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#lang scribble/manual
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@(require scribble/eval (for-label racket sugar))
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@(define my-eval (make-base-eval))
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@(my-eval `(require sugar))
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@title{List}
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@defmodule[sugar/list]
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@defproc[
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(trimf
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[lst list?]
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[pred procedure?])
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list?]
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Drop elements from each end of @racket[_lst] that satisfy @racket[_pred]. Exactly equivalent to @racket[(dropf-right (dropf _lst _pred) _pred)].
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@examples[#:eval my-eval
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(trimf '(1 2 3 a b c 4 5 6) integer?)
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(trimf '(1 2 3 a b c) integer?)
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(trimf '(a b c) integer?)
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(trimf '(a b c 1 2 3 d e f) integer?)]
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@defproc[
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(filter-split
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[lst list?]
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[pred procedure?])
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(listof list?)]
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Like @racket[string-split], but for lists. Drop elements from anywhere in @racket[_lst] that satisfy @racket[_pred] — ends, middle, you name it — and return a list of the sublists that remain.
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@examples[#:eval my-eval
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(filter-split '(1 a b c 2 d e f 3) integer?)
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(filter-split '(1 a b c 2 d e f 3) (compose not integer?))
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(filter-split '(a b c 1 2 3 d e f) integer?)
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(filter-split '(a b c 1 2 3 d e f) (compose not integer?))]
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@defproc[
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(frequency-hash
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[lst list?])
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hash?]
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Count the frequency of each element in @racket[_lst], and return a hash whose keys are the unique elements of @racket[_lst], and each value is the frequency of that element within @racket[_lst].
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@examples[#:eval my-eval
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(frequency-hash '(a b b c c c))
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(frequency-hash '(c b c a b c))
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]
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@defproc[
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(members-unique?
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[container (or/c list? vector? string?)])
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boolean?]
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Return @racket[#t] if every element in @racket[_container] is unique, otherwise @racket[#f].
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@examples[#:eval my-eval
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(members-unique? '(a b c d e f))
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(members-unique? '(a b c d e f a))
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]
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@defproc[
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(members-unique?/error
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[container (or/c list? vector? string?)])
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boolean?]
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Same as @racket[members-unique?], but if the members are not unique, raises a descriptive error rather than returning @racket[#f].
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@examples[#:eval my-eval
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(members-unique?/error '(a b c d e f))
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(members-unique?/error '(a b c d e f a))
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(members-unique?/error '(a b c d e f a b))
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]
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