pull/13/head
Sage Gerard 5 years ago
parent d559d568e1
commit e6d64fe7f1

@ -261,7 +261,7 @@
x))))
;; function to split tag out of txexpr
(define+provide+safe deleted-signal symbol? (gensym))
(define deleted-signal #f)
(define+provide+safe (splitf-txexpr tx pred [proc (λ (x) deleted-signal)])
((txexpr? procedure?) (procedure?) . ->* . (values txexpr? txexpr-elements?))
(unless (txexpr? tx)

@ -469,18 +469,12 @@ In practice, most @racket[_txexpr-element]s are strings. But it's unwise to pass
]
@deftogether[(
@defthing[deleted-signal symbol?]
@defproc[
(splitf-txexpr
[tx txexpr?]
[pred procedure?]
[replace-proc procedure? (λ (x) deleted-signal)])
[replace-proc procedure? (λ (x) #f)])
(values txexpr? (listof txexpr-element?))]
)]
Recursively descend through @racket[_txexpr] and extract all elements that match @racket[_pred]. Returns two values: a @racket[_txexpr] with the matching elements removed, and the list of matching elements. Sort of esoteric, but I've needed it more than once, so here it is.
@examples[#:eval my-eval
@ -489,7 +483,7 @@ Recursively descend through @racket[_txexpr] and extract all elements that match
(splitf-txexpr tx is-meta?)
]
Ordinarily, the result of the split operation is to remove the elements that match @racket[_pred]. This happens only when returning @racket[_deleted-signal]. You can change this behavior with the optional @racket[_replace-proc] argument.
Ordinarily, the result of the split operation is to remove the elements that match @racket[_pred]. But you can change this behavior with the optional @racket[_replace-proc] argument.
@examples[#:eval my-eval
(define tx '(div "Wonderful day" (meta "weather" "good") "for a walk"))

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