[Haskell-cafe] Re: Field names

[Mauricio]

>     abs (Pt {pointx = x, pointy = y}) = sqrt (x*x + y+y) 
> 
> 
> Why is it pointx=x and not x=pointx?
> 

Your intuition is probably telling you that this
is something like:

abs (point) = sqrt (x*x+y*y)
   where {x=pointx point ; y=pointy point}

Actually, it's an example of pattern matching:

abs (Pt {pointx=3 , pointy=4}) = 5
abs (Pt {pointx=3 , pointy=y}) = sqrt (9+y*y)
abs (Pt {pointx=z , pointy=z}) = (sqrt 2)*z

etc.

Best,
Maurício