I have a piece of JSON string, which I want to parse in Erlang. It looks like:
({ id1 : [\"str1\", \"str2\", \"str3\"], id2 : [\"str4\", \"str5\"]})
Your JSON keys are not valid according to https://www.ietf.org/rfc/rfc4627.txt. Once you correct it, there are plenty of JSON libraries for Erlang, my favorite is JSX(https://github.com/talentdeficit/jsx/):
MyJSON = { "id1" : ["str1", "str2", "str3"], "id2" : ["str4", "str5"]},
jsx:decode(MyJSON, [return_maps]).
And it will return an Erlang map data structure that can be manipulated to your needs http://learnyousomeerlang.com/maps