NAME

       coroutine - Coroutine based event and IO handling

SYNOPSIS

       package require Tcl  8.6

       package require coroutine  1.2

       coroutine::util after delay

       coroutine::util await varname...

       coroutine::util create arg...

       coroutine::util exit ?status?

       coroutine::util gets chan ?varname?

       coroutine::util gets_safety chan limit varname

       coroutine::util global varname...

       coroutine::util read -nonewline chan ?n?

       coroutine::util update ?idletasks?

       coroutine::util vwait varname

_________________________________________________________________________________________________

DESCRIPTION

       The  coroutine  package  provides  coroutine-aware  implementations  of various event- and
       channel related commands. It can be in multiple modes:

       [1]    Call the commands through their ensemble, in code which is explicitly  written  for
              use within coroutines.

       [2]    Import  the  commands into a namespace, either directly, or through namespace path.
              This allows the use from within code  which  is  not  coroutine-aware  per  se  and
              restricted to specific namespaces.

       A  more  agressive form of making code coroutine-oblivious than point 2 above is available
       through the package coroutine::auto, which intercepts the relevant  builtin  commands  and
       changes  their implementation dependending on the context they are run in, i.e.  inside or
       outside of a coroutine.

API

       All the commands listed below are synchronous with respect to the coroutine invoking them,
       i.e.  this  coroutine  blocks  until the result is available. The overall eventloop is not
       blocked however.

       coroutine::util after delay
              This command delays the coroutine invoking it by delay milliseconds.

       coroutine::util await varname...
              This command is an extension form of the coroutine::util vwait command (see  below)
              which waits on a write to one of many named namespace variables.

       coroutine::util create arg...
              This command creates a new coroutine with an automatically assigned name and causes
              it to run the code specified by the arguments.

       coroutine::util exit ?status?
              This command exits the current coroutine, causing it to return status. If no status
              was specified the default 0 is returned.

       coroutine::util gets chan ?varname?
              This  command  reads  a  line  from  the  channel chan and returns it either as its
              result, or, if a varname was specified, writes it to the named variable and returns
              the number of characters read.

       coroutine::util gets_safety chan limit varname
              This  command  reads  a  line from the channel chan up to size limit and stores the
              result in varname. Of limit is reached before the set first newline,  an  error  is
              thrown. The command returns the number of characters read.

       coroutine::util global varname...
              This  command  imports the named global variables of the coroutine into the current
              scope. From the technical point of view these variables reside in level #1  of  the
              Tcl  stack.  I.e.  these  are  not  the  regular  global  variable in to the global
              namespace, and each coroutine can have their own set, independent of all others.

       coroutine::util read -nonewline chan ?n?
              This command reads n characters from the channel  chan  and  returns  them  as  its
              result.  If  n  is  not  specified  the  command will read the channel until EOF is
              reached.

       coroutine::util update ?idletasks?
              This command causes the coroutine  invoking  it  to  run  pending  events  or  idle
              handlers before proceeding.

       coroutine::util vwait varname
              This  command  causes  the  coroutine  calling  it to wait for a write to the named
              namespace variable varname.

BUGS, IDEAS, FEEDBACK

       This document, and the package it describes,  will  undoubtedly  contain  bugs  and  other
       problems.    Please  report  such  in  the  category  coroutine  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 output 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

       after,  channel,  coroutine,  events,  exit,  gets,  global, green threads, read, threads,
       update, vwait

CATEGORY

       Coroutine

COPYRIGHT

       Copyright (c) 2010-2015 Andreas Kupries <andreas_kupries@users.sourceforge.net>