Regex match all excluding a delimiter

Question

I have two sample strings of code like so:

"const x = anything;"
"const {a, b, c, d} = anything;"

I want to match x, as well as a, b, c, and d (none of which are literal, they can be any valid JavaScript variable character(s), but are delimited by commas) if they are preceded by the keyword const. The latter is the destructuring syntax.

Context: this is to extend syntax highlighting of code tokens in PrismJS.

What I've tried so far:

  Prism.languages.insertBefore(lang, 'operator', {
    constant: {
      pattern: /(const\s?{?)[\s_$a-zA-Z\xA0-\uFFFF,]*(?!:)/,
      lookbehind: true,
    },
  });

The comma is inside the [], and I am not sure of how to "continue" matching each variable inside the braces without including the comma character.

The goal is to not color `var` and `let` variables, only `const` ones, for semantic reasons. — frosty, Dec 04 '21 at 12:08
Maybe [`/(?<=const\s+)[$\w]+|(?<=const\s*{[^{}]*)[$\w]+/g`](https://regex101.com/r/3Zfrsb/1)? Not sure it will work in Prism though. — Wiktor Stribiżew, Dec 04 '21 at 12:17
@WiktorStribiżew `$\w` is too restrictive for [variable names](https://stackoverflow.com/questions/1661197/what-characters-are-valid-for-javascript-variable-names). — Roko C. Buljan, Dec 04 '21 at 12:22
@RokoC.Buljan I only cared to create a PoC pattern, enhancing is always the last step. If that expression works, the rest is just a matter of adding the finishing touch. It is not an answer. — Wiktor Stribiżew, Dec 04 '21 at 12:45

Inigo · Answer 1 · 2021-12-04T15:35:48.983

0

Try this pattern:

(?:const\s+{?\s*)[_$\w]+(?:[,}\s])

I'll try and improve it by replacing \w to match identifiers using non-alphanumeric characters. Possibly:

(?:const\s+{?\s*)[_$\p{L}]+(?:[,}\s])

edited Dec 04 '21 at 15:35

answered Dec 04 '21 at 15:22

Inigo

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Regex match all excluding a delimiter

1 Answers1