Write value over one signed byte, following 1 metadata byte

Require: value >= -128 and value <= 127

Property definitions

msgpack :: write $ Writer :: write_msgpack_int8
	# Write `value` over one signed byte, following 1 metadata byte
	#
	# Require: `value >= -128  and value <= 127`
	fun write_msgpack_int8(value: Int)
	do
		write_byte 0xD0
		write_bytes value.to_bytes(n_bytes=1)
	end
lib/msgpack/write.nit:103,2--110,4