Add coercion for Array and Hash to Virtus::Coercion::Object

[solnic]

Add coercion for Array and Hash to Virtus::Coercion::Object

[solnic]

Yes, I like that. We should also think about making sure that coercions are 'symmetrical' - we've discussed this once I believe.

[dkubb]

@solnic sure, where it's possible. I believe we could make a method that coerces an Array into a Hash by passing it into Hash[], for example. I think we already have stuff to coerce Hash into an Array.

The general idea is that if Ruby provides conventions for conversions into specific primitives, then I want to use those methods by default if they're available. Coercion subclasses can override that if there's a more idiomatic way to convert to the primitive.

[dkubb]

Ok, I added #to_hash, #to_string and #to_integer to Virtus::Coercion::Object. Marking this issue as closed.

I decided to only use the explicit coercion methods (#to_hash, #to_str, and #to_int respectively) because the other methods are used in a bit "fast and loose" style within ruby core/stlib.

Also nearly every object responds to #to_s, and we don't want to coerce stuff into strings and end up with the inspect output -- with virtus' coercions we're looking for cases where the coercion is explicit and in many cases can be reversed because there was no loss of information.