code: function checkBlockdecl(i) {
    let l;
  
    if (i >= tokensLength) return 0;
  
    if (l = checkBlockdecl7(i)) tokens[i].bd_type = 7;
    else if (l = checkBlockdecl5(i)) tokens[i].bd_type = 5;
    else if (l = checkBlockdecl6(i)) tokens[i].bd_type = 6;
    else if (l = checkBlockdecl1(i)) tokens[i].bd_type = 1;
    else if (l = checkBlockdecl2(i)) tokens[i].bd_type = 2;
    else if (l = checkBlockdecl3(i)) tokens[i].bd_type = 3;
    else if (l = checkBlockdecl4(i)) tokens[i].bd_type = 4;
    else return 0;
  
    return l;
  }
docs: Checks if token is part of a declaration (property-value pair).
  
  @param {number} i Token's index number
  @return {number} Length of the declaration