C like syntax

[Keisuke Nishida <kxn30 at po dot cwru dot edu>]

Marius Vollmer <mvo@zagadka.ping.de> writes:

> I don't like that a simple C statement like
> 
>     obj->x++;
> 
> turns into
> 
>     (set! (gto-canvas-x obj) (1+ (gto-canvas-x obj)))
> 
> with my style of choosing accessor names, but I hope to write this
> like
> 
>     (with-struct-accessors ((gto-canvas x obj))
>       (set! x (1+ x)))
> 
> in the future.  If you regard the `with-struct-accesors' line as
> analogous to a (unavoidable) type declaration of obj in C, this is not
> at all bad.
> 
> So to summarize: I don't think we should change the syntax of Guile to
> make accessors different from other functions.  However, there should
> be enough hooks into the reader to let people bend the syntax quite
> badly if they want to.

Is it possible to use C like syntax like this by using a transformer
or something?

  (let ((i #f) (v (make-vector 5)))
    {
      for (i = 0; i < 5; i++)
        v[i] = obj->x;
    })

turns into

  (let ((i #f) (v (make-vector 5)))
    (set! i 0)
    (while (< i 5)
      (vector-set! v i (x obj))
      (set! i (+ i 1))))

If this can be done, it may be useful when one want to write many
mathematical expressions.

-- Kei