opusdev/vector-similarity-api

1'use strict';2module.exports = balanced;3function balanced(a, b, str) {4  if (a instanceof RegExp) a = maybeMatch(a, str);5  if (b instanceof RegExp) b = maybeMatch(b, str);6 7  var r = range(a, b, str);8 9  return r && {10    start: r[0],11    end: r[1],12    pre: str.slice(0, r[0]),13    body: str.slice(r[0] + a.length, r[1]),14    post: str.slice(r[1] + b.length)15  };16}17 18function maybeMatch(reg, str) {19  var m = str.match(reg);20  return m ? m[0] : null;21}22 23balanced.range = range;24function range(a, b, str) {25  var begs, beg, left, right, result;26  var ai = str.indexOf(a);27  var bi = str.indexOf(b, ai + 1);28  var i = ai;29 30  if (ai >= 0 && bi > 0) {31    if(a===b) {32      return [ai, bi];33    }34    begs = [];35    left = str.length;36 37    while (i >= 0 && !result) {38      if (i == ai) {39        begs.push(i);40        ai = str.indexOf(a, i + 1);41      } else if (begs.length == 1) {42        result = [ begs.pop(), bi ];43      } else {44        beg = begs.pop();45        if (beg < left) {46          left = beg;47          right = bi;48        }49 50        bi = str.indexOf(b, i + 1);51      }52 53      i = ai < bi && ai >= 0 ? ai : bi;54    }55 56    if (begs.length) {57      result = [ left, right ];58    }59  }60 61  return result;62}63