Re: scoped crm114 script variables --> in case you were wondering about match/bound vars, or: two mind altering substances that come out of MA, USA

On Thu, Feb 26, 2009 at 01:15:02PM +0100, Ger Hobbelt wrote:

missing test:

>    :capture_func:
>    isolate (:z:) /abcdefghijklmnop/           # make :z: be local
>    match [:z:] /...(...).../  ( :: :a: )      # capture :a: into :z:
+    match [:z:] /......(...)/  ( :: :x: )      # capture :z: into :x:
>    match <keep> [:z:] /(......).../  ( :: :b: )      # capture :b: into :z:
>    output /:*:_cd:: :a: is :*:a:, :z: is :*:z:, :b: is :*:b:\n/
+    output /:*:_cd:: :x: is -:*:x:-\n/

and same output on :x: at level 0, where I'd expect just ':x:' since it 
wasn't already defined at level 0.

> This will produce on bleeding edge GerH, which has full support for
> scoped variables:
> 
> ------------------------
> 1: :a: is def, :z: is abcdefghijklmnop, :b: is abcdef
...
> crm114: *WARNING*
> Attempt to alter the value of a nonexistent variable, so I'm creating
> an ISOLATED variable.  I hope that's OK.  The nonexistent variable is:
> 3/3: ':z:'/':z:'
> 0: :a: is now, :z: is :z:, :b: is If it sprouts legs, I don't want to know
> ------------------------

so if you want globals, no extra flags, just go up at level 0 and set them
there; sensible, looks fine to me, on 1st pass :)

> and on vanilla it outputs this:
> 
> ------------------------
> 1: :a: is def, :z: is abcdefghijklmnop, :b: is abcdef
...
> 1: :a: is toodels, :z: is ook! ook! banana!, :b: is If it sprouts
> legs, I don't want to know
> 0: :a: is toodels, :z: is ook! ook! banana!, :b: is If it sprouts
> legs, I don't want to know
> ------------------------
> 
> Now, about those bound vars, you were saying? Did you expect :a: to
> end up like that after that alter-mod to :z:?
> I didn't.

me neither, I'd expect the former results for local/scoped vars; the latter
is simply coherent with vars being globals. 
Check with missing xample as well.

> And :b: also sees an interesting change, which isn't entirely sensible.

indeed; I'd expect just 'If it '

> Also note that here is a prime example of the more profound error
> checking done by GerH: alter isn't expected to have to act on a
> nonexistent var, so GerH (correctly) yaks about it, if ever so softly
> (not a trap, just a warning). vanilla just barges on.

no, in vanilla :z: gets defined by the ISOLATE in :capture_func:, shouldn't
throw an error.

> Last but not least: note the use of the internal :_cd:, which is used

sensible :)



-- 
paolo

------------------------------------------------------------------------------
Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA
-OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise
-Strategies to boost innovation and cut costs with open source participation
-Receive a $600 discount off the registration fee with the source code: SFAD
http://p.sf.net/sfu/XcvMzF8H