racket/collects/scheme/require.ss
Eli Barzilay 5a7ce88ac0 added filtered-in and -out
svn: r10826
2008-07-17 23:02:56 +00:00

66 lines
2.6 KiB
Scheme

#lang scheme/base
(require (for-syntax scheme/base scheme/require-transform scheme/list
"private/at-syntax.ss"))
(provide matching-identifiers-in)
(define-syntax matching-identifiers-in
(make-require-transformer
(lambda (stx)
(syntax-case stx ()
[(_ rx spec)
(regexp? (syntax-e #'rx))
(let ([rx (syntax-e #'rx)])
(define-values [imports sources] (expand-import #'spec))
(values (filter (lambda (i)
(regexp-match? rx (symbol->string
(syntax-e (import-local-id i)))))
imports)
sources))]))))
(provide subtract-in)
(define-syntax subtract-in
(make-require-transformer
(lambda (stx)
(syntax-case stx ()
[(_ spec specs ...)
(let* ([subs (map (lambda (spec)
(let-values ([(imports srcs) (expand-import spec)])
imports))
(syntax->list #'(specs ...)))]
[subs (map (lambda (i) (syntax-e (import-local-id i)))
(apply append subs))])
(define-values [imports sources] (expand-import #'spec))
(values (filter (lambda (i)
(not (memq (syntax-e (import-local-id i)) subs)))
imports)
sources))]))))
(provide filtered-in)
(define-syntax filtered-in
(make-require-transformer
(lambda (stx)
(syntax-case stx ()
[(_ proc spec)
(let ([proc (at-syntax #'proc)])
(define-values [imports sources] (expand-import #'spec))
(values
(filter-map
(lambda (i)
(let* ([id (import-local-id i)]
[s1 (symbol->string (syntax-e id))]
[s2 (proc s1)])
(cond [(equal? s1 s2) i]
[(string? s2) (make-import (datum->syntax
id (string->symbol s2) id)
(import-src-sym i)
(import-src-mod-path i)
(import-mode i)
(import-req-mode i)
(import-orig-mode i)
(import-orig-stx i))]
[(not s2) #f]
[else (error 'filtered-in "bad result: ~e" s2)])))
imports)
sources))]))))