About sweet-expression

[Nala Ginrut]

I try to port sweet-_expression_ to newest Guile. Fortunately, the author wrote a compatible version for old Guile in 2008. So I just try to rewrite part of it for some obvious reasons. It woks fine now.

Though some guys doesn't like sweet-_expression_ at all (OK, they're real Lispers! But me too ;-)). I'm not a big fan to write Scheme like this:

-----------------------

define fibfast(n)  

  if {n < 2}       

    n

    fibup(n 2 1 0)

-----------------------

But I think it maybe useful for newbies especially came from Python of C. If we can fix the problems which I'll mention later, I expect it to be added as inner language support.

I put it here, if you're interested, please checkout here:

git://gitorious.org/nacre/guile-sweet.git

It supports Modern & Sugar both. You may read the README and try the example.

But there're some problems for the original implementation, so I didn't format a patch. I think there should be something to be fixed.

1.  The author's comment shows that we don't need to re-implement a reader if our reader treats "[]" and "{}" as delimiter.  But seems "{}" is not delimiter in current Guile. Mark Weaver said it should be fixed. 

2. And the second suggestion of Mark Weaver is we *must* try the Guile inner reader tools and keep some information if there's errors happened. I think it's a more worthy consideration. The current sweet is too weak to be a productive thing. 

3. We don't have "nfx" macro in current Guile, so only simple infix _expression_ can be evaluated. Say, all the operators are homologous: 

{1 + 2 + 3} is simple infix _expression_

{1 + 2 - 3} is not.

Anyway, it's not a big deal, I'll fix it later. But I'm not sure whether it should be in Guile or in app? Since the author use "nfx" directly, maybe it's a common thing we missed?