Re: [gentoo-portage-dev] Google Summer of Code: Bash AST and grammar

[Sebastian Pipping]

On 07/21/10 15:49, Nathan Eloe wrote:
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> Hello portage developers
>
> My name is Nathan Eloe, and I'm working on a Google Summer of Code
> project in which I'm writing a library that will create an Abstract
> Syntax Tree of the bash grammar.  In essence I am recreating the bash
> grammar and structuring it as an AST.
>
> I am writing to you because you have shown interest in
> this project.  I have attached a bash script which demonstrates the
> supported functionality of the grammar thus far and the resulting AST.

Nice, you have covered quite a few constructs alraedy.


> I would greatly appreciate input on the tree

I'm unsure if such a big file and tree is good to handle.
I propose to split this test suite to many small cases.


> as well as insight into
> missing functionality you might see.

A few things I haven't seen, yet:

   # Adjacent changes in quotation
   echo "abc"'"'"def"  # Makes abc"def

   # Escape sequences like ..
   echo "abc\"def"

   # Invocation from ibnside strings
   echo "foo $(echo foo), bar `echo bar`"

   # Heredocs (and their variations ..)
   cat <<EOF >/dev/stdout
   1
   2
   EOF

   # Construct of $((..))
   # Refs to variable withzout "$" upfront
   z=3; echo $((z+3))

Best,



Sebastian