is identity the only polymorphic function without typeclasses?

Andrew J Bromage
Mon, 3 Mar 2003 10:33:47 +1100

G'day all.

On Sun, Mar 02, 2003 at 10:18:13AM +0200, Cagdas Ozgenc wrote:

> Is identity function the only meaningful function one can write
> without constraining the type variable using a typeclass? If not,
> could you please give a counter-example?

This might help:

@incollection{ wadler89theorems,
    author = "Philip Wadler",
    title = "Theorems for Free!",
    booktitle = "Proceedings 4th Int.\ Conf.\ on Funct.\ Prog.\ Languages and Computer Arch., {FPCA}'89, London, {UK}, 11--13 Sept 1989",
    publisher = "ACM Press",
    address = "New York",
    pages = "347--359",
    year = "1989"

Andrew Bromage