[plt-dev] some Racket proposals & implementation

I cited this as an (silly) example of making it even shorter.

(If Matthew says it's all easy to do, I will withdraw my objections.)



On Apr 5, 2010, at 10:31 AM, Robby Findler wrote:

> Something like that seems okay. I thought the proposal was for:
>
> (define (ufo #:posn p #:vel [vel (velocity 0 0)]))
>
> to be a define-struct (because it has no body).
>
> Robby
>
> On Mon, Apr 5, 2010 at 9:28 AM, Matthias Felleisen <matthias at ccs.neu.edu 
> > wrote:
>>
>> While I agree with your sentiment -- not changing so much right now  
>> --
>> I disagree with the overall evaluation. I think
>>
>>  (define-struct ufo moving-object (#posn p #vel (velocity 0 0)))
>>
>> very appealing per se, also with the even shorter syntax of using  
>> just
>> define. The regularity of having both function headers and struct  
>> headers
>> use the same grammar is great. (It may even pacify the grumpy old  
>> men of
>> Scheme standards.) I just don't think we're ready for it now if we  
>> want
>> lots of files to start with #lang racket.
>>
>> -- Matthias
>>
>>
>>
>>
>>
>> On Apr 5, 2010, at 10:21 AM, Robby Findler wrote:
>>
>>> I dislike this change. Brainfuck is very lightweight language too  
>>> (by
>>> the measures of lightweightness I've seen here recently), lets not
>>> forget.
>>>
>>> In more politic words, it seems like making function definitions and
>>> structure definitions look so similar to each other is just asking
>>> Racket programmers to get confused.
>>>
>>> Robby
>>>
>>> On Mon, Apr 5, 2010 at 9:18 AM, Matthias Felleisen <matthias at ccs.neu.edu 
>>> >
>>> wrote:
>>>>
>>>> On Apr 4, 2010, at 10:37 PM, Eli Barzilay wrote:
>>>>
>>>>> On Apr  4, Matthias Felleisen wrote:
>>>>>>
>>>>>> On Apr 3, 2010, at 8:19 PM, Matthew Flatt wrote:
>>>>>>
>>>>>>> I like
>>>>>>>  (define-struct (a x y) #:super b)
>>>>>>> much better than the current
>>>>>>>  (define-struct (a b) (x y))
>>>>>>> but I'm not sure that it's worth changing.
>>>>>>
>>>>>> The issue I brought up in Boston was the 'heaviness' of the  
>>>>>> looks of
>>>>>> our code, which to some extent is caused by long names. Going  
>>>>>> from
>>>>>> (make-a 0 1) to (a 0 1) is a good weight loss. The above seems to
>>>>>> call for trouble for a minor advantage.
>>>>>
>>>>> I think that there *is* some weight loss here too -- one that is
>>>>> similar to loss of moving from `mzlib/kw' to the current syntax.
>>>>> Specifically, there's a whole bunch of struct features that you  
>>>>> get
>>>>> with no need to remember anything more than "use `define-struct'
>>>>> instead of `struct'".  It's also the same kind of win as "use  
>>>>> `for/*'
>>>>> instead of `let'" that makes the current iterators so good (as  
>>>>> opposed
>>>>> to the srfi or the swindle or the CL syntaxes).
>>>>
>>>>
>>>> Yes, using a plain function header to specify structures (without  
>>>> body)
>>>> is very nice because you get all these things (keywords,  
>>>> initialization)
>>>> for free. But then we're back to the balance of change vs getting  
>>>> Racket
>>>> out. -- Matthias
>>>>
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>>
>>