'use strict'; module.exports = balanced; function balanced(a, b, str) {

if (a instanceof RegExp) a = maybeMatch(a, str);
if (b instanceof RegExp) b = maybeMatch(b, str);

var r = range(a, b, str);

return r && {
  start: r[0],
  end: r[1],
  pre: str.slice(0, r[0]),
  body: str.slice(r[0] + a.length, r[1]),
  post: str.slice(r[1] + b.length)
};

}

function maybeMatch(reg, str) {

var m = str.match(reg);
return m ? m[0] : null;

}

balanced.range = range; function range(a, b, str) {

var begs, beg, left, right, result;
var ai = str.indexOf(a);
var bi = str.indexOf(b, ai + 1);
var i = ai;

if (ai >= 0 && bi > 0) {
  begs = [];
  left = str.length;

  while (i >= 0 && !result) {
    if (i == ai) {
      begs.push(i);
      ai = str.indexOf(a, i + 1);
    } else if (begs.length == 1) {
      result = [ begs.pop(), bi ];
    } else {
      beg = begs.pop();
      if (beg < left) {
        left = beg;
        right = bi;
      }

      bi = str.indexOf(b, i + 1);
    }

    i = ai < bi && ai >= 0 ? ai : bi;
  }

  if (begs.length) {
    result = [ left, right ];
  }
}

return result;

}