From: Joel VanderWerf <joelvanderwerf@...>
Date: 2010-07-07T01:52:32+09:00
Subject: Re: WTF? Case statement disfunctional?

Caleb Clausen wrote:
> Don't think of === as a 'more forgiving' ==. It doesn't provide a
> superset of =='s behavior; it's more like a better equality operator
> for use in case expressions. === actually has rather complicated
> semantics which depend on the type of its left-side argument, so it's
> hard to come up with a pithy one-line description.

I think of "pattern === val" as a general pattern matching predicate, 
which makes the asymmetry more palatable. It's kind of unfortunate that 
the "===" string itself is symmetrical.