NAME¶
oo::util - Utility commands for TclOO
SYNOPSIS¶
package require
Tcl 8.5
package require
TclOO
package require
oo::util ?1.1?
mymethod method ?
arg...?
classmethod name arguments body
classvariable ?
arg...?
link method...
link {
alias method}...
ooutil::singleton ?
arg...?
DESCRIPTION¶
This package provides a convenience command for the easy specification of
instance methods as callback commands, like timers, file events, Tk bindings,
etc.
COMMANDS¶
- mymethod method ?arg...?
- This command is available within instance methods. It takes a method name
and, possibly, arguments for the method and returns a command prefix
which, when executed, will invoke the named method of the object we are
in, with the provided arguments, and any others supplied at the time of
actual invokation.
Note: The command is equivalent to and named after the command provided by
the OO package snit for the same purpose.
- classmethod name arguments body
- This command is available within class definitions. It takes a method name
and, possibly, arguments for the method and creates a method on the class,
available to a user of the class and of derived classes.
Note: The command is equivalent to the command typemethod provided by
the OO package snit for the same purpose.
Example
oo::class create ActiveRecord {
classmethod find args { puts "[self] called with arguments: $args" }
}
oo::class create Table {
superclass ActiveRecord
}
puts [Table find foo bar]
# ======
# which will write
# ======
# ::Table called with arguments: foo bar
- classvariable ?arg...?
- This command is available within instance methods. It takes a series of
variable names and makes them available in the method's scope. The
originating scope for the variables is the class (instance) the object
instance belongs to. In other words, the referenced variables are shared
between all instances of their class.
Note: The command is roughly equivalent to the command typevariable
provided by the OO package snit for the same purpose. The
difference is that it cannot be used in the class definition itself.
Example:
% oo::class create Foo {
method bar {z} {
classvariable x y
return [incr x $z],[incr y]
}
}
::Foo
% Foo create a
::a
% Foo create b
::b
% a bar 2
2,1
% a bar 3
5,2
% b bar 7
12,3
% b bar -1
11,4
% a bar 0
11,5
- link method...
- link {alias method}...
- This command is available within instance methods. It takes a list of
method names and/or pairs of alias- and method-name and makes the named
methods available to all instance methods without requiring the my
command.
The alias name under which the method becomes available defaults to the
method name, except where explicitly specified through an alias/method
pair.
Examples:
link foo
# The method foo is now directly accessible as foo instead of my foo.
link {bar foo}
# The method foo is now directly accessible as bar.
link a b c
# The methods a, b, and c all become directly acessible under their
# own names.
- The main use of this command is expected to be in instance constructors,
for convenience, or to set up some methods for use in a mini DSL.
- ooutil::singleton ?arg...?
- This command is a meta-class, i.e. a variant of the builtin
oo::class which ensures that it creates only a single instance of
the classes defined with it.
Syntax and results are like for oo::class.
Example:
% oo::class create example {
self mixin singleton
method foo {} {self}
}
::example
% [example new] foo
::oo::Obj22
% [example new] foo
::oo::Obj22
AUTHORS¶
Donal Fellows, Andreas Kupries
BUGS, IDEAS, FEEDBACK¶
This document, and the package it describes, will undoubtedly contain bugs and
other problems. Please report such in the category
oo::util 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.
SEE ALSO¶
snit(3tcl)
KEYWORDS¶
TclOO, callback, class methods, class variables, command prefix, currying,
method reference, my method, singleton
CATEGORY¶
Utility
COPYRIGHT¶
Copyright (c) 2011-2013 Andreas Kupries, BSD licensed