Support special escape sequences in Terraform

[tancnle]

This MR adds support for special escape sequences $${ and %%{ in Terraform lexer.

https://developer.hashicorp.com/terraform/language/expressions/strings#string-templates

Before	After

Fixes #2061

[tancnle]

👋🏼 @Sayrus could you kindly help to confirm if this addresses #2061?

[Sayrus]

👋🏼 @Sayrus could you kindly help to confirm if this addresses #2061?

Hey @tancnle , thanks for taking time to look into this issue !

While not having an error is a huge improvement, I think the entire string should be colored as a string. Since $${ is a string literal, local.demo is not interpolated so the entire thing is a normal string.

I'm not sure we want to highlight $${ in any special way, maybe we'd like to match other escape sequences such as \n.

[tancnle]

Thanks, @Sayrus. That makes sense. Would something like the attached screenshot look better?

[Sayrus]

Thanks, @Sayrus. That makes sense. Would something like the attached screenshot look better?

Looks good to me!