[plt-scheme] [redex] language keywords

Oh, great!

Robby

On Thu, Jun 3, 2010 at 8:12 AM, Eric Tanter <etanter at dcc.uchile.cl> wrote:
> Thanks all,
>
> I'm moving to 'where' everywhere, and it seems to work. It's even much more readable with where clauses than with the collections of (nested) term-lets that I had.
>
> -- Éric
>
>
> On Jun 3, 2010, at 2:36 AM, Robby Findler wrote:
>
>> It would be good to avoid term-let, I think, if you can use things
>> like 'where' in the reduction relation instead. But we'd probably need
>> to see an example use if you don't see how to do the transformation.
>>
>> Robby
>>
>> On Wed, Jun 2, 2010 at 9:51 PM, Eric Tanter <etanter at dcc.uchile.cl> wrote:
>>> Yes, I do use term-let and that's (at least up to now) exactly where the
>>> problem manifests!
>>>
>>> Should I be using something else?
>>>
>>> -- Éric
>>>
>>> On Jun 2, 2010, at 22:40, Casey Klein <clklein at eecs.northwestern.edu> wrote:
>>>
>>>> On Wed, Jun 2, 2010 at 9:21 PM, Carl Eastlund <cce at ccs.neu.edu> wrote:
>>>>>
>>>>> On Wed, Jun 2, 2010 at 10:15 PM, Casey Klein
>>>>> <clklein at eecs.northwestern.edu> wrote:
>>>>>>
>>>>>> On Wed, Jun 2, 2010 at 9:02 PM, Eric Tanter <etanter at dcc.uchile.cl>
>>>>>> wrote:
>>>>>>>>>
>>>>>>>>> Is there something as simple/direct as the list of keywords in
>>>>>>>>> syntax-rules/syntax-case?
>>>>>>>>> If not, any alternative suggestion?
>>>>>>>>>
>>>>>>>>> Thanks!
>>>>>>>>>
>>>>>>>>> -- Éric
>>>>>>>>
>>>>>>>> Take a look at variable-prefix.  In my latest Redex work, variables
>>>>>>>> all start with x, y, or z, and I just have to avoid any keywords that
>>>>>>>> start with those.
>>>>>>>
>>>>>>> Thanks Carl,
>>>>>>>
>>>>>>> I'm using these as well, actually.
>>>>>>> A problem I have is that, for readability, I have a non-terminal which
>>>>>>> is define as (x >> x) where '>>' is a keyword. I know I could just use (x x)
>>>>>>> for exactly the same, but it does enhance readability.
>>>>>>> The problem is that >> is considered as a pattern variable...
>>>>>>>
>>>>>>> with macros I could just say:
>>>>>>> (syntax-rules (>>)
>>>>>>>  ((x >> x) ...))
>>>>>>>
>>>>>>> Any idea?
>>>>>>>
>>>>>>
>>>>>> I don't follow. The variables in a Redex pattern are always named
>>>>>> after non-terminals, so I don't see how >> could be treated as a
>>>>>> pattern variable.
>>>>>>
>>>>>> Do you mean that >> matches one of your six classes of variables?
>>>>>
>>>>> Is it possible Eric is using one of the forms that match using
>>>>> syntax-case instead of the Redex pattern matcher?  Do term-let and
>>>>> where clauses still work that way?
>>>>
>>>> Oh, good thinking! term-let uses syntax-case, but where clauses no longer
>>>> do.
>>>>
>>>>> (And if not, Eric, what version of PLT Scheme are you using?)
>>>>>
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>
>