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Allegro CL version 8.2
Unrevised from 8.1 to 8.2.
8.1 version

add-stream-instance-flags

Arguments: stream &rest flag-names

This macro adds (via logior) instance flags to or zeroes instance flags out of the standard-instance object that is the stream. Note that this flags field has no correlation to a flags slot in the stream. You may inspect a stream in raw mode to see the instance-flags (see inspector.htm).

The behavior depends on the first of the flag-names arguments. If it is a keyword specifying a valid instance flag, then it and all the remaining keyword-named instance flags are added. But if the first of the flag-names arguments is a list of flag names, then those are zeroed out before the remaining flag-names (if any) are added. For example, the form

(add-stream-instance-flags stream (:gray :dual :string) :simple)

first ensures that the :gray, :dual, and :string bits are zero, before ensuring that the :simple bit is set. This is done without modifiying the :input or :output bits. On the other hand, this form

(add-stream-instance-flags stream :string :simple)

simply ensures the :string and :simple flags are set.

Valid instance flags are placed into the following groups:

You must load the :iodefs module to use this macro. Do that by evaluating (require :iodefs). (It is not an error to evaluate that form if the module is already loaded.) This macro is intended for implementing device-level functionality and should not be used except for that purpose. See Simple-stream Description in streams.htm for a description of the device-level.

See streams.htm for information on the simple-streams implementation in Allegro CL.


Copyright (c) 1998-2012, Franz Inc. Oakland, CA., USA. All rights reserved.
Documentation for Allegro CL version 8.2. This page was not revised from the 8.1 page.
Created 2010.1.21.

ToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 8.2
Unrevised from 8.1 to 8.2.
8.1 version