Extending a sig

snippet.js

// NB: all three of these will have the same comment documentation

var minimumSig = function(start, mid, end) = {
  var newMid;
  if (arguments === 3) {
    newMid = mid;
  } else if (arguments === 4) {
    newMid = arguments[2];
    end = arguments[3];
  } else {
    // should I do something here?
  }

  doTheThing(start, mid, newMid, end);
}

var maximalSig = function(start, mid, newMid, end) = {
  if (arguments === 3) {
    newMid = mid;
    end = arguments[2]; // because it's currently bound to newMid with end being undefined
  } else {
    // should I do something here?
  }

  doTheThing(start, mid, newMid, end);
}

var noSig = function() {
  var start, mid, newMid, end;

  start = arguments[0];
  mid = arguments[1];
  if (arguments === 3) {
    newMid = mid;
    end = arguments[2];
  } else if (arguments === 4) {
    newMid = arguments[2];
    end = arguments[3];
  }
}