## What is narcs? narcs is an encoder combinator library, essential the reverse of the decoder combinators provided by [scran][scran]. ## Examples For a 16 bit big endian unsigned length encoded string of "abc", returning iodata: ```erlang 1> (narcs_bytes:length_encoded(narcs_number:u(big, 16)))(<<"abc">>). [<<0,3>>,<<"abc">>] ``` For the same string to be null terminated: ```erlang 1> (narcs_bytes:null_terminated())(<<"abc">>). [<<"abc">>,0]. ``` Using a map of parameters, to encode some `flags` (32 bit integer), followed by some null terminated `bytes`: ```erlang 1> (narcs_sequence:sequence( [narcs_combinator:v(flags, narcs_number:u(big, 32)), narcs_combinator:v(bytes, narcs_bytes:null_terminated())])) (#{flags => 128, bytes => <<"hello world!">>}). [<<0,0,0,128>>,[<<"hello world!">>,0]] ``` Using a map of parameters, write each key as null terminated bytes and each value as a 16 bit numeric value: ```erlang 1> KV = (narcs_sequence:sequence( %% keys are atoms encoded as null terminated bytes: narcs_combinator:map_result( narcs_bytes:from_atom(), narcs_bytes:null_terminated()), %% values are 16 bit big endian: narcs_number:u(big, 16))). #Fun 2> KV(#{a => 1, b => 2, c => 3}). [[<<"b">>,0], <<0,2>>, [<<"a">>,0], <<0,1>>, [<<"c">>,0], <<0,3>>] ``` [scran]: https://github.com/shortishly/scran