[r6rs-discuss] Question on buffer modes

From: R. Kent Dybvig <dyb>
Date: Wed, 23 May 2007 22:20:59 -0400

> In section "8.3.2. Buffer modes", the second and
> third paragraphs talk about ports that are connected
> to the same mutable source, yet I'm not seeing how
> one would actually get two ports to connect to the
> same source to begin with. Am I overlooking where
> that mechanism is described in the report?

In most implementations, the ports returned by multiple calls to
standard-input-port will be connected to the same source. Similarly, the
ports returned by multiple calls to standard-output-port or
standard-error-port may be connected to the same sink; in fact, a port
returned by standard-output-port may be connected to the same sink as a
port returned by standard-error-port. The current-output and
current-error ports may be connected to the same sink at the time the
program starts. One can also get two ports to connect to the same source
or sink via custom ports. For example, you might create two custom ports
that forward data from the same file, string, or bytevector port.

Kent
Received on Wed May 23 2007 - 22:20:59 UTC