Numeric instances for Convertible.
Copyright (C) 2009-2011 John Goerzen email@example.com
All rights reserved.
For license and copyright information, see the file LICENSE
These instances perform conversion between numeric types such as
Double, Int, Integer, Rational, and the like. Here are some notes
about the conversion process:
Conversions from floating-point types such as Double to integral types
are done via the truncate
function. This is a somewhat
arbitrary decision; if you need different behavior, you will have to
write your own instance or manually perform the conversion.
All conversions perform bounds checking. If a value is too large for
its destination type, you will get a ConvertError
of this. Note that this behavior differs from functions in the Haskell
standard libraries, which will perform the conversion without error,
but give you garbage in the end.
Conversions do not perform precision checking; loss of precision is
implied with certain conversions (for instance, Double to Float) and
this is not an error.