Ubuntu Manpage: coroutine - Coroutine based event and IO handling

NAME

       coroutine - Coroutine based event and IO handling

SYNOPSIS

       package require Tcl  8.6

       package require coroutine  1.3

       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 puts ?-nonewline? channel string

       coroutine::util read -nonewline chan ?n?

       coroutine::util socket ?options...? host port

       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 puts ?-nonewline? channel string
This commands writes the string to the specified channel. Contrary to the builtin
puts this command waits until the channel is writable before actually writing to
it.

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 socket ?options...? host port
This command connects to the specified host and port and returns when that is done.
Contrary to the builtin command it performs a non-blocking connect in the
background. As such, while its blocks the calling coroutine, the overall
application is not blocked.

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

COPYRIGHT

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