[eru]

>> Write software faster with fewer bugs > Is there an evidentiary basis for the 'fewer bugs' claim? What type of software are people writing faster with Haskell?

http://donsbot.wordpress.com/2007/05/01/roll-your-own-window... and especially http://donsbot.wordpress.com/2007/05/17/roll-your-own-window... give a good introduction into the mindset behind programming in Haskell.

The latter focusses on zippers. Zippers solve the problem of having a connection and a `cursor' into that connection to mark one element--in the case of XMonad we mark the window that has focus.

In C you would probably solve this with an array and an int. Unfortunately, the compiler can't help ensure that your int always points into the array, and that deleting and inserting are doing the right thing. Zippers help here.