Add language: liquidsoap

[toots]

Description

This PR adds support for the liquidsoap language. The language has been existing since ~2005 and is widely used to run media streaming applications. Although its original scope is specialized, the language itself if a general-purpose scripting language that is functional and statically typed with inferred typed.

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:
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.liq
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • liquidsoap standard library: https://github.com/savonet/liquidsoap/tree/main/src/libs
    • Sample license(s): GPL 2.0 or later
  • I have included a syntax highlighting grammar: https://github.com/savonet/vscode-liquidsoap
  • I have added a color
    • Hex value: #990066
    • Rationale: Logo color. Logo has been used for probably 15 to 20 years.
  • I have updated the heuristics to distinguish my language from others using the same extension.
    • these extensions are unused by other languages at this time

[lildude]

Given its age, usage is surprisingly low in GitHub at the moment, but that could be due to old inactive repos that haven't been indexed yet (the new search will get to them one day).

Other than the suggestion, your three samples suppressed in the diff are too big (probably because of the extensive comments). Please replace these with smaller yet diverse samples with fewer comments.

As popularity isn't sufficient for inclusion right now, I'll label it as such and will review popularity with each release.

[toots]

Thanks for the review @lildude. I have applied the changes.

I am confused by the popularity assessment. I read the contribution guideline carefully before engaging in all the work required to implement the grammar and requirements for this so this comes as a surprise.

The contribution guidelines states that:

each new file extension [should] be in use in at least 200 unique :user/:repo repositories

Considering the poor results provided by the current search this was later amended in #5756, stating:

• at least 2000 files per extension indexed in the last year (the number you see at the top of the search results), unless the extension is expected to only occur once per repo, then 200 files.
• with a reasonable distribution across unique :user/:repo combinations assessed by manually and randomly clicking through the results.

In light of this, 1.7k files is already pretty close to the 2k threshold in and of it self. Furthermore, liquidsoap is a specialized programming language. Most of our users are not developers and most projects consists of one liquidsoap script file that defines all the streaming setup with e.g. a docker compose files or a CMS or database and website application, etc.

The search results only show 5 tabs with 20 entries each. That represents only the first 100 results, 5% of the total results. Glancing through these very limited results, however, it is clear that:

• Most repositories have between 1 and 5 files
• A lot of them are large projects with backend and front end for a radio-related website and only a handful of liquidsoap files

Considering this, I have no doubt that, should the search be returning satisfactory view on the actual data, it would show an even distribution of very well over 200 unique repositories. This is the assumption I made before starting this work.

We have engaged in this work because, on the user side, we have identified that, since most of our users are not developers, better support for tooling around the language is really important to improve understanding and learning it. This is part of a larger push that includes a tree-sitter grammar, a prettier plugin and vs-code extension (linked to this PR).

Support for the language in github would be a very valuable tool to help our users report issues and understand suggestions and responses to them, particularly since they are very new to programming.

The search results for issues reports about 3k of them mentioning the project and 1k pull requests. Discussions is a fairly new feature but it already almost 500 of them. A very quick google search on stackoverflow reveals at least 1k entries.

Our user community is very large, with over one million pull on the most popular docker image.

The project is used by multiple large scale organization (Radionomy, owner of winamp and shoutcast, live 365, Radio France with millions of daily listeners) as well as a great number of open source projects (AzuraCast, about 30k radio stations all running liquidsoap scripts, libretime, etc).

Lastly, but very importantly for us, multiple smaller community radios and communities around the world rely on the tool to communicate. See for instance some of the presentations during our 3rd liquidshop here: http://www.liquidsoap.info/liquidshop/3.

The project was also represented in the last two FOSDEM open-source conference at the media devrooms with solid interest from the audience.

Thus I would like to kindly ask if it would be possible to reconsider the popularity threshold in light of these details as I do believe that the language does meet the documented threshold for inclusion. Thank you for your consideration!