Hi.

[Changed the first line into a block, threw in a pair of parenthesis]

> = aRenameVariableChange
> ^([self class = aRenameVariableChange class],
> [className = aRenameVariableChange changeClassName],
> [isMeta = aRenameVariableChange isMeta],
> [oldName = aRenameVariableChange oldName],
> [newName = aRenameVariableChange newName]) allTrue

Unary selector?  No kidding!  It just reads "I am equal to xyz if all
these things are true"!  This is great!!!

> The resulting pattern is not bad, but the implementation creeps me out a
> bit... adding messages and subclasses to Boolean and BlockContext is a
> bit extreme for my taste...

Making it very simple, and just supporting what we want lets us see
that:

* We don't need single blocks to be polymorphic with booleans.
* We don't need BlockContextComposites to understand ifTrue: ifFalse:
etc, just allTrue, allFalse, etc.

So, let's just

1. Add #, to BlockContext.
2. Object subclass: BooleanCondition.

There's something extra, a particular approach that would deliver an
even smaller implementation.  We can cascade the queries to the
condition, so there's no need to implement ifAllTrue:ifAllFalse:,
ifAnyTrue:ifAnyFalse: neither the more logically complete
ifAllTrue:ifAnyTrue:ifAllFalse:, plus all its combinations, negations
and permutations.

Here's the tiny tiny implementation, with tests.  It just came out so
beautifully!

Andres.
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