chibi-scheme/lib/srfi/145.sld
2020-08-29 11:11:46 +02:00

23 lines
689 B
Scheme

(define-library (srfi 145)
(export assume)
(import (scheme base))
(cond-expand
((or elide-assumptions
(and (not assumptions)
(not debug)))
(begin
(define-syntax assume
(syntax-rules ()
((assume expression objs ...)
expression)
((assume)
(syntax-error "assume requires an expression"))))))
(else
(begin
(define-syntax assume
(syntax-rules ()
((assume expression objs ...)
(or expression
(error "invalid assumption" 'expression objs ...)))
((assume)
(syntax-error "assume requires an expression"))))))))