Interpolated string?

[RedCMD]

what goes inside the escaped brackets?

is it just source.pkl code?
couldn't you use a begin/end so that it can handle nested code 100% correctly?
and should use scope meta.embedded to enable bracket pair highlighting

pkl.tmbundle/Syntaxes/pkl.tmLanguage

Line 1387 in 3a2e984

.+? # one or more characters lazily (correct syntax highlighting within here should be provided by semantic tokens)

[RedCMD]

should move to https://github.com/apple/pkl.tmbundle

[bioball]

Transferred!

[bioball]

Yeah, it should be source.pkl within interpolation.

A begin/end pattern sounds like a better way to handle this.