> On May 16, 2018, at 6:37 AM, Jens Axel Søgaard <jensa...@soegaard.net> wrote:
>
> Alternative 1: Use filtered-in to require renamed versions.
>
> ( <>filtered-in
> <http://docs.racket-lang.org/reference/require.html?q=regexp-in#%28form._%28%28lib._racket%2Frequire..rkt%29._filtered-in%29%29>
> proc-expr require-spec)
> Applies an arbitrary transformation on the import names (as strings) of
> require-spec. The proc-expr must evaluate at expansion time to a
> single-argument procedure, which is applied on each of the names from
> require-spec. For each name, the procedure must return either a string for
> the import’s new name or #f to exclude the import.
>
>
> For example,
> (require
> <http://docs.racket-lang.org/reference/require.html?q=regexp-in#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._require%29%29>
> (filtered-in
> <http://docs.racket-lang.org/reference/require.html?q=regexp-in#%28form._%28%28lib._racket%2Frequire..rkt%29._filtered-in%29%29>
> (lambda
> <http://docs.racket-lang.org/reference/lambda.html?q=regexp-in#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._lambda%29%29>
> (name)
> (and
> <http://docs.racket-lang.org/reference/if.html?q=regexp-in#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._and%29%29>
> (regexp-match?
> <http://docs.racket-lang.org/reference/regexp.html?q=regexp-in#%28def._%28%28quote._~23~25kernel%29._regexp-match~3f%29%29>
> #rx"^[a-z-]+$" name)
> (regexp-replace
> <http://docs.racket-lang.org/reference/regexp.html?q=regexp-in#%28def._%28%28quote._~23~25kernel%29._regexp-replace%29%29>
> #rx"-" (string-titlecase
> <http://docs.racket-lang.org/reference/strings.html?q=regexp-in#%28def._%28%28quote._~23~25kernel%29._string-titlecase%29%29>
> name) "")))
> racket/base))
> imports only bindings from racket/base
> <http://docs.racket-lang.org/reference/index.html?q=regexp-in> that match the
> pattern #rx"^[a-z-]+$", and it converts the names to “camel case.”
> Alternative 1 is best.
>
> /Jens Axel
Here is a `transform-right-arrow-in` definition that transforms -> into →:
#lang racket
(require racket/require
racket/require-syntax
(for-syntax syntax/parse))
(begin-for-syntax
;; String -> String
(define (transform-right-arrow name)
(regexp-replace* #rx"->" name "→")))
(define-require-syntax transform-right-arrow-in
(syntax-parser
[(transform-right-arrow-in require-spec)
#'(filtered-in transform-right-arrow require-spec)]))
;; Using it:
(require (transform-right-arrow-in racket/base))
(symbol→string 'blubber)
(string→number "987")
(real→double-flonum 377)
(list→vector (list 144 233 377 610 987 1597))
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