1tcl::chan::halfpipe(n) Reflected/virtual channel supporttcl::chan::halfpipe(n)
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NAME

8       tcl::chan::halfpipe - In-memory channel, half of a fifo2
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SYNOPSIS

11       package require Tcl  8.5
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13       package require TclOO
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15       package require tcl::chan::events  ?1?
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17       package require tcl::chan::halfpipe  ?1.0.1?
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19       ::tcl::chan::halfpipe ?-option value...?
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21       objectCmd put bytes
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DESCRIPTION

26       The tcl::chan::halfpipe package provides a command creating one half of
27       a tcl::chan::fifo2 pair. Writing into such a channel invokes a  set  of
28       callbacks which then handle the data. This is similar to a channel han‐
29       dler, except having a much simpler API.
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31       The internal TclOO class implementing the channel  handler  is  a  sub-
32       class of the tcl::chan::events framework.
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API

35       ::tcl::chan::halfpipe ?-option value...?
36              This  command  creates a halfpipe channel and configures it with
37              the callbacks to run when the channel is closed, data was  writ‐
38              ten to it, or ran empty. See the section Options for the list of
39              options and associated semantics.  The result of the command  is
40              a  list  containing two elements, the handle of the new channel,
41              and the object command of the channel handler,  in  this  order.
42              The  latter is supplied to the caller to provide her with access
43              to the put method for adding data to the channel.
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45              Two halfpipes with a bit of glue logic in the callbacks make for
46              one tcl::chan::fifo2.
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48       objectCmd put bytes
49              This  method  of  the channel handler object puts the data bytes
50              into the channel so that it can be read from it.
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OPTIONS

53       -close-command cmdprefix
54              This callback is invoked when the channel is closed.   A  single
55              argument  is  supplied,  the handle of the channel being closed.
56              The result of the callback is ignored.
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58       -write-command cmdprefix
59              This callback is invoked when data is written  to  the  channel.
60              Two  arguments  are  supplied, the handle of the channel written
61              to, and the data written.  The result of  the  callback  is  ig‐
62              nored.
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64       -empty-command cmdprefix
65              This callback is invoked when the channel has run out of data to
66              read.  A single argument is supplied, the handle of the channel.
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BUGS, IDEAS, FEEDBACK

69       This document, and the package it describes, will  undoubtedly  contain
70       bugs  and other problems.  Please report such in the category virtchan‐
71       nel  of  the  Tcllib  Trackers  [http://core.tcl.tk/tcllib/reportlist].
72       Please  also  report any ideas for enhancements you may have for either
73       package and/or documentation.
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75       When proposing code changes, please provide unified diffs, i.e the out‐
76       put of diff -u.
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78       Note  further  that  attachments  are  strongly  preferred over inlined
79       patches. Attachments can be made by going  to  the  Edit  form  of  the
80       ticket  immediately  after  its  creation, and then using the left-most
81       button in the secondary navigation bar.
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KEYWORDS

84       callbacks, fifo, in-memory channel, reflected channel, tip 219, virtual
85       channel
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CATEGORY

88       Channels
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91       Copyright (c) 2009, 2019 Andreas Kupries <andreas_kupries@users.sourceforge.net>
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96tcllib                               1.0.1              tcl::chan::halfpipe(n)
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