28 lines
576 B
Scheme
28 lines
576 B
Scheme
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(module util mzscheme
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(provide extract-until)
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(require (lib "stx.ss" "syntax"))
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(define extract-until
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(case-lambda
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[(r ids keep?)
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(let loop ([r r][val-stxs null])
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(cond
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[(stx-null? r)
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(values #f #f #f)]
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[(and (identifier? (stx-car r))
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(ormap (lambda (id)
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(module-identifier=? id (stx-car r)))
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ids))
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(values (reverse (if keep?
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(cons (stx-car r) val-stxs)
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val-stxs))
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r
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(stx-car r))]
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[else
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(loop (stx-cdr r) (cons (stx-car r) val-stxs))]))]
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[(r ids) (extract-until r ids #f)])))
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