term::receive::bind(3tcl) Terminal control term::receive::bind(3tcl)
______________________________________________________________________________
NAME
term::receive::bind - Keyboard dispatch from terminals
SYNOPSIS
package require Tcl 8.4
package require term::receive::bind ?0.1?
term::receive::bind object ?map?
object map str cmd
object default cmd
object listen ?chan?
object unlisten ?chan?
object reset
object next char
object process str
object eof
______________________________________________________________________________
DESCRIPTION
This package provides a class for the creation of simple dispatchers
from character sequences to actions. Internally each dispatcher is in
essence a deterministic finite automaton with tree structure.
CLASS API
The package exports a single command, the class command, enabling the
creation of dispatcher instances. Its API is:
term::receive::bind object ?map?
This command creates a new dispatcher object with the name ob-
ject, initializes it, and returns the fully qualified name of
the object command as its result.
The argument is a dictionary mapping from strings, i.e. charac-
ter sequences to the command prefices to invoke when the se-
quence is found in the input stream.
OBJECT API
The objects created by the class command provide the methods listed be-
low:
object map str cmd
This method adds an additional mapping from the string str to
the action cmd. The mapping will take effect immediately should
the processor be in a prefix of str, or at the next reset opera-
tion. The action is a command prefix and will be invoked with
one argument appended to it, the character sequence causing the
invokation. It is executed in the global namespace.
object default cmd
This method defines a default action cmd which will be invoked
whenever an unknown character sequence is encountered. The com-
mand prefix is handled in the same as the regular action defined
via method map.
object listen ?chan?
This methods sets up a filevent listener for the channel with
handle chan and invokes the dispatcher object whenever charac-
ters have been received, or EOF was reached.
If not specified chan defaults to stdin.
object unlisten ?chan?
This methods removes the filevent listener for the channel with
handle chan.
If not specified chan defaults to stdin.
object reset
This method resets the character processor to the beginning of
the tree.
object next char
This method causes the character processor to process the char-
acter c. This may simply advance the internal state, or invoke
an associated action for a recognized sequence.
object process str
This method causes the character processor to process the char-
acter sequence str, advancing the internal state and invoking
action as necessary. This is a callback for listen.
object eof
This method causes the character processor to handle EOF on the
input. This is currently no-op. This is a callback for listen.
NOTES
The simplicity of the DFA means that it is not possible to recognize a
character sequence with has a another recognized character sequence as
its prefix.
In other words, the set of recognized strings has to form a prefix
code.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category term of
the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist]. Please
also report any ideas for enhancements you may have for either package
and/or documentation.
When proposing code changes, please provide unified diffs, i.e the out-
put of diff -u.
Note further that attachments are strongly preferred over inlined
patches. Attachments can be made by going to the Edit form of the
ticket immediately after its creation, and then using the left-most
button in the secondary navigation bar.
KEYWORDS
character input, control, dispatcher, listener, receiver, terminal
CATEGORY
Terminal control
COPYRIGHT
Copyright (c) 2006 Andreas Kupries <andreas_kupries@users.sourceforge.net>
tcllib 0.1 term::receive::bind(3tcl)