Added Beluga language

[marcelgoh]

Adding support for Beluga, a functional programming language designed for reasoning about formal systems.

Description

Added grammar files, samples, and added Beluga to list of languages.

Checklist:

• I am adding a new language.
  • The extension of the new language is used in hundreds of repositories on github.com.
    • Search results for each extension:
      • .bel: ~500 results with keyword "rec"
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • jpath.bel: Link
    • Sample license(s):
      • jpath.bel: GPL 3.0
  • I have included a syntax highlighting grammar: Link to Lightshow
  • I have updated the heuristics to distinguish my language from others using the same extension.

[marcelgoh]

EDIT: I have fixed the problem. It appears I forgot to add Beluga to languages.yml. I apologise for the needlessly many commits.

After the original submission, I fixed as many issues as I could but the build still gets an error saying that no language was found for sample Beluga files I added. Would there be a simple fix for this?

[pchaigno]

I apologise for the needlessly many commits.

No worries. We're going to squash them at merge-time anyway.

Would there be a simple fix for this?

Yes, you need to add a real-world usage sample as per the contribution guidelines.

[marcelgoh]

I apologise for the needlessly many commits.

No worries. We're going to squash them at merge-time anyway.

Would there be a simple fix for this?

Yes, you need to add a real-world usage sample as per the contribution guidelines.

EDIT: I realise I forgot to add the samples to the actual pull request. I have updated the original checklist. Please do let me know of anything else I might be missing!

Hi! Thanks for considering my pull request! I think I managed to fix the problems I had earlier and the most recent commit seems to build.

[marcelgoh]

Would it be possible to add a colour for Beluga, as it is a programming language? What is the best way to choose a colour that doesn't conflict with others? I wasn't sure so I left it blank.

[pchaigno]

Using Harvester and the search query you provided, I counted only 12 repositories among 10 users. That is not enough to meet our usage requirement of hundreds of repositories.

How old is Beluga? Are there any reason to believe usage will increase exponentially in the next months?

[marcelgoh]

Using Harvester and the search query you provided, I counted only 12 repositories among 10 users. That is not enough to meet our usage requirement of hundreds of repositories.

How old is Beluga? Are there any reason to believe usage will increase exponentially in the next months?

Work on Beluga has been ongoing since 2009. While the current usage is not enormous, I believe that exposure for Beluga will only increase in the future, as more and more languages incorporate features that the creators of Beluga have been working on (e.g. dependent types, contexts). And because the .bel extension is not used by any other programming languages, I thought it would be a safe addition to GitHub's languages.

[pchaigno]

Okay. Let's reopen this pull request once usage is in the hundreds. Don't hesitate to ping me if you think we're there and would like me to run Harvester again.

And because the .bel extension is not used by any other programming languages, I thought it would be a safe addition to GitHub's languages.

That requirement stands for all extensions and languages, regardless of conflicts. If the extension was .beluga I might be less wary of adding it and would likely require less repositories than usual. But there's also a maintenance cost to any new extension and any new language, and we have to take that into account.

[marcelgoh]

Okay. Let's reopen this pull request once usage is in the hundreds. Don't hesitate to ping me if you think we're there and would like me to run Harvester again.

Sounds good. Thanks for the help!!