defer(3tcl) | Defered execution ala Go | defer(3tcl) |
defer - Defered execution
package require Tcl 8.6
package require defer ?1?
::defer::defer ?command? ?arg1? ?arg2? ?argN...?
::defer::with variableList script
::defer::autowith script
::defer::cancel ?id...?
The defer commands allow a developer to schedule actions to happen as part of the current variable scope terminating. This is most useful for dealing with cleanup activities. Since the defered actions always execute, and always execute in the reverse order from which the defer statements themselves execute, the programmer can schedule the cleanup of a resource (for example, a channel) as soon as that resource is acquired. Then, later if the procedure or lambda ends, either due to an error, or an explicit return, the cleanup of that resource will always occur.
package require defer 1 apply {{} { set fd [open /dev/null] defer::defer close $fd }}
Roy Keene
This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category defer 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.
cleanup, golang
Utility
Copyright (c) 2017, Roy Keene
1 | tcllib |