[Haskell-cafe] Re: Haskell as a first language?

[Ahn, Ki Yung]

Before teaching any data structure course, one MUST learn functional 
languages with ADTs.  It makes everything so easy to understand.  So, it 
MUST be a first language in every institution.

The biggest reason that one should learn functional languages with 
algebraic data type(ADT)s first is because understanding recursive 
definitions.  If you recursion first, understanding iteration and 
mutable data structures are dead simple and easy: they are just 
alternate representation or optimization.

However, when you learn while loops and for loops first, your brain gets 
damaged and a lot of students gets stuck when they first see the Tower 
of Hanoi, the notorious in-place quicksort routine written in imperative 
languages, you'll get to think of recursion as some stack blowing up 
monster that must be unrolled and managed manually.  Furthermore, 
learning data structures in most traditional imperative language 
literature gives you the impression that linked list and binary trees 
are brain-fucking spaghetti monsters of memory pointers all the cells, 
which is a dead simple recursive definition in functional languages with 
ADTs.

Personally, I never really understood what linked list was before I 
learned ML and Haskell, although I've used doubly linked list in a C++ 
standard library, which was to me a black box that meets the 
specification in some huge standard document, for two years.