Feature request: Pass array/Regexp to namespace/request methods

[elado]

Currently, if I have 2 endpoints I want to merge into one, all I can do is to loop and create requests:

%w(a b c).each do |key|
  namespace key do
    get do
      "hello #{key}"
    end
  end
end

%w(e f g).each do |key|
  namespace key do
    get do
      "hello again #{key}"
    end
  end
end

In the case above, I can't use named namespace (namespace ":key") because it'll take over both request groups.

A nicer way would be to be able to send an array or regexp to namespace or get:

namespace %w(a b c) do
  get do
    "hello"
  end
end

namespace %r[^(?<key>e|f|g)$] do # regexp to support named groups
  get do
    "hello #{params[:key]}"
  end
end

get %r[^(?<key>h|i|j)$] do
  "hello #{params[:key]}"
end

Kind of aliasing same requests to a single block (also saves memory) for API changes, backward compatibility etc.

[dblock]

I am not opposed to namespace (and other keywords) to take arrays of things to start. I think the regex might be a stretch though.

It would probably also help if you could mount the same API under different namespaces, which is discussed in #570