Add URScript language

[EbbeFuglsang]

URScript is the custom programming language, developed by Universal Robots, that controls the robot arm. Any interactions with PolyScope get converted into URScript commands, and are subsequently sent to the robot to be executed. This high level language is easy to learn, and allows you to program the robot without the PolyScope graphical interface. The URScript Manual contains an overview of the language structure, information on data types, and a complete reference of the standard functions.

Description

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?utf8=%E2%9C%93&q=urscript&type=repositories&ref=searchresults
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.script+URScript
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • [URL to each sample source, if applicable]
    • Sample license(s): https://github.com/UniversalRobots/URScript_Examples/tree/main/admittance-control BSD 3-Clause License
  • I have included a syntax highlighting grammar: [URL to grammar repo]
  • I have added a color
    • Hex value: #RRGGBB
    • Rationale: This is Universal Robots brand color
  • I have updated the heuristics to distinguish my language from others using the same extension.

[lildude]

In addition to the inline comments, you're also going to need to add this to generic.yml and come up with a 100% precise matching regex and add it to the heuristics. This is because .script is incredibly generic so the only way we'll be able to correctly identify these files is via a heuristc.

Popularity is no where near ready for merging so you might want to consider holding off on the suggested changes, close this PR and wait for popularity to meet our requirements.

[EbbeFuglsang]

Regarding popularity this search:
urscript OR UR5 AND ROS OR URCap gives 1.6k repos. They might not all have the URScript in seperate file. But with this search:
https://github.com/search?type=code&q=%28urscript+AND+path%3A*.script%29+OR+%28UR5+AND+ROS+AND+path%3A*.script%29+OR+%28URCap+AND+path%3A*.script%29+ gives 542 different .script files that holds URScript.
What is the threshold?

Regarding the heuristc. That makes a lot of sense. I will look into that. Thank you for you feedback so far🙏

[lildude]

What is the threshold?

linguist/CONTRIBUTING.md

Lines 76 to 80 in 5fad8d5

	## Adding an extension to a language
	We try only to add new extensions once they have some usage on GitHub.
	In most cases we prefer that each new file extension be in use in at least 200 unique `:user/:repo` repositories before supporting them in Linguist
	(but see [#5756][] for a temporary change in the criteria).

[EbbeFuglsang]

I just added some heuristics I think that should reduce the risk of false positives.

[lildude]

Please merge main into your branch. Your branch is still showing signs of #7145 which has been resolved now.

[lildude]

See inline comments.

[lildude]

This looks much better, thanks. I think there's still room for improvement:

Suggested change

	pattern: '^\s*def\s*[a-zA-Z_][a-zA-Z0-9_]*\s*\([^)]*\)\s*:[\s\S]*\send($|\s)'
	pattern: '^\s*def\s+[a-zA-Z_]\w*\s*\([^)]*\)\s*:[\s\S]*\send\b'

• ^\s*def\s* replaced with ^\s*def\s+ as it appears at least one space is required
• [a-zA-Z0-9_]* is the same as \w*
• \s*end($|\s) is simplified to \s*end\b as \b matches a word boundary, which is equivalent to the end of the word end.

@Alhadis may have some further suggestions.

[Alhadis]

1. \send\b will match a (presumably illegal) construction like end., end-, end(, and many, many others.

2. For performance's sake, [\s\S]* should match conservatively ([\s\S]*?) so that anything past the first \send\b isn't searched and included as part of the match:

   #!/usr/bin/env ruby
   greedy  = /^\s*def\s*[a-zA-Z_][a-zA-Z0-9_]*\s*\([^)]*\)\s*:[\s\S]*\send($|\s)/
   thrifty = /^\s*def\s*[a-zA-Z_][a-zA-Z0-9_]*\s*\([^)]*\)\s*:[\s\S]*?\send($|\s)/
   input   = File.read("samples/URScript/admittance_control.script")
   
   greedy  =~ input; $&.length # => 10019
   thrifty =~ input; $&.length # => 126

[lildude]

This is unnecessary (\s* is zero or more which includes \s+ which is one or more) and introduces a ReDoS.

[EbbeFuglsang]

I see. I reverted the commit.