Crystal bindings: add support for JSON messages.

zig-impl/crystal/some-crystal-app/src/json.cr

@@ -0,0 +1,43 @@
+require "json"
+
+class IPC::JSON
+	include ::JSON::Serializable
+
+	class_property type = -1
+	property     id   : ::JSON::Any?
+
+	def type
+		@@type
+	end
+
+	macro message(id, type, &block)
+		class {{id}} < ::IPC::JSON
+			include ::JSON::Serializable
+
+			@@type = {{type}}
+
+			{{yield}}
+		end
+	end
+end
+
+class IPC
+	def schedule(fd : Int32, message : IPC::JSON)
+		schedule fd, message.type.to_u8, message.to_json
+	end
+end
+
+# CAUTION: Only use this method on an Array(IPC::JSON.class)
+class Array(T)
+	def parse_ipc_json(message : IPCMessage::TypedMessage) : IPC::JSON?
+		message_type = find &.type.==(message.type)
+
+		payload = String.new message.payload
+
+		if message_type.nil?
+			raise "invalid message type (#{message.type})"
+		end
+
+		message_type.from_json payload
+	end
+end