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

38 lines
1.4 KiB
Scheme

#lang scheme/base
(require (for-syntax scheme/base scheme/provide-transform scheme/list
"private/at-syntax.ss"))
(provide matching-identifiers-out)
(define-syntax matching-identifiers-out
(make-provide-transformer
(lambda (stx modes)
(syntax-case stx ()
[(_ rx spec)
(regexp? (syntax-e #'rx))
(let ([rx (syntax-e #'rx)])
(filter (lambda (e)
(regexp-match? rx (symbol->string (export-out-sym e))))
(expand-export #'spec modes)))]))))
(provide filtered-out)
(define-syntax filtered-out
(make-provide-transformer
(lambda (stx modes)
(syntax-case stx ()
[(_ proc spec)
(let ([proc (at-syntax #'proc)])
(filter-map
(lambda (e)
(let* ([s1 (symbol->string (export-out-sym e))]
[s2 (proc s1)])
(cond [(equal? s1 s2) e]
[(string? s2) (make-export (export-local-id e)
(string->symbol s2)
(export-mode e)
(export-protect? e)
(export-orig-stx e))]
[(not s2) #f]
[else (error 'filtered-out "bad result: ~e" s2)])))
(expand-export #'spec modes)))]))))