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 git@github.com:lasp-lang/lasp.git
$ cd lasp
$ make
Clone Lasp:
$ git clone https://github.com/lasp-lang/lasp.git
Run two shells
$ rebar3 shell --name a@127.0.0.1
$ rebar3 shell --name b@127.0.0.1
Exceute to node a:
1> lasp_peer_service:join('a@127.0.0.1').
ok
2> lasp_peer_service:members().
{ok,['a@127.0.0.1','b@127.0.0.1']}Execute node b:
1> lasp_peer_service:members().
{ok,['a@127.0.0.1','b@127.0.0.1']} 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}}, term_to_binary(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 checkIf using the Distributed Erlang backend, make sure that all nodes are configured to use the same cookie.
This blog post by @marianoguerra contains concise sample code.