A small refactor story

I was working on AREL expression chaining and stumbled on an opportunity to use reduce/inject.

This is easy to understand, but verbose, and suffers from treating the first value in a special way:

combo = expression_proc.call(values.first)

values[1..].each { combo = combo.and(expression_proc.call(_1)) }

combo

This starts using reduce, but trades clarity for terseness, a downgrade:

combo = expression_proc.call(values.first)

values[1..].reduce(combo) do |mem, clause|
  mem.and(expression_proc.call(clause))
end

Let's transform all values to expression objects to start.
reduce really could be aliased to chain_with. :)

clean_value.map { expression_proc.call(_1) }.reduce(:and)