31 lines
1.0 KiB
Scheme
31 lines
1.0 KiB
Scheme
#lang scheme/base
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(require (for-syntax scheme/base scheme/provide-transform))
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(provide matching-identifiers-out)
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(define-syntax matching-identifiers-out
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(make-provide-transformer
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(lambda (stx modes)
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(syntax-case stx ()
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[(_ rx spec)
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(regexp? (syntax-e #'rx))
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(let ([rx (syntax-e #'rx)])
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(filter (lambda (e)
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(regexp-match? rx (symbol->string (export-out-sym e))))
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(expand-export #'spec modes)))]))))
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#| Cute, and symmetric to subtract-in, but useless
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(provide subtract-out)
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(define-syntax subtract-out
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(make-provide-transformer
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(lambda (stx modes)
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(syntax-case stx ()
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[(_ spec specs ...)
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(let* ([subs (map (lambda (spec) (expand-export spec modes))
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(syntax->list #'(specs ...)))]
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[subs (map (lambda (i) (syntax-e (export-out-sym i)))
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(apply append subs))])
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(filter (lambda (i) (not (memq (export-out-sym i) subs)))
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(expand-export #'spec modes)))]))))
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|#
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