rewrite the stage2 parser to be recursive and adhere to the official grammar

[andrewrk]

I'm creating this issue in case any contributors want to take a stab at it.

Now that @Hejsil created the formal grammar, and now that we know recursion is OK, there are 2 things that need to happen to std/zig/parse.zig:

• rewrite it in recursive style so that it is easier to maintain
• adhere to the formal grammar

It's a fairly large project, that will probably take a couple weeks for someone who isn't already familiar with the parser to do. You can look at src/parser.cpp and almost directly port the code.

[rayonix]

Has anyone started working on this rewrite? I have started looking at it but wanted to check. I'm new to Zig and thought this might be a good way to understand the compiler and language.

Also, is there any new information that would be helpful or important to know?

[hryx]

Hi @rayonix,

I already have a branch for this change with significant progress: master...hryx:stage2-recursive-parser

It's close to done, though I haven't opened a pull request yet; I'm aiming to do so by tomorrow or next week. If you want to take a look, comments are welcome, even before the PR is ready!

There are several other issues which would be good for newcomers, though I don't have any particular recommendations — someone else might.