| John Peterson writes
|
| Int is really not a nice
| datatype and we shouldn't be allowing it to crop up unexpectedly.
|
| Yes, but if we believed that, we should use Integer, not Int, for
| length.
|
| You are right, beginners may stub their toe on factorial. On the other
| hand, with the default set to Integer, beginners may stub their toe
| on bad performance. Anyone familiar with, say, C, will be unsurprised
| by the need to switch Int to Integer to get factorial to work, but will
| be very surprised by the need to switch Integer to Int to get decent
| performance. -- P
I'd like to support John P. and Colin R. on this point. The very
Haskell beginner enters the Hugs interpreter and types (motivated by
his instructor)
Prelude> product [1..100]
0
Ops, the instructor forgot that the default default is Int. Beginners
who already worry about performance (by a constant factor) should have
no problem in adding a default declaration.
Having Integer as the default default has also the beneficial side-effect
to motivate implementors to improve upon the status quo ;-).
Cheers, Ralf
