Parallel list comprehensions

[Ross Paterson]

On Thu, Feb 16, 2006 at 01:27:52AM -0800, John Meacham wrote:
> I would be worried about dropping things because people exist
> who have not used the feature. For all they know, they might love it
> once they start using it. Very little of haskell is manditory so there
> really is no need for everyone to explore every corner of the language,
> but a lot of the syntax makes our lives easier, sometimes substantially
> so.

Features do impact on people who never use them: when they make errors
that stray near the syntactic and type-system space occupied by the
feature, and when they read or modify code written by others.  As JohnH
said, every addition increases the cost of the language, and needs to
bring significant benefit to justify inclusion.

> Oh golly. I can't live without pattern guards.

Yes, I knew my position was more extreme there.