Re: [TCLCORE] End of Votes

[Hemang L. <hl...@ci...>]

Jan Nijtmans wrote:
> 2008/12/11 Hemang Lavana <hl...@ci...>:
>   
>> It's not as simple as doing "package provide" twice when tcl modules are
>> involved. This is how our developers initially started out to support
>> multiple cases for our packages. They had multiple "package provide"
>> statements in their library to support FooBar, foobar and fooBar. However,
>> when we started creating tcl modules for these packages, the "package
>> provide" trick would no longer work.
>>     
>
> Here we are talking about packages implemented in C, not Tcl
> modules, which has a lot of additional handling. Anyway, I'm very
> interested to hear what the problem was, but I am confident
> that for the situation we are talking about here, it doesn't apply.
>   
I was talking in the context of original TIP. Let me elaborate on our 
problem. We have a package FooBar and we would like to support 3 styles 
of package names: FooBar (original name), fooBar (camelcase) and foobar 
(lowercase). Our pkgIndex.tcl file for this pkg was written as follows:

# Begin pkgIndex.tcl
set pkg_version 1.1
foreach pkg_name {FooBar fooBar foobar} {
    package ifneeded $pkg_name $pkg_version "
           source foobar-file1.tcl
           source foobar-file2.tcl
           #...
           package provide $pkg_name $pkg_version
    "
}
# End pkgIndex.tcl

Some developers have also used the following style instead:

package ifneeded foobar $pkg_version "
      package require FooBar $pkg_version ;# bug here, need to specify 
-exact option
      package provide foobar $pkg_version
"

The pkgIndex.tcl file and the foobar-*.tcl files were distributed to the 
users and they could load the pkg with one of the 3 pkg names. We 
started using tcl modules since it makes it easier to deploy -- only 
single file is required to be given to the user. However, for such 
packages, we have to create 3 tcl modules files: FooBar-1.1.tm, 
fooBar-1.1.tm and foobar-1.1.tm and ask the users to install all the 3 
TM files. Having multiple "package provide" stmts in a single TM file 
doesn't work:

rtp-lds-016:73> pwd
/auto/wshlavana/ats5.0-main/lib/tcl8/8.4
rtp-lds-016:74> ls
FooBar-1.1.tm
rtp-lds-016:75> tclsh
% package require foobar
can't find package foobar
% package require FooBar
1.1
% exit
rtp-lds-016:76> cat FooBar-1.1.tm
package require Tcl
namespace eval foobar {}
proc ::foobar::print {args} {
    puts "FooBar 1.1: $args"
}
package provide FooBar 1.1
package provide foobar 1.1
rtp-lds-016:77>

If package names are made case-insensitive, then it resolves all these 
issues. Given that the original TIP did not pass due to backward 
compatibility concerns, I am proposing an alternate solution to let the 
developers decide whether their package name should be case-sensitive or 
not.

> Anyway, thanks for your remarks. Your proposal might
> be a good solution, but it's too late for Tcl 8.6.
>   
It may be late for 8.6 but if we agree upon one approach, then there can 
be feature parity between core tcl and ActiveTcl versions.

Thanks,
Hemang.