54 lines
1.6 KiB
JavaScript
54 lines
1.6 KiB
JavaScript
export const balanced = (a, b, str) => {
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const ma = a instanceof RegExp ? maybeMatch(a, str) : a;
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const mb = b instanceof RegExp ? maybeMatch(b, str) : b;
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const r = ma !== null && mb != null && range(ma, mb, str);
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return (r && {
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start: r[0],
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end: r[1],
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pre: str.slice(0, r[0]),
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body: str.slice(r[0] + ma.length, r[1]),
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post: str.slice(r[1] + mb.length),
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});
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};
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const maybeMatch = (reg, str) => {
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const m = str.match(reg);
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return m ? m[0] : null;
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};
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export const range = (a, b, str) => {
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let begs, beg, left, right = undefined, result;
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let ai = str.indexOf(a);
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let bi = str.indexOf(b, ai + 1);
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let i = ai;
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if (ai >= 0 && bi > 0) {
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if (a === b) {
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return [ai, bi];
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}
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begs = [];
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left = str.length;
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while (i >= 0 && !result) {
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if (i === ai) {
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begs.push(i);
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ai = str.indexOf(a, i + 1);
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}
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else if (begs.length === 1) {
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const r = begs.pop();
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if (r !== undefined)
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result = [r, bi];
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}
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else {
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beg = begs.pop();
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if (beg !== undefined && beg < left) {
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left = beg;
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right = bi;
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}
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bi = str.indexOf(b, i + 1);
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}
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i = ai < bi && ai >= 0 ? ai : bi;
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}
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if (begs.length && right !== undefined) {
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result = [left, right];
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}
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}
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return result;
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};
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//# sourceMappingURL=index.js.map
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