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?
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19       package require tcl::chan::halfpipe  ?1?
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21       ::tcl::chan::halfpipe ?-option value...?
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23       objectCmd put bytes
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DESCRIPTION

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

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

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

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

86       callbacks, fifo, in-memory channel, reflected channel, tip 219, virtual
87       channel
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CATEGORY

90       Channels
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93       Copyright (c) 2009 Andreas Kupries <andreas_kupries@users.sourceforge.net>
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98tcllib                                 1                tcl::chan::halfpipe(n)
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