adding document start version
initialize yaml start document event
emit document start event
add document end event
add scalar emit
emitter is working better
testing some dump events
wrap the emitter pointer with an object
adding squence start / end
adding mapping
exporting constants
add alias emit event
clean up document emitting error handling
simple string emitting works
basic list support
basic associated lists working
embedded lists work
handling null types
adding symbol support
support empty symbols