From: mwh@gradin.cis.upenn.edu (Michael Hicks)
Newsgroups: comp.lang.scheme.scsh
Date: 4 Apr 1996 22:38:42 GMT
I am having trouble getting the | process form to work. I looked in the
source and it indicates that some schemes don't allow inputting |, and to
use pipe or pipe+ if this is a problem.
True, but irrelevant. The scsh implementation I built reads the "|" character
with no trouble.
I've tried these as well and I
get the same problem (unrecognized identifier | or pipe+, etc.). It does
recognize a pipe function, but that doesn't seem to work.
The important point to realize is that the pipe process form is *not*
a Scheme expression. It is a process form expression. You can put it
in a Scheme program by embedding it within a RUN, EXEC-EPF, or & form.
This is a process form:
(| (ls) (lpr))
These are Scheme expressions:
(run (| (ls) (lpr)))
(& (| (ls) (lpr)))
Does that help?
-Olin
|