On: It's Coming: The Great Swift API Transformation

[nardi]

The point here (no pun intended) is to stop repeating noun phrases at the call site. Your call site says "point" twice for no reason:

    path.addLine(toPoint: CGPoint(x: 100, y: 0))

See the "toPoint: CGPoint". It's useless repetition. The new form eliminates it:

    path.addLineTo(CGPoint(x: 100, y: 0))

It's clear you're adding a line to a point, because it says "Point" right there. Even if you have a variable for this point already, it works great:

    path.addLineTo(point)

Or maybe this is a more specifically named point?

    path.addLineTo(centerPoint)

It's clear from all that you're adding a line to a point. Swift has an emphasis on concise syntax, and removing the repetition, IMO, is a nice win in readability.

[ceeK → nardi]

You do have a good point, and something I didn't explicitly notice before. This does seem to have the indirect consequence of enforcing some sort of type information in the variable name, but I expect many iOS developers do that regardless.

It'd also be interesting to see the impact on readability when you have longer variable names. `point` definitely makes it more concise here. But if you had several points within the same scope, readability may suffer given type information is typically at the end of a variable name?

  path.addLineTo(childViewTopLeftPoint)
  path.addCurveTo(childViewTopRightPoint, withControlPoint1: arbitrary1Point, andControlPoint2: arbitrary2Point)

  path.addLine(toPoint: childViewTopLeftPoint)
  path.addCurve(toPoint: childViewTopRightPoint, withControlPoint1: arbitrary1Point, andControlPoint2: arbitrary2Point)

I feel the second version here allows me to bypass obtaining the type information "..Point" from the variable name when reading.

Interestingly, I wonder how this type of method would be converted:

  addArcWithCenter(center: CGPoint, radius: CGFloat, startAngle: CGFloat, endAngle: CGFloat, clockwise: Bool)

You'd perhaps think of addArcWith(center: CGPoint), but then you'd need to have 'center' in the variable name to convey meaning. Keeping addArcWithCenter maintains obj-c status quo. addArc(withCenter: CGPoint) is more Swifty, but you may have repetition if your variable is named centerPoint, or similar. I have a feeling it would be kept as is.