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Re: A few random I/O proposals
On Wed, 27 May 92 15:58:01 EDT, "Andrew Wilcox" <firstname.lastname@example.org> said:
> I would suggest adapting the idea of an output procedure used in Marc
> Feeley's genwrite.scm from SLIB to make a more general make-output-
> port procedure:
> (make-output-port OUTPUT)
> make-output-port returns an output port. When an object is
> written to the output port, OUTPUT is called one or more times
> with one string argument, the successive substrings of the
> textual transformation of the object. OUTPUT may return #f to
> stop the transformation.
> This way you can write open-output-string, open-truncated-output-
> string, or other procedures you want.
I don't really understand this. Output ports should accept
characters, not arbitrary objects. And they shouldn't really be able
to stop anything. But I like the idea of being able to create a port
from a function - how about
(make-output-port WRITE-PROC CLOSE-PROC)
WRITE-PROC must be a procedure which takes a single argument, and
CLOSE-PROC must be a procedure which takes no arguments.
Make-output-port returns an output port. When a character is written
to the output port, WRITE-PROC is called with that character as its
argument. When the output port is closed, CLOSE-PROC is called with
Of course, there would also be a make-input-port, with WRITE-PROC
replaced by a READ-PROC of no arguments.
who also thinks that ports should be disjoint from other types