[erlang-questions] lists:seq/3 strange behaviour

Bartłomiej Puzoń <>
Tue Jun 15 14:04:24 CEST 2010

This behaviour is actually described in lists manual:

"Failure: If To<From-Incr and Incr  is positive,
  or if To>From-Incr and Incr is negative, 
  or if Incr==0 and From/=To."

If you drop this assumptions, their algorithm for lists:seq (meant to be fast?) may not stop 
(according to the lists source code).

----- "Piotr Kaleta" <> escribió:

> What was the reason for lists:seq function to be implemented in a way
> that if you call:
> lists:seq(2, 1, 10)
> it works as expected returning an an empty list, while when beeing 
> called like:
> lists:seq(20, 1, 10)
> it throws an exception?
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Bartłomiej Puzoń
Erlang Solutions




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