Looking for a cure for weird scope/memory of variables

[Mojca Miklavec]

Hi,

the more I read this thread, the more I find it all confusing.

Can someone suggest the best solution in case of this concrete example?
   https://trac.macports.org/browser/users/mojca/ports/science/geant/Portfile

The variable ${geant.data_versions} works ok (but probably some nicer
code), but ${geant.datadir}, particularly inside destroot of
geant4-${geant.version}-data is problematic.

Thank you,
    Mojca

On Wed, Jul 10, 2013 at 12:25 AM, Lawrence Velázquez wrote:
> On Jul 9, 2013, at 5:19 PM, Joshua Root wrote:
>
>> On 2013-7-10 03:56 , Clemens Lang wrote:
>>> On Tue, Jul 09, 2013 at 07:32:03PM +0200, Gustaf Neumann wrote:
>>>> foreach {foo.version foo.string} ${foo.versions} {
>>>>    subport foo-${foo.version} [subst {
>>>>        pre-fetch {
>>>>            system "echo ${foo.version}"
>>>>        }
>>>>        fetch {}
>>>>        extract {}
>>>>        use_configure no
>>>>        build {}
>>>>        destroot {}
>>>>    }]
>>>> }
>>>
>>> I assume there is no sane way to guess what the user wants and somehow
>>> integrate this into the subport (and pre-fetch, etc.) procs, is there?
>>>
>>> We could have a -subst switch, though:
>>>  subport -subst {
>>>    code
>>>  }
>>
>> No need for that; using quotes instead of braces will achieve the same
>> thing. The trouble comes of course if you want to substitute some
>> variables at definition time and others at runtime (or at the top level
>> of the subport but not inside the pre-fetch or other internal
>> brace-wrapped string). I guess you could use 'format' on the body.
>
> For selective definition-time substitution, you could use string map (http://wiki.tcl.tk/37332#pagetoc04c6ab3f):
>
>     foreach {foo.version foo.string} ${foo.versions} {
>         set script {
>             subport foo-${foo.version} {
>                 pre-fetch {
>                     system "echo ${foo.version}"
>                 }
>                 fetch {}
>                 extract {}
>                 use_configure no
>                 build {}
>                 destroot {}
>             }
>         }
>         set script [string map [list \${foo.version} [list ${foo.version}]] $script]
>         eval $script
>     }