javascript braces validation, with use array and object as dictionary

braces_valid.js

// ========== array brace validation

const edict_arr = [
  ['[', ']'],
  ['(', ')'],
  ['{', '}'],
];


function valid_arr(braces){
  const chars = braces.split('');
  const stuck = [];
  for(let i = 0; i < chars.length; ++i) {
    for(let e = 0; e < edict_arr.length; ++e) {
      if(chars[i] === edict_arr[e][0]){
        stuck.push(chars[i]);
      } else if(chars[i] === edict_arr[e][1]) {
        const prev = stuck.pop();
        if(edict_arr[e][0] !== prev){
          return false;
        }
      }
    }
  }

  if(stuck.length > 0) return false;

  return true;
}

// ========== map bracke validation

const edict_map = {
  '[':']',
  '(':')',
  '{':'}',
};

function revert_object(obj){
  const res = Object.create(null);
  for(e in obj) res[obj[e]] = e;
  return res;
}

const edict_map_revert = revert_object(edict_map);

function valid_map(braces){
  const chars = braces.split('');
  const stuck = [];
  for(let i = 0; i < chars.length; ++i) {
    if(edict_map[chars[i]] !== undefined){
      stuck.push(chars[i]);
    } else {
      // check proper symbols
      if(edict_map_revert[chars[i]] === undefined) {
        continue;
      }
      const prev = stuck.pop();
      if(chars[i] !== edict_map[prev]){
        return false;
      }
    }
  }

  if(stuck.length > 0) return false;

  return true;
}

console.assert(valid_map("()")===true);
console.assert(valid_map("(){}[]")===true);
console.assert(valid_map("([{rrr}])")===true);
console.assert(valid_map("[(])")===false);
console.assert(valid_map("(}")===false);
console.assert(valid_map("[(])")===false);
console.assert(valid_map("[({eee})](]")===false);

console.assert(valid_arr("()")===true);
console.assert(valid_arr("(){}[]")===true);
console.assert(valid_arr("([{rrr}])")===true);
console.assert(valid_arr("[(])")===false);
console.assert(valid_arr("(}")===false);
console.assert(valid_arr("[(])")===false);
console.assert(valid_arr("[({eee})](]")===false);