protobuf/upb/bindings/ruby

Ruby extension

To build, run (from the top upb directory):

$ make ruby
$ sudo make install

To test, run:

$ make rubytest

The binding currently supports:

- loading message types from descriptors.
- constructing message instances
- reading and writing their members
- parsing and serializing the messages
- all data types (including nested and repeated)

The binding does not currently support:

- defining message types directly in Ruby code.
- generating Ruby code for a .proto file.
- type-checking for setters
- homogenous / type-checked arrays
- default values

Because code generation is not currently implemented, the interface to import a specific message type is kind of clunky for the moment.