list)
(raise-argument-error 'take-while "list?" 1 pred list))
(raise-argument-error 'takef "list?" 1 pred list))
(let loop ([list list])
(if (null? list)
'()
@ -166,11 +166,11 @@
(cons x (loop (cdr list)))
'())))))
(define (drop-while pred list)
(define (dropf pred list)
(unless (procedure? pred)
(raise-argument-error 'drop-while "procedure?" 0 pred list))
(raise-argument-error 'dropf "procedure?" 0 pred list))
(unless (list? list)
(raise-argument-error 'drop-while "list?" 1 pred list))
(raise-argument-error 'dropf "list?" 1 pred list))
(let loop ([list list])
(cond [(null? list) '()]
[(pred (car list)) (loop (cdr list))]

12
collects/scribblings/reference/pairs.scrbl
View File

@ -821,7 +821,7 @@ Returns the same result as
except that it can be faster.}
@defproc[(take-while [pred procedure?] [lst list?])
@defproc[(takef [pred procedure?] [lst list?])
list?]{
Returns a fresh list whose elements are taken successively from
@racket[lst] as long as they satisfy @racket[pred]. The returned
@ -829,18 +829,18 @@ list includes up to, but not including, the first element in
@racket[lst] for which @racket[pred] returns @racket[#f].
@mz-examples[#:eval list-eval
(take-while even? '(2 4 5 8))
(take-while odd? '(2 4 6 8))
(dropf even? '(2 4 5 8))
(dropf odd? '(2 4 6 8))
]}
@defproc[(drop-while [pred procedure?] [lst list?])
@defproc[(dropf [pred procedure?] [lst list?])
list?]{
Returns a fresh list with elements successively removed from
@racket[lst] from the front as long as they satisfy @racket[pred].
@mz-examples[#:eval list-eval
(drop-while even? '(2 4 5 8))
(drop-while odd? '(2 4 6 8))
(dropf even? '(2 4 5 8))
(dropf odd? '(2 4 6 8))
]}
@defproc[(take-right [lst any/c] [pos exact-nonnegative-integer?]) any/c]{

27
collects/tests/racket/list.rktl
View File

@ -212,22 +212,23 @@
(err/rt-test (fun '(1) 2) exn:application:mismatch?)
(err/rt-test (fun '(1 2 . 3) 3) exn:application:mismatch?)))
;; ---------- take/drop-while ----------
;; ---------- takef/dropf ----------
(let ()
(define list-1 '(2 4 6 8 1 3 5))
(err/rt-test (take-while 5 '()) exn:application:mismatch?)
(err/rt-test (drop-while 5 '()) exn:application:mismatch?)
(err/rt-test (take-while even? 1) exn:application:mismatch?)
(err/rt-test (drop-while even? 1) exn:application:mismatch?)
(test '(2 4 6 8) take-while even? list-1)
(test '(1 3 5) drop-while even? list-1)
(test '() take-while odd? list-1)
(test list-1 drop-while odd? list-1)
(test list-1 take-while number? list-1)
(test '() drop-while number? list-1)
(test '() take-while list? '())
(test '() drop-while list? '()))
(err/rt-test (takef 5 '()) exn:application:mismatch?)
(err/rt-test (dropf 5 '()) exn:application:mismatch?)
(err/rt-test (takef even? 1) exn:application:mismatch?)
(err/rt-test (dropf even? 1) exn:application:mismatch?)
(define (t pred take-l drop-l)
(define l (append take-l drop-l))
(test take-l takef pred l)
(test drop-l dropf pred l))
(t even? '() '())
(t even? '(2 4) '(5 7))
(t even? '(2 4 6 8) '())
(t even? '() '(1 3 5))
(t symbol? '(a b c) '(1 2 3 x y z)))
;; ---------- append* ----------
(let ()