[Haskell-cafe] Why?

[Magnus Therning]

On Thu, Dec 10, 2009 at 12:01 PM, John D. Earle <JohnDEarle at cox.net> wrote:
> This is a matter that I genuinely at the present time do not grasp and I am
> hoping that some of you who are more familiar with the Haskell language may
> be able to help enlighten me. I feel the question to be an important one.
> What material benefit does Haskell derive from being a "pure" functional
> language as opposed to an impure one? Please provide examples as I require
> instruction.
>
> The following is what I believe to be true at the present time. It seems to
> be that the decision was made because it was a matter of taste under the
> belief that computer scientists can and often are superstitious and their
> superstitions can and often do materially interfere with progress. What I am
> saying is that at the present time perhaps due to my ignorance I am
> unfamiliar with how this benefits the language in a material sense. It
> appears to be a philosophical matter, a matter of identity, what Haskell
> stands for.
>
> The sort of decision that Apple computer and Microsoft made not to go down
> the POSIX road seems relevant. Historically, Apple did not embrace POSIX.
> Windows continues to stand for Windows, that is the graphical user
> interface.

As I understand it it all started with laziness.  I don't know if
laziness is impossible without purity, but talks and papers tend to
say something like "laziness has kept Haskell pure".

/M

-- 
Magnus Therning                        (OpenPGP: 0xAB4DFBA4)
magnus＠therning．org          Jabber: magnus＠therning．org
http://therning.org/magnus         identi.ca|twitter: magthe