TclOO. Okay, got it.
I'm not much for extraneous syntax, but if you have to have it, ::oo:: is not a bad way to go. Looks cool. Pew pew pew, it's a spaceship. Or a spider. Maybe it's a moose. Maybe it's looking deeply into the eyes of a lover. ::oo:: is pretty cool, as far as syntax goes.
Well, it's been a long stretch in the JavaScript mines, better brush up on my canon.
TO THE WIKI! ALOHA!!
Commands ::oo::class new in 8.6 ::oo::copy new in 8.6 ::oo::define new in 8.6 ::oo::objdefine ::oo::object info info class provides introspection of classes (many subcommands) info object provides introspection of objects (many subcommands) Method Commands The following commands are only available within the body of a method my new in 8.6 next new in 8.6 self new in 8.6
Now, I'm not one of them big city software architects, but I can't help but notice there are some top level tcl commands, and all I know about them right now is that they are brand-spanking new, and they are only available within the body of a method. This feels, subtly, ever so slightly, on the fringes of my spider-sense, like name space pollution. Like, if ever there was a reason to use namespaces, wouldn't it be to prevent commands that can only be used in a specific context from becoming top level commands? I'm just thinking out loud here. We'll see later if perhaps some radical language modification or maybe a complex, streaming build system might come to our rescue on that.
Okay, folks, shows over. That's TclOO, you've seen it, time to get codi..
Wait- I think I've seen that spaceship-spider-moose lover before. Was her name Valerie? No, that's not it...
noop Sherlock/Mr. Robot-style eidetic memory sequence ensues, consisting mostly of tcl code, sandworms, and Stevie Nicks
Wait, I know! It was in the Tcllib 1.18 documentation! Yeah, it was ::oo::util, and of course, its twin, the other ::oo::util! I knew I saw it before. Wait, not just there, but.. somewhere..
noop Fragments from Madonna's 1984 video "Borderline" flash in rapid succession
No, it wasn't in the Tcllib 1.18 documentation, it was in the "README of Changes" of Tcllib 1.18! Of course it was, it was there the whole time, and we learned the true TclOO was the friendships we made along the way.
oodialect oo::dialect 0.3
oometa oo::meta 0.4.1
oo::option 0.3No, I'm wrong. Nothing here but a third of an infinite language, less than half of a meta infinity, and a ukulele option.
Hold on just a gosh darn minute! That's not even a tiny bit of a meta infinity, let alone almost half of one. It's that silly tcl namespacing, isn't it?
::::::::::::::::::::::::::::::::::info tclversion ::info tclversion info tclversion
Never judge a namespace by the number of preceding colons. That's what pappy used ta always say.
So herm, maybe that's all of them? Maybe it would do for now. So now what are we looking at again?
Commands ::oo::class new in 8.6 ::oo::copy new in 8.6 ::oo::define new in 8.6 ::oo::objdefine new in France ::oo::object big in Japan ::oo::util namespaces solve problems ::oo::util twice as nice as the last ::oo::util ::oo::dialect new in tcllib 1.18 release notes ::oo::meta new in tcllib 1.18 release notes ::oo::option new in tcllib 1.18 release notes ::info ::info class provides introspection of classes (many subcommands) ::info object provides introspection of objects (many subcommands) Method Commands The following commands are only available within the body of a method ::my new in 8.6 ::next new in 8.6 ::self to thine be true
Here's something from the wiki that you don't see every day
package require TclOO namespace import oo::*
hmmmmm.. I say let's give it the old college try
namespace import oo::*
So now class, object, copy, define, objdefine, info, my, next, & self boldly venture together into the global namespace. Now I can immediately see the upside of the ::oo:: namespace. "copy" and "define" don't especially scream to one's intuition, "I'm here to orient objectation!"
Lets try a OO finger exercise:
namespace import oo::* class create AClass set instance1 [AClass new] AClass create instance2 #instance1 destroy error! instance2 destroy AClass destroy class destroy
Okay, that's a little weird. Not sure why instance2 can be destroyed, and instance1 isn't as happy to do so. TO THE DOCS!
https://www.tcl.tk/man/tcl/TclCmd/class.htm
cls new ?arg ...? Note that this method is not exported by the oo::class object itself, so classes should not be created using this method.
Ah! So, don't do that. It's available, but clearly it has issues, and we have been warned. [class create] & [cls create] it is. Learning is power!
comment 2018-01-16: the reason set instance1 [AClass new] ; instance1 destroy doesn't work is that it is trying to destroy an object called instance1. instance1 is the name of a variable which contains an object name. Try set instance1 [AClass new] ; $instance1 destroy instead.
Thank you, stranger! You are indeed correct. Mea culpa.
namespace import oo::* class create AClass set instance1 [AClass new] AClass create instance2 $instance1 destroy ;# look ma, no errors! instance2 destroy AClass destroy class destroy
Also, I haven't figured out how to recover from [class destroy]. If you are following along at home, you probably want to fire up a new interpreter.
An 00 classic:
namespace import oo::*
class create Counter {
constructor {{num 0}} {
variable count
set count $num
}
method increment {{num 1}} {
variable count
incr count $num
}
method decrement {{num 1}} {
variable count
incr count -$num
}
method currentcount {} {
variable count
return $count
}
destructor {}
}
Counter create counter
puts [counter currentcount]
counter increment
counter increment 5
puts [counter currentcount]
counter decrement
counter decrement 3
puts [counter currentcount]Having originally discovered Tcl when downloading Ruby to play with some Pragmatic Programmers stuff back when dinosaurs yet roamed the earth, the word DRY springs to mind. I wonder if we can refactor this a bit, and get rid of some of those annoying [variable] commands.
We can! By shifting the [variable] command out of the constructor, and into the class definition, we can simplify our code.
namespace import oo::*
class create Counter {
variable count
constructor {{num 0}} {
set count $num
}
method increment {{num 1}} {
incr count $num
}
method decrement {{num 1}} {
incr count -$num
}
method currentcount {} {
return $count
}
destructor {}
}Sweet! But wait? methods? constructors? variables? I don't remember reading about any of that stuff in the [::oo::class] man page. I wonder if it just uses magic and pulls these out of the anonymous global array ::() somehow. Hmm, now that you mention it, I seem to recall..
noop Montage of Benedict Cumberbatch as Dr. Strange, interspersed with the male background dancers from Madonna's 1990 video "Vogue."
Okay, I don't even want to know what that was about.
The constructor of the oo::class class takes an optional argument which, if present, is sent to the oo::define command (along with the name of the newly-created class) to allow the class to be conveniently configured at creation time.
Ah! The top class of the hierarchy is mostly just a hollow shell, s̶o̶m̶e̶w̶h̶a̶t̶ ̶b̶r̶o̶k̶e̶n̶ ̶i̶n̶ ̶i̶t̶s̶e̶l̶f̶, benefiting from the efforts of others. Go fig.
CONFIGURING CLASSES
'oo::define class defScript
'oo::define class subcommand arg ?arg ...?
constructor argList bodyScript
deletemethod name ?name ...
destructor bodyScript
export name ?name ...?
filter ?-slotOperation? ?methodName ...?
forward name cmdName ?arg ...?
method name argList bodyScript
mixin ?-slotOperation? ?className ...?
renamemethod fromName toName
self subcommand arg ...
self script
superclass ?-slotOperation? ?className ...?
unexport name ?name ...?
variable ?-slotOperation? ?name ...?
Rise, [define]! Unshackle yourself from the imperialist ruling [class]. YOU CONTROL THE MEANS OF PRODUCTION! Viva la revolución!
namespace import oo::*
class create Counter
define Counter variable count
define Counter constructor {{num 0}} { set count $num }
define Counter method increment {{num 1}} { incr count $num }
define Counter method decrement {{num 1}} { incr count -$num }
define Counter method currentcount {} { return $count }
Counter create counter
puts [counter currentcount]
counter increment
counter increment 5
puts [counter currentcount]
counter decrement
counter decrement 3
puts [counter currentcount]So that's pretty cool. That's seems about as dynamic as it gets. [define] reminds me of that TAHITI machine that rebuilt Agent Coulson's brain. [define] is a magical command.
Now, honestly, I was about to move on to the OO classic, "A home is a house with a family and a pet," but I'm feeling inspired.
namespace import oo::*
class create Organization {
variable taxID members
constructor {taxid} {
set taxID $taxid
}
method getTaxID {} {
return $taxID
}
}
class create SecretSpyOrganization {
superclass Organization
variable alignment
constructor {taxid align} {
set alignment $align
next $taxid
}
method getAlignment {} {
return $alignment
}
}
SecretSpyOrganization create SHIELD 007 good
SecretSpyOrganization create HYDRA 666 evil
puts [SHIELD getTaxID]
puts [HYDRA getAlignment]