Lasp is a programming model for synchronization-free computations.
Lasp requires Erlang 19 or greater. Once you have Erlang installed, do the following to install and build Lasp.
$ git clone [email protected]:lasp-lang/lasp.git
$ cd lasp
$ make
Clone Lasp:
$ git clone https://github.com/lasp-lang/lasp.git
Run two shells
$ rebar3 shell --name [email protected]
$ rebar3 shell --name [email protected]
Exceute to node a:
1> lasp_peer_service:join('[email protected]').
ok
2> lasp_peer_service:members().
{ok,['[email protected]','[email protected]']}
Execute node b:
1> lasp_peer_service:members().
{ok,['[email protected]','[email protected]']}
Go back to node a and run:
3> Content = #{what => i_am_an_awmap_value}.
% create a lasp CRDT
AwMapVarName = <<"awmap">>.
Key1 = <<"key1">>.
AwMapType = {state_awmap, [state_mvregister]}.
{ok, {AwMap, _, _, _}} = lasp:declare({AwMapVarName, AwMapType}, AwMapType).
% Update the CRDT with the content
{ok, _} = lasp:update(AwMap, {apply, Key1, {set, nil, Content}}, self()).
Go to node b and retrieve the content of the CRDT:
2> {ok,[{_, AwMapSet}]} = lasp:query({<<"awmap">>,{state_awmap,[state_mvregister]}}).
3> sets:to_list(AwMapSet).
% [#{what => i_am_an_awmap_value}]
You can run a Erlang shell where you can interact with a Lasp node by doing the following:
$ make shell
To run the test suite, which will execute all of the Lasp scenarios, use the following command.
$ make check
This blog post by @marianoguerra contains concise sample code.