| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |
Arguments:
Although the basic algorithm of a Lisp listener is a simple repetition of
(print (eval (read)))
it is greatly complicated by the need to handle command history, error levels, and other useful features. When an application needs a Lisp listener, often it will be simplest to use this, the default Lisp listener provided by the Allegro CL top level. It takes no arguments, but must be run inside a start-interactive-top-level function. This function does not return. Listeners stop through a non-local exit (triggered, for example, by a call to exit).
The Allegro CL idiom for running a standard Lisp listener
communicating with *terminal-io*
(this might be done in a *restart-app-function*
) looks
something like this:
(tpl:start-interactive-top-level *terminal-io* #'tpl:top-level-read-eval-print-loop nil)
And the idiom for running a standard Lisp listener inside a window looks something like this:
(process-run-function "My Lisp Listener" #'tpl:start-interactive-top-level my-window-stream #'tpl:top-level-read-eval-print-loop nil)
Entry to top-level-read-eval-print-loop
establishes additional bindings for certain variables used by the top
level loop. These bindings are established inside any bindings
established by start-interactive-top-level. The
variables and initial binding values are taken from the alist bound to
the variable *default-lisp-listener-bindings*
.
An operator with this name but with a different definition is used in
a Lisp image built with a minimal top level, that is built with the
include-tpl argument to build-lisp-image specified nil
. See Minimal top levels in
building-images.htm for information on minimal top
levels. Follow the link to see the definition (Lisp source code) of
top-level-read-eval-print-loop in a
minimal top level.
See top-level.htm for more information on the top level.
Copyright (c) 1998-2016, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.1 page.
Created 2010.1.21.
| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |