52 lines
1.5 KiB
Racket
52 lines
1.5 KiB
Racket
#lang scribble/manual
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@(require scribble/eval
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(for-label unstable/struct
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scheme/contract
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scheme/base))
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@title[#:tag "struct"]{Structs}
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@(define the-eval (make-base-eval))
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@(the-eval '(require unstable/struct))
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@defmodule[unstable/struct]
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@defform[(make struct-id expr ...)]{
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Creates an instance of @scheme[struct-id], which must be bound as a
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struct name. The number of @scheme[expr]s is statically checked
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against the number of fields associated with @scheme[struct-id]. If
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they are different, or if the number of fields is not known, an error
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is raised at compile time.
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@examples[#:eval the-eval
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(define-struct triple (a b c))
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(make triple 3 4 5)
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(make triple 2 4)
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]
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}
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@defproc[(struct->list [v any/c]
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[#:false-on-opaque? false-on-opaque? boolean? #f])
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(or/c list? #f)]{
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Returns a list containing the struct instance @scheme[v]'s
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fields. Unlike @scheme[struct->vector], the struct name itself is not
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included.
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The struct instance @scheme[v] must be fully accessible using the
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current inspector. If any fields are inaccessible, either an error is
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raised or @scheme[#f] is returned, depending on the value of
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@scheme[false-on-opaque?]. The default is to raise an error.
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@examples[#:eval the-eval
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(define-struct open (u v) #:transparent)
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(struct->list (make-open 'a 'b))
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(struct->list #s(pre 1 2 3))
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(define-struct secret (x y))
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(struct->list (make-secret 17 22))
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(struct->list (make-secret 17 22) #:false-on-opaque? #t)
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(struct->list 'not-a-struct #:false-on-opaque? #t)
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]
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}
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