(chore/fix) Elixir keywords need some serious help

[joshgoebel]

I know that this PR merely reformats the list, but it caught my attention because there are a lot of keywords in it that I have never seen in Elixir. Also let my starts by saying that I am not sure if there is a formal definition of a "keyword". I'm using that term rather intuitively.

As far as I know, those are not Elixir keywords at all:

• begin
• break (Inspect.Algebra.break/1 is a function in the standard lib, but it has nothing to do with breaking out of loops like it might do in other languages)
• defined
• ensure
• include
• module
• next (OptionParser.next/2 is a function in the standard lib, it has nothing to do with skipping to another iteration in a loop like it might do in other languages)
• redo
• retry
• return
• until
• while

I'm unsure about:

• self. It exists, but IMO it is a normal macro, not a keyword. I wouldn't expect it to be colored differently than other normal macros (like rem, round, trunc etc).
• then. It's a new macro added in Elixir 1.12 together with tap, I don't think those are keywords.
• with|0. I'm not sure what the pipe and zero mean here. with on its own is definitely a keyword.

Missing IMO:

• if case, cond, and unless qualify as keywords, if and else should too.
• if quote qualifies as a keyword, unquote and unquote_splicing should too.
• receive/after https://hexdocs.pm/elixir/Kernel.SpecialForms.html#receive/1
• try/rescue/catch/after https://hexdocs.pm/elixir/Kernel.SpecialForms.html#try/1
• raise https://hexdocs.pm/elixir/Kernel.html#raise/1
• reraise https://hexdocs.pm/elixir/Kernel.html#reraise/2

Originally posted by @angelikatyborska in #3207 (comment)

[joshgoebel]

there are a lot of keywords in it that I have never seen in Elixir.

I'm starting to think this grammar may just have been borrowed/copied from another long ago (as often happened)... it seems based on this feedback that it has many flaws.

with|0. I'm not sure what the pipe and zero mean here. with on its own is definitely a keyword.

The |0 is a signal that the keyword should have 0 relevance (vs the default of 1) because it's too common. This is to aid auto-detection of languages (which is something I don't think Exercism cares much about, but we do).

[joshgoebel]

@angelikatyborska Willing to whip up a PR based on your observations just to cleanup the keyword list (on top of the work in the PR that led us to this discussion)?

[angelikatyborska]

@joshgoebel Yes, I can help out with this issue. I can start today, but if I don't finish until the end of the day, it will probably wait until next weekend (UTC+2 time).

[joshgoebel]

There is no rush unless you're in a hurry. :) Looking forward to it whenever.