[plt-scheme] [redex] language keywords

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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