55 lines
1.7 KiB
Racket
55 lines
1.7 KiB
Racket
#lang scribble/doc
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@(require "common.ss"
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"match-grammar.ss"
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(for-label mzlib/match))
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@(begin
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(define-syntax-rule (bind id)
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(begin
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(require scheme/match)
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(define id (scheme match))))
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(bind scheme-match))
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@mzlib[#:mode title match]
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The @schememodname[mzlib/match] library provides a @scheme[match] form
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similar to that of @schememodname[scheme/match], but with an different
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(older and less extensible) syntax of patterns.
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@defform/subs[(match val-expr clause ...)
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([clause [pat expr ...+]
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[pat (=> id) expr ...+]])]{
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See @scheme-match from @schememodname[scheme/match] for a description
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of matching. The grammar of @scheme[pat] for this @scheme[match] is as
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follows:
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@|match-grammar|}
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@; ------------------------------------------------------------
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@deftogether[(
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@defform[(match-lambda clause ...)]
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@defform[(match-lambda* clause ...)]
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@defform[(match-let ([pat expr] ...) body ...+)]
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@defform[(match-let* ([pat expr] ...) body ...+)]
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@defform[(match-letrec ([pat expr] ...) body ...+)]
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@defform[(match-define pat expr)]
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)]{
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Analogous to the combined forms from @scheme[scheme/match].}
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@; ------------------------------------------------------------
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@deftogether[(
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@defform*[((define-match-expander id proc-expr)
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(define-match-expander id proc-expr proc-expr)
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(define-match-expander id proc-expr proc-expr proc-expr))]
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@defparam[match-equality-test comp-proc (any/c any/c . -> . any)]
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)]{
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Analogous to the form and parameter from @scheme[scheme/match]. The
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@scheme[define-match-expander] form, however, supports an extra
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@scheme[proc-expr] as the middle one: an expander for use with
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@scheme[match] from @schememodname[mzlib/match].}
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