Announcement on news:comp.lang.tcl on 01-Oct-2007:
I'm very pleased to announce that TclOO version 0.1 is now released. It's hosted in the Tcl project at SourceForge, so you can download the source package from: http://sf.net/project/showfiles.php?group_id=10894&package_id=247402
It requires Tcl 8.5b1 to build and operate; see the enclosed README.txt for details on how to build this TEA-based package. No promises on whether I'll do a binary package for any platforms as yet. :-)
Details about this package can be found in the Wiki, naturally, at http://wiki.tcl.tk/TclOO and any problems should be reported using Tcl's issue trackers at http://sf.net/tracker/?group_id=10894&atid=110894 with the summary field prefixed by "TclOO:".
SDW: For those of you following at home, TclOO is now in the Teacup package manager (thanks Jeff!). If you have ActiveTcl 8.5 beta 9 or greater run: teacup install TclOO, and try it out for yourself.
RS tried, and failed at first attempt - needed teacup proxy proxyname port before, then it worked. For the impatient, here's the simple example from README.txt (which by the way does not come with the installed package, but can be found on http://tcl.cvs.sourceforge.net/tcl/oocore/ ):
oo::class create summation {
constructor {} {
variable v 0
}
method add x {
variable v
incr v $x
}
method value {} {
variable v
return $v
}
destructor {
variable v
puts "Ended with value $v"
}
}
set sum [summation new]
puts "Start with [$sum value]"
for {set i 1} {$i <= 10} {incr i} {
puts "Add $i to get [$sum add $i]"
}
summation destroywhich gives (only last lines shown):
... Add 10 to get 55 % summation destroy Ended with value 55
Should you see the error message
attempt to provide package TclOO 0.1.1 failed: package TclOO 0.1 provided instead
it helps to refetch the HEAD, rerun configure, and do a clean build. The test suite is at http://tcl.cvs.sourceforge.net/tcl/oocore/tests/oo.test and passes well on my Win XP/8.5b1 setup.
Update: Without teacup, I took the source distro http://downloads.sourceforge.net/tcl/TclOO0.1.tar.gz?modtime=1191249015&big_mirror=1 which falied to make. Following tclguy's advice, I obtained http://tcl.cvs.sourceforge.net/tcl/oocore/TclOO.rc , created a win directory in the sources and put it there, and almost presto... TclOO runs on old W95 too (at least passes all 85 tests in oo.test :^)
DKF 18 May 2007: At last, after a long hiatus, I've had enough time to finish getting the code smashed into shape as a loadable TEA extension. It works for me (as in: successfully runs the test suite) on both Windows and Linux (built with gcc on both) as long as you're using a recent-enough version of Tcl (i.e. more recent than 8.5a6; there was an internal API that had to be modified to prevent crashes when info frame was used inside a method). Right now, there's no distribution, but you can check it out of cvs using:
cvs -d:pserver:[email protected]:/cvsroot/tcl co oo
To build, just change into the base directory of the code and do a configure/make combo.
(Also includes experimental support for building a starkit version, as long as you have sdx on the path. Let me know if it works or not, as it doesn't work locally for other ugly reasons.)
Note - do not check out the oocore module; that's incomplete since it lacks the (required) TEA build support.
04jun07 jcw - Some notes on trying to build this extension:
install: /.../TclOO-0.1/library/*.tcl: No such file or directory
Ok, that woiked, great!
Now a usage question, if I may: is there some nice idiom for the following?
my variable {*}[info vars [namespace current]::*]IOW, set up methods to automatically have access to all object state as plain variables (as in Itcl). The above line would be added in front of all method definitions, using a small wrapper (am generating methods dynamically anyway).
This assumes that all variables are defined in the constructor.
escargo Does this use of variable contrast confusingly with the Tcl variable where something like that would assign the names of half the variables as the values of the other half of the variables?
jcw - Well, I'm just trying it out, so don't shoot me ;) - although so far I tend prefer this over the "variable" cmd.
escargo - I was just asking a question. It's just that having my variable work not like variable might be considered confusing.
jcw - Here's an example with some output which may help those who don't have TclOO yet:
oo::class create dog {
method a {} {
puts a1-[namespace current]
puts a2-[namespace path]
foreach x [namespace path] {
puts a3-$x-[info commands ${x}::*]
}
puts a4-[info vars [namespace current]::*]
my variable e
set e f
puts a5-[info vars [namespace current]::*]
}
self.method b {} {
puts b1-[namespace current]
puts b2-[namespace path]
foreach x [namespace path] {
puts b3-$x-[info commands ${x}::*]
}
puts b4-[info vars [namespace current]::*]
my variable e
set e f
puts b5-[info vars [namespace current]::*]
}
}
dog create fifi
fifi a
dog b
# Output:
# a1-::oo::Obj4
# a2-::oo::Helpers
# a3-::oo::Helpers-::oo::Helpers::self ::oo::Helpers::next
# a4-
# a5-::oo::Obj4::e
# b1-::oo::Obj3
# b2-::oo::Helpers ::oo
# b3-::oo::Helpers-::oo::Helpers::self ::oo::Helpers::next
# b3-::oo-::oo::InfoClass ::oo::class ::oo::InfoObject ::oo::object \
# ::oo::copy ::oo::define
# b4-
# b5-::oo::Obj3::eAs you can see, each class and each instance gets its own namespace. Note also that class Dog ended up as namespace Obj3, even though it was constructed with a specific name (which is not necessarily globally unique, though).
DKF: I've been experimenting for a while now with OO systems, and a my variable that brings every variable in the object into scope is probably not what you want as it causes great problems in subclasses (i.e. clashes between subclasses' variables and local variables). Instead, I think that being able to pick up all the variables defined within a particular class would be far more useful. OTOH, it's not at all trivial to implement (I think I expose enough API that it can be done through the use of class metadata, but I'm not certain) so I'm not in a hurry to change things.
It was a deliberate decision to make my variable different from variable; the latter has syntax that is almost never what anyone wants, and so is a priori suboptimal. Hence I went for something that was more likely to be what you need. :-)
(escargo - Well, I wondered if you did it on purpose, and you did. And I see it was for what you think is a good reason.)
Also, as noted, the internal namespaces have names that are not necessarily those of the created object, and their names are deliberately not documented (i.e. they could change between point releases with no warning). Use the introspection facilities to go from one to the other.
APW 2007-06-05 @ jcw: I am working on an extended version of dkf's code suitable for Itcl, which would have solutions for some of the problems you have mentioned above. For example I am using "apply" and "namespace upvar" and "namespace unknown" to generate Itcl methods, which have access to all the class variables in the class hierarchy (if they are not private) etc. Using only the name of a variable as in Itcl is possible, same for call of Itcl methods without the "my" in front. If you are interested please contact me directly, the implementation is not yet ready for real testing.
@ dkf: If I know what I really need additionally for Itcl I will contact you and we can try to perhaps get a merged version. At the moment all my modifications are additional functionality so that the original functionality should work as before with also running all your tests without problems.
DKF: The following example is ripped from the documentation of next:
oo::class create cache {
filter Memoize
method Memoize args {
# Do not filter the core method implementations
if {[lindex [self target] 0] eq "::oo::object"} {
return [next {*}$args]
}
# Check if the value is already in the cache
my variable ValueCache
set key [self target],$args
if {[info exist ValueCache($key)]} {
return $ValueCache($key)
}
# Compute value, insert into cache, and return it
return [set ValueCache($key) [next {*}$args]]
}
method flushCache {} {
my variable ValueCache
unset ValueCache
# Skip the cacheing
return -level 2 ""
}
}
oo::object create demo
oo::define demo {
mixin cache
method compute {a b c} {
after 3000 ;# Simulate deep thought
return [expr {$a + $b * $c}]
}
method compute2 {a b c} {
after 3000 ;# Simulate deep thought
return [expr {$a * $b + $c}]
}
} puts [demo compute 1 2 3] → prints "7" after delay
puts [demo compute2 4 5 6] → prints "26" after delay
puts [demo compute 1 2 3] → prints "7" instantly
puts [demo compute2 4 5 6] → prints "26" instantly
puts [demo compute 4 5 6] → prints "34" after delay
puts [demo compute 4 5 6] → prints "34" instantly
puts [demo compute 1 2 3] → prints "7" instantly
demo flushCache
puts [demo compute 1 2 3] → prints "7" after delayWay cool, great separation of functionality. Next step: a Metakit backed cache? ;) -jcw
DKF: I've thought more about this, and have written an Aspect Support Class for TclOO.
APW 2007-06-06 For discussion of Itcl related topics for a new implementation based on this TIP see tclOO missing features for Itcl
DKF 20-Sept-2007: As seen in my Tck2k7 paper, TclOO is really quite fast. Here's those performance figures (correct with 8.5b1 on my ancient laptop).
| OO System | Objects Made (s⁻¹) | Method Calls (s⁻¹) |
|---|---|---|
| TclOO 0.1 | 32800 | 206000 |
| itcl 3.4.0 | 22500 | 128000 |
| XOTcl 1.5.5 | 18500 | 87500 |
| Snit 2.1 | 2080 | 54700 |
| Snit 1.2 | 1020 | 24700 |
| stooop 4.4.1 | 13900 | 26700 |
Notes: It turns out that stooop non-virtual methods are much faster, but they're not comparable with the other methods as they do not allow overriding of the method by subclasses, so I used the (comparable) virtual methods instead, which are much slower.
The script used to create the performance data is below. (Well, I actually did it interactively over a few runs, so I don't warrant that this script will really work...)
package require Tcl 8.5b1
proc cps {script {iters 100000}} {
set s [uplevel 1 [list time $script $iters]]
set cps [expr {1/([lindex $s 0]/1e6)}]
puts "$cps calls per second of: $script"
}#──────────────────────────────────── puts "using Itcl..." package require Itcl 3.4 namespace path itcl
class foo {
variable x
constructor {} {
set x 1
}
method bar {} {
set x [expr {!$x}]
}
}
foo f
cps {f bar}
delete object f
cps {delete object [foo f]} 10000
delete class foo#──────────────────────────────────── puts "using XOTcl..." package require XOTcl 1.5.5 namespace path xotcl
Class create Foo
Foo parameter x
Foo instproc init {} {
my set x 1
}
Foo instproc bar {} {
my instvar x
set x [expr {!$x}]
}
Foo create f
cps {f bar}
f destroy
cps {[Foo create f] destroy} 10000
Foo destroy#──────────────────────────────────── puts "using TclOO..." package require TclOO 0.1 namespace path oo
class create foo {
constructor {} {
variable x 1
}
method bar {} {
variable x
set x [expr {!$x}]
}
}
foo create f
cps {f bar}
f destroy
cps {[foo create f] destroy} 10000
foo destroy#──────────────────────────────────── puts "using snit..." package require snit 2.1
snit::type foo {
variable x
constructor {} {
set x 1
}
method foo {} {
set x [expr {!$x}]
}
}
foo create f
cps {f bar}
f delete
cps {[foo create f] destroy} 10000
foo destroy#──────────────────────────────────── puts "using stooop..." # Must go last because it plays games with proc which might disturb the # performance of other OO systems. Note that stooop has both virtual and # non-virtual methods, with very different performance profiles. The virtual # ones are much more comparable in capability to other OO systems... package require stooop 4.4.1 namespace path stooop
class foo {
proc foo {this} {
set ($this,x) 1
}
proc ~foo {this} {}
virtual proc bar {this} {
set ($this,x) [expr {!$($this,x)}]
}
proc bar-nv {this} {
set ($this,x) [expr {!$($this,x)}]
}
}
set f [new foo]
cps {$f bar}
cps {$f bar-nv}
delete $f
cps {delete [new foo]} 10000See also TIP #257: Object Orientation for Tcl - Playing with TclOO
LV 2007 Oct 01 So, what is the purpose of this code? Is the intention that people will write Tcl object oriented code with this extension? Or is it intended to be a framework for existing and future OO extensions to be more powerful?
DKF: It's a core for other OO extensions, but in order to do that job properly it also needs to be a basic OO framework itself.