On 11 Feb 2008, at 7:52 AM, Arnar Birgisson wrote:
Hi all,
On Feb 11, 2008 3:14 PM, apfelmus <[EMAIL PROTECTED]> wrote:
I will be mean by asking the following counter question:
x + (y + z) = (x + y) + z
is a mathematical identity. If it is a mathematical identity, a
programmer need not care about this law to implement addition + . Can
anyone give me an example implementation of addition that violates
this law?
Depends on what you mean by "addition". In general, algebraists call
any associative and commutative operation on a set "addition", and
nothing else. From that POV, there is by definition no "addition" that
violates this law.
I agree. The Num Double instance should be expelled from the Prelude
immediately.
jcc
(What? Haskell has a Float type?)
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