Hello,
Using 'file-select' as a sub-second sleep procedure works without hitch under
csi:
(define (sleeper tm)
(let ((currms (current-milliseconds)))
(let-values (((_ __) (file-select #f #f tm)))
(print (- (current-milliseconds) currms)))))
;1> (sleeper 0.05)
50.0
However, compiling with csc produces several warnings:
Warning: in local procedure `find-err',
in local unknown procedure,
in toplevel unknown procedure:
(compose.scm:260) in procedure call to `file-select', expected argument #1 of
type `(list-of fixnum)', but was given an argument of type `boolean'
Warning: in local procedure `find-err',
in local unknown procedure,
in toplevel unknown procedure:
(compose.scm:260) in procedure call to `file-select', expected argument #2 of
type `(list-of fixnum)', but was given an argument of type `boolean'
Warning: in local procedure `find-err',
in local unknown procedure,
in toplevel unknown procedure:
(compose.scm:260) in procedure call to `file-select', expected argument #3 of
type `fixnum', but was given an argument of type `float'
In types.db, we have:
(file-select (#(procedure #:clean #:enforce) file-select ((list-of fixnum)
(list-of fixnum) #!optional fixnum) * *))
Based on the description of 'file-select' in the manual, and performance in
csi, it seeems it would be more accurate to declare:
(file-select (#(procedure #:clean #:enforce) file-select ((or boolean
(list-of fixnum)) (or boolean (list-of fixnum)) #!optional (or fixnum float)
(or boolean (list-of fixnum)) (or boolean (list-of fixnum)))))
Of course, having a "real" usleep function would be cleaner than faking it with
file-select, especially as implementing a usleep procedure is pretty trivial:
(define usleep (foreign-lambda int "usleep" unsigned-integer32))
Maybe it wouldn't be too much trouble to add it to the posix (or some other)
module.
Thanks,
J. Altfas
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