Add OMNeT++ MSG language

[adamgeorge309]

This adds the OMNeT++ MSG language.

Description

MSG (extension .msg) is a DSL for the OMNeT++ network simulator. It is used by model frameworks for OMNeT++, such as the INET framework, Simu5G, Veins, etc. We are the team that develops OMNeT++ and the INET Framework and we have created a TextMate grammar for this language.

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*.msg+opensim
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/inet-framework/inet
    • Sample license:
      • LGPLv3
  • I have included a syntax highlighting grammar: https://github.com/omnetpp/omnetpp-textmate-msg
  • I have added a color
    • Hex value: #a0e0a0
    • Rationale: Matches the branding guidelines for the OMNeT++ project.
  • I have updated the heuristics to distinguish my language from others using the same extension.

[lildude]

This is a very generic extension which matches way more files than your limited search which means they'll all be identified as this language.

As such, you'll need to add this extension to the generic.yml and add a very precise heuristic that only matches files for this language.

[adamgeorge309]

I did the heuristics. Thanks.

[adamgeorge309]

Based on the heuristic, I refined the popularity search:

https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.msg+content%3A%2F%5Ecplusplus+%5C%7B%5C%7B%7C%5Enamespace%5B%5Cs%5D*%28%5B%5E.%5Cs%5D*%5C.%29*%5B%5E.%5Cs%5D*%3B%7C%5Estruct+%5C%7B%7C%5Emessage+%5B%5CS%5D*+%28extends%29%3F+%5B%5CS%5D*%5B%5Cs%5D*%5C%7B%7C%5Epacket+%5C%7B%7C%5Eclass+%28extends%29+%5B%5CS%5D*%5B%5Cs%5D*%5C%7B%7C%5Eenum+%5C%7B%7C%5Eimport+%28%5B%5E.%5Cs%5D*%5C.%29*%5B%5E.%5Cs%5D*%3B%2F

This should be a more accurate search for assessing the popularity. Thank you!

[lildude]

Please merge main into your branch so CI can run. I'd normally do it but as your PR comes from an org-owned fork, permission can't be granted to me.

[lildude]

These are legit failures:

  1) Failure:
TestPedantic#test_heuristics_tests_are_exhaustive [test/test_pedantic.rb:62]:
Extension .msg has no test in test_heuristics.rb

We need a test for this heuristic.

[lildude]

Please remove samples/omnetpp-msg/Ieee80211Frame.msg as it's too large and unnecessary as there three other files.

[lildude]

Lovely! Thanks for addressing those issues. 🙇

[adamgeorge309]

Thanks