[racket] Plea for neologism (was: Re: letoverlambda)
On Wed, Nov 24, 2010 at 1:49 PM, John Clements
<clements at brinckerhoff.org> wrote:
>> On Wed, Nov 24, 2010 at 11:05 AM, Robby Findler
>> <robby at eecs.northwestern.edu> wrote:
>>> On Wed, Nov 24, 2010 at 12:55 PM, Joe Marshall <jmarshall at alum.mit.edu> wrote:
>>>>> On Nov 20, 2010, at 6:58 PM, Matthias Felleisen wrote:
>>>>>
>>>>>> Hygiene is a technical term. The idea is roughly that
>>>>>> the __macro system__ (as a whole) should respect the
>>>>>> lexical structure of your program.
>>>>
>>>> It is somewhat unfortunate that the name `hygiene' has caught
>>>> on here. It really ought to be called `lexical scoping' (with the
>>>> understanding that macros have no special permission to violate
>>>> lexical scope any more than lambda bindings do).
>>>
>>> You know about Oleg's macro called, bind-x-to-5 that has one
>>> subexpression does exactly its name claims, but in a hygenic macro
>>> system?
>
> Hang on... you're still using the term "hygienic" in the non-Felleisen way.
No I'm not.
> That is, if we accept that a hygienic system is one that has well-defined behavior but where you can bind new names when you explicitly ask to, then
>
> #lang racket
>
> (define-syntax (bind-x-to-5 stx)
> (syntax-case stx ()
> [(_ exp)
> #`(let ([#,(datum->syntax stx 'x) 5])
> exp)]))
>
> (bind-x-to-5 x)
>
> ...is a legal macro in a hygienic macro system.
Sure.
But Oleg's macro doesn't do that.
Robby