Bugfix #778: Flag for entry into for loop after range has been processed

[fknauf]

Fixes #778, and it's possibly relevant for #432.

I ran the regression tests and spotted no differences in output. I also have a bash script now to run the tests on a Linux machine, should I put that in here as well?

[JohelEGP]

Thank you.
The approach looks correct to me.
Can you add these tests for confirmation?

issue_778: (args) = {
   for :() args$;() do (i) _ = i;
   for :(x) x;(args) do (j) _ = j;
   for :(x) x;(args) next _ = :() args$;() do (k) _ = k;
   for :(x) x;(args) next _ = :(x) x;(args) do (l) _ = l;
}

[fknauf]

I added the tests. The output was compileable and looked reasonable to me. Then I merged the new state of the main branch and ran the tests again. All tests are green, so it seems to work and not break anything.

[JohelEGP]

Thank you for this.

This is definitely the right approach.
If things are not marked right before they are needed, you end up needing to use stacks.
That's because function expressions are very general,
so in the most extreme case you can have a for loop before an outer's for loop do.
Without stacks, that would erase any state before the outer's for loop do.
Marking things right before is simpler than stacks and correct by construction.

[fknauf]

I'm not 100% sure I agree that flags like this one are the correct way to handle parsing context like this, but it seemed like the least invasive way to handle it. In a new design I'd maybe consider encoding information like this in the parse tree so that the safety of the expression becomes an S-attribute.

[hsutter]

(Catching up with PRs, sorry for the delay)

Thanks for your pull request! It looks like this may be your first contribution to cppfront. I've sent the Contributor License Agreement (CLA) to your email, and once it's signed I can look at your pull request. Thanks again for your contribution.

[hsutter]

Thanks! I just made a minor style tweak to follow the style I was already using for such so-far-very-occasional extra information.