Re: The beauty of LATEX

On 10/23/2011 7:57 PM, Dave Abrahams wrote:
> 
> on Sat Oct 22 2011, Joel de Guzman <joel-AT-boost-consulting.com> wrote:
> 
>> On 10/23/2011 7:49 AM, Joel de Guzman wrote:
>>> On 10/23/2011 4:15 AM, Dave Abrahams wrote:
>>
>>>> Especially if you're inspired by S-expressions, I can't imagine any good
>>>> excuse to invent a new syntax when lisp already has a syntax for this
>>>> sort of thing.  If we need to use square brackets instead of round ones
>>>> for legacy (or other) reasons, that's fine, but I don't at all see why
>>>> it makes sense to choose a syntax where of all things there's no outer
>>>> set of parens around the entire
>>>> function/macro/template/whatever-you-call-this-thing.  Why not do this:
>>>>
>>>>   [def foo[a] [a]]
>>>
>>> You are right Dave. I totally mixed it up! My concern was legacy
>>> Qbk code. I wanted something that can be applied to legacy code
>>> using simple grep. But I fumbled and mixed it up. I see that
>>> the old syntax has the syntax you wrote! I'll fix it.
>>
>> Following scheme/lisp more closely, that should be:
>>
>>   [def [foo a] [a]]
> 
> 
> I don't think so, at least not for lisp.  I don't know Scheme, but this
> works in lisp:
> 
>   (defun identity (a) a)  (assert (eq (identity 'bar) 'bar))
>   (defun foo (a) (list a)) (assert (equal (foo 'bar) '(bar)))
>   (defun foo (a) `(,a)) ; alternate spelling

Here's Scheme's define:

http://tinyurl.com/68r8a7d

E.g.:

(define (factorial n)
  (if (<= n 0) 1
    (* n (factorial (- n 1)))))

>> (Fine. That should still be grep-able).
>>
>> Now we have it very close to scheme including the dot notation
>> for variable args. E.g.
>>
>>   [decl [table title . rows]]
> 
> Dot notation doesn't mean variable arguments in lisp.  It's a cons
> operation.
> 
>     a . b == (cons a b)

Here's var-args in RScheme:

  http://tinyurl.com/3duefnd

There are lots of Scheme and Lisp-ish syntax variants and
dialects. These dialects have conflicting var-args syntax.
We'll just have to choose one.

>> and lambda. E.g.:
>>
>>   [lambda [x] [dup [x]]]
> 
> This one looks just like lisp to me.

Ok.

Regards,
-- 
Joel de Guzman
http://www.boostpro.com
http://boost-spirit.com