adding vhdl language

[a-rey]

Hello!

I use some hardware description languages in a website of mine and was sad to see they are not supported by Prism. Here is my proposed Prism support for the VHDL language. Let me know if there are any issues!

sample code below borrowed from here

[Golmote]

Why not .+ instead of [^\r\n]+? And there is no need for the parentheses.

[Golmote]

Thanks for contributing!

Please take a look at my comments ;)

[a-rey]

Thank you for your comments!

I made the changes you brought up. Let me know if you see anything else.

[LeaVerou]

I left the [01uxzwlh-] part in the number pattern and not in the vhdl-vectors pattern to avoid the issue of a '0' inside of a string (example: "blah blah '1' blah") being highlighted before strings had their chance.

Not sure what you mean here exactly, but strings are processed before numbers, since the string token comes earlier in your definition.

[Golmote]

Alright, this makes sense. Since vhdl-vectors are processed before strings, he wanted to prevent those single-quoted numbers from breaking the highlighting of strings.

[Golmote]

No need for the enclosing parentheses here.

[Golmote]

I added a couple of comments. Apart from them, this looks good to me.

[a-rey]

Made the requested changes. Thanks again!

[LeaVerou]

LGTM! Please add a minified version? Also, examples in the examples page would be nice, but not required.

Thanks for the contribution!!

[Golmote]

If needed, I can merge, build the minified version and add the example given in the first message of this PR, when I get back from work.

[a-rey]

minified and example ready!

[Golmote]

This looks great, thanks. As it looks good to @LeaVerou too, I'll merge now.