tcl::chan::halfpipe(3tcReflected/virtual channel supptcl::chan::halfpipe(3tcl)
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NAME
tcl::chan::halfpipe - In-memory channel, half of a fifo2
SYNOPSIS
package require Tcl 8.5
package require TclOO
package require tcl::chan::events ?1?
package require tcl::chan::halfpipe ?1.0.1?
::tcl::chan::halfpipe ?-option value...?
objectCmd put bytes
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DESCRIPTION
The tcl::chan::halfpipe package provides a command creating one half of
a tcl::chan::fifo2 pair. Writing into such a channel invokes a set of
callbacks which then handle the data. This is similar to a channel han-
dler, except having a much simpler API.
The internal TclOO class implementing the channel handler is a sub-
class of the tcl::chan::events framework.
API
::tcl::chan::halfpipe ?-option value...?
This command creates a halfpipe channel and configures it with
the callbacks to run when the channel is closed, data was writ-
ten to it, or ran empty. See the section Options for the list of
options and associated semantics. The result of the command is
a list containing two elements, the handle of the new channel,
and the object command of the channel handler, in this order.
The latter is supplied to the caller to provide her with access
to the put method for adding data to the channel.
Two halfpipes with a bit of glue logic in the callbacks make for
one tcl::chan::fifo2.
objectCmd put bytes
This method of the channel handler object puts the data bytes
into the channel so that it can be read from it.
OPTIONS
-close-command cmdprefix
This callback is invoked when the channel is closed. A single
argument is supplied, the handle of the channel being closed.
The result of the callback is ignored.
-write-command cmdprefix
This callback is invoked when data is written to the channel.
Two arguments are supplied, the handle of the channel written
to, and the data written. The result of the callback is ig-
nored.
-empty-command cmdprefix
This callback is invoked when the channel has run out of data to
read. A single argument is supplied, the handle of the channel.
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category virtchan-
nel 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
callbacks, fifo, in-memory channel, reflected channel, tip 219, virtual
channel
CATEGORY
Channels
COPYRIGHT
Copyright (c) 2009, 2019 Andreas Kupries <andreas_kupries@users.sourceforge.net>
tcllib 1.0.1 tcl::chan::halfpipe(3tcl)