src/node_modules/clean-css/lib/optimizer/level-2/specificities-overlap.js

var specificity = require('./specificity');

function specificitiesOverlap(selector1, selector2, cache) {
  var specificity1;
  var specificity2;
  var i, l;
  var j, m;

  for (i = 0, l = selector1.length; i < l; i++) {
    specificity1 = findSpecificity(selector1[i][1], cache);

    for (j = 0, m = selector2.length; j < m; j++) {
      specificity2 = findSpecificity(selector2[j][1], cache);

      if (specificity1[0] === specificity2[0]
        && specificity1[1] === specificity2[1]
        && specificity1[2] === specificity2[2]) {
        return true;
      }
    }
  }

  return false;
}

function findSpecificity(selector, cache) {
  var value;

  if (!(selector in cache)) {
    cache[selector] = value = specificity(selector);
  }

  return value || cache[selector];
}

module.exports = specificitiesOverlap;