splitAtTopLevelOnly.js
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/**
* This splits a string on a top-level character.
*
* Regex doesn't support recursion (at least not the JS-flavored version).
* So we have to use a tiny state machine to keep track of paren placement.
*
* Expected behavior using commas:
* var(--a, 0 0 1px rgb(0, 0, 0)), 0 0 1px rgb(0, 0, 0)
* ─┬─ ┬ ┬ ┬
* x x x ╰──────── Split because top-level
* ╰──────────────┴──┴───────────── Ignored b/c inside >= 1 levels of parens
*
* @param {string} input
* @param {string} separator
*/ "use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
Object.defineProperty(exports, "splitAtTopLevelOnly", {
enumerable: true,
get: ()=>splitAtTopLevelOnly
});
function splitAtTopLevelOnly(input, separator) {
let stack = [];
let parts = [];
let lastPos = 0;
for(let idx = 0; idx < input.length; idx++){
let char = input[idx];
if (stack.length === 0 && char === separator[0]) {
if (separator.length === 1 || input.slice(idx, idx + separator.length) === separator) {
parts.push(input.slice(lastPos, idx));
lastPos = idx + separator.length;
}
}
if (char === "(" || char === "[" || char === "{") {
stack.push(char);
} else if (char === ")" && stack[stack.length - 1] === "(" || char === "]" && stack[stack.length - 1] === "[" || char === "}" && stack[stack.length - 1] === "{") {
stack.pop();
}
}
parts.push(input.slice(lastPos));
return parts;
}