Re: nyacc 0.65.0 released

[Christopher Allan Webber]

Matt Wette writes:

> On Dec 30, 2015, at 6:35 AM, Ludovic Courtès <address@hidden> wrote:
>>> Demo:
>>> Use C parser and pretty printer to clean up C expressions (e.g., remove 
>>> unneeded paren’s):
>> 
>> The demo is already quite impressive!
>
> Thanks.

I agree.  Holy damn, this looks incredible.

>> What subset of C99 and GNU99 is currently supported?
>
> I can’t remember if any C99 items are not in.  I do not have any GNU99
> extensions in there.  However, this is not a faithful parser for C99.
> The purpose is not to compile, but to generate translators and
> auto-coders.  I have built the parser with the following features:
> 1) The c-preprocessor parsing is merged in with the lexical analyzer.
> 2) The parse tree is “file oriented”, so that you can track what
>    elements are in the top-level file.
> 3) The parser will parse comments.
>
> so
> #ifdef ABC
> #include “xyz.h”
> #endif
> foo_t x;   /* this is a decl */
>
> comes out
> (trans-unit
>   (cpp-stmt (if (defined "ABC")))
>   (cpp-stmt
>     (include
>       "\"xyz.h\""
>       (trans-unit
>         (decl (decl-spec-list
>                 (stor-spec (typedef))
>                 (type-spec (fixed-type "int")))
>               (init-declr-list (init-declr (ident "foo_t")))))))
>   (cpp-stmt (endif))
>   (decl (decl-spec-list (type-spec (typename "foo_t")))
>         (init-declr-list (init-declr (ident "x")))
>         (comment " this is a decl ")))
>
> and the pretty-printer generates
> #if defined(ABC)
> #include "xyz.h"
> #endif
> foo_t x; /* this is a decl */

Still super cool.

>> What are you aiming for with the tree-il conversion?  That sounds
>> interesting.  :-)
>
> The purpose of the tree-il conversion is to support “,L <langauge>” at
> the guile prompt.  And the tree-il code is done for javascript and a
> simple calculator, not C.  I just tried the javascript and it is not
> working, but here is a small demo with the simple calculator.  The
> calc files (parser, compiler and spec) are included below.
>
> scheme@(guile-user)> ,L calc
> Happy hacking with calc!  To switch back, type `,L scheme'.
> calc@(guile-user)> a = 3 + 4
> calc@(guile-user)> ,L scheme
> Happy hacking with Scheme!  To switch back, type `,L calc'.
> scheme@(guile-user)> a
> $1 = 7

That's really interesting.  Do you have more specific applications in
mind beyond this?