On Mon, Jul 7, 2008 at 2:21 PM, Michael Feathers
Thanks. Here's a newb question: what does strictness really get me in this code?
A bit of speed and memory improvements, I suspect. The type (Double,Double) has three boxes, one for the tuple and one for each double. The type Complex, which is defined as data Complex a = !a :+ !a has one box (after -funbox-strict-fields has done its work), the one for the type as a whole. So it will end up using less memory, and there will be fewer jumps to evaluate one (a jump is made for each box).
BTW, I only noticed the Complex type late. I looked at it and noticed that all I'd be using is the constructor and add. Didn't seem worth the change.
You would also be using the multiply and magnitude functions! And you would gain code readability, since you could define: mandel c z = z^2 + c trajectory c = iterate (mandel c) 0 Which is basically the mathematical definition right there in front of you, instead of splayed out all over the place. Luke