23 lines
628 B
Scheme
23 lines
628 B
Scheme
#!r6rs
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;; SRFI-145 r6rs implemntation
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;;
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;; Copyright (C) Marc Nieper-Wißkirchen (2016). All Rights Reserved.
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;;
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;; Slight modifications by Andy Keep. This uses the SRFI-0 cond-expand and
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;; SRFI-23 error in place of the R7RS versions from the SRFI sample
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;; implementation.
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(library (srfi :145 assumptions)
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(export assume)
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(import (except (rnrs) error) (srfi :0) (srfi :23))
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(define-syntax assume
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(syntax-rules ()
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[(_ expression message ...)
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(cond-expand
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[debug
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(unless expression
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(error "invalid assumption" 'expression message ...))]
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[else (if #f #f)])])))
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