[Baypiggies] Mini languages
Dennis Allison
allison at shasta.stanford.edu
Sun May 7 21:11:56 CEST 2006
Ken --
"a simple language translator" is not comensurate with "a superset of C++"
Some might say it's an oxymoron.
It looks like what you are wanting to do is to build a little lanaague
that you parse and output C++ object code. I do that sort of thing all
the time; and I am sure I am not alone. There are a bunch of different
parsing tools available in python, but if the language really is simple,
I'd go for a recursive descent parser written in python; if it is
expression heavy, you might want to do expressions by some bottom-up
scheme. Trees make a nice intermediate form. The big question is what
you want to do in terms of optimization. With a C++ target, I suppose
that you leave that to gcc.
You might want to reconsider your approach and use python as the language
and C++ extensions to do the heaavy lifting, if necessary. You could, of
course, make custom extensions for specific problems as an optimization.
On Sun, 7 May 2006, Ken Seehart wrote:
> I want to implement a simple language translator (a superset of C++),
> but I haven't done anything of this kind since college (a couple decades
> ago). I would like to use python tools as much as possible.
>
> NICL code -> [C++ preprocessor (gcc)] -> [NICL translator] -> [C++
> compiler (gcc)] -> object code
>
> The translator needs to be able to parse special non-c++ syntax to
> generate c++, and leave other code intact.
>
> More documentation on my project here:
>
> http://www.seehart.com/neuralintegrator.com/documentation/ni_book/defining_cell_types.st
>
> I could almost get by with just a python script using regular
> expressions (my grammar is simple enough), but I need to know a certain
> amount of contextual information. E.g., if I am parsing "cellclass
> mycell { ... }", the contents between the braces must be processed
> accordingly. This means I have to know when I reach the closing brace
> (which I can't do with regular expressions). However, I'm sure I could
> do a prototype this way, using the assumption that the a closing brace
> on a class matches "^};", but that would be just plain sloppy :-)
>
> So I think one way or another I'm stuck with implementing an LALR parser.
>
> I'm wondering if there is anyone in this community with experience doing
> this kind of thing.
>
> - Ken Seehart
>
>
--
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