domain-0.1.1: samples/1.yaml

# Service can be either located on the network or
# by a socket file.
#
# Choice between two or more types can be encoded using
# "sum" type composition, which you may also know as
# "union" or "variant". That's what we use here.
ServiceAddress:
  sum:
    network: NetworkAddress
    local: FilePath

# Network address is a combination of transport protocol,
# host and port. All those three things at once.
#
# "product" type composition lets us encode that.
# You may also know it as "record" or "tuple".
NetworkAddress:
  product:
    protocol: TransportProtocol
    host: Host
    port: Word16

# Transport protocol is either TCP or UDP.
# We encode that using enumeration.
TransportProtocol:
  enum:
    - tcp
    - udp

# Host can be adressed by either an IP or its name,
# so "sum" again.
Host:
  sum:
    ip: Ip
    name: Text

# IP can be either of version 4 or version 6.
# We encode it as a sum over words of the accordingly required
# amount of bits.
Ip:
  sum:
    v4: Word32
    v6:
      # Since the standard lib lacks a definition
      # of a 128-bit word, we define a custom one
      # as a product of two 64-bit words.
      product:
        part1: Word64
        part2: Word64