On Fri, 22 Jun 2007, Dave Bayer wrote:
If I import a module that I don't use, then "ghc -Wall -Werror" rightly complains. By analogy, if I use "default (Int)" to ask GHC to default to Int but the situation never arises, then GHC should rightly complain. Instead, if I use "default (Int)", GHC complains about defaulting anyways. In my opinion, this is a bug, but I'd like guidance before reporting it. Is there a more elegant way to handle the numeric type classes with "ghc -Wall -Werror" ?
My understanding of defaulting is that it is bad style to rely on it. It is mostly needed for working in GHCi. For the particular exponentiation issue, I found the following: The overwhelming part of constant exponents of (^) in my modules is 2. The defaulting is mostly relevant for number literals, whereas variables get their types from somewhere else. So you may consider implementing a 'sqr' function for squaring values.