#injecting on Enumerable

injecting makes inject easier to use. Rather than returning the accumulator from your block, the accumulator is modified in place.

Apparently Merb had this method for a while, but lost it in the rewrite. I've adapted it to Rails in an idiomatic style.

For example:

%w(foo bar).injecting({}) { |hsh, str| hsh[str] = str.upcase } # => {'foo' => 'FOO', 'bar' => 'BAR'}