Editing Oz (programming language) (section)

=== Message passing concurrency ===
The declarative concurrent model can be extended with [[message passing]] via simple semantics:
<syntaxhighlight lang="erlang">
declare
local Stream Port in
   Port = {NewPort Stream}
   {Send Port 1} % Stream is now 1|_ ('_' indicates an unbound and unnamed variable)
   {Send Port 2} % Stream is now 1|2|_ 
   ...
   {Send Port n} % Stream is now 1|2| .. |n|_
end 
</syntaxhighlight>

With a port and a thread, asynchronous agents can be defined:
<syntaxhighlight lang="erlang">
fun {NewAgent Init Fun}
   Msg Out in
   thread {FoldL Msg Fun Init Out} end
   {NewPort Msg}
end
</syntaxhighlight>