Re: [GSoC] Bourne-shell compiler front-end for Guile

[ludo@gnu.org (Ludovic Courtès)]

Efraim Flashner <efraim@flashner.co.il> skribis:

> On Mon, 21 Mar 2016 23:27:25 +0100
> ludo@gnu.org (Ludovic Courtès) wrote:
>
>> Hi Efraim,
>> 
>> Thanks for your proposal!
>> 
>> This project can be pretty fun, I think, and quite rewarding if it
>> indeed allows us to get rid of a bunch of bootstrap binaries.
>> 
>> As I see it, the project covers mostly two areas:
>> 
>>   1. Lexing & parsing.  This compiler front-end will need a real parser
>>      for the Bourne shell syntax, notably semicolon-separated command
>>      sequences, pipes, brace-delimited blocks, functions, variables, and
>>      ‘test’ and ‘[’.
>> 
>>      The available tools could be SILex + (system base lalr) (the latter
>>      is part of Guile, the former is maintained separately; a copy can
>>      be found in Guile-RPC for instance.)
>> 
>>   2. Run-time support: redirections, pipes, background execution, C-c
>>      (SIGINT) and C-z (SIGTSTP), globbing, and so on.
>> 
>>      Guile provides just the basic here, and a little more with (ice-9
>>      popen).  Scsh and its Guile port(s) provide a lot of that, so it
>>      might be a good idea to see what can be stolen from these.
>> 
>> It may be that some of your CS classes cover some of this ground (a
>> fairly common programming project here at university is to implement a
>> small shell precisely because it covers several areas.)
>> 
>> How does that sound?
>> 
>> Perhaps one way to get started would be by looking at the available
>> tools for #1, and experimenting with hacks for #2, possibly borrowing
>> code from Scsh.
>> 
>> Thoughts?
>
> Sounds like lots of fun, I'm really looking forward to it. And it sounds like
> I'll need to dive deeper into bash to see what I get to implement

I guess a related question is how confident/familiar you feel with the
two areas above.  The agenda could be adjusted as a function of that.

Thanks,
Ludo’.