Scanner remains stuck on incorrect syntax

[danfilip]

hello,

i've encountered an issue in the scanner when accidentally using "=" instead of "==" in an expression.

here's the test:

timeout_test_() ->
    [
        {timeout, 20, fun timeout/0}
    ].

timeout() ->
    Map = #{
        <<"root_key">> =>
            [
                #{<<"id">> => <<"95101841147">>, <<"type">> => <<"type1">>},
                #{<<"id">> => <<"1803962935345">>, <<"type">> => <<"type2">>}
            ]
    },

    R = ejsonpath:q("$.root_key[?(@.type = 'type2')].id", Map). % change = with == and it works

and here's the stacktrace after it's killed by eunit:

Test case timeout!
exception exit: killed
  in function  ejsonpath_scan:yystate/6 (src/ejsonpath_scan.erl, line 310)
  in call from ejsonpath_scan:string/4 (../../../../../.asdf/installs/erlang/25.2.2/lib/parsetools-2.4.1/include/leexinc.hrl, line 32)
  in call from ejsonpath:q/4 (src/ejsonpath.erl, line 64)
  in call from kycurl_jsonpath:timeout_test/0 (test/kycurl_jsonpath.erl, line 111)
  in call from eunit_test:'-mf_wrapper/2-fun-0-'/2 (eunit_test.erl, line 273)
  in call from eunit_test:run_testfun/1 (eunit_test.erl, line 71)
  in call from eunit_proc:run_test/1 (eunit_proc.erl, line 531)
  in call from eunit_proc:with_timeout/3 (eunit_proc.erl, line 356)

regardless of the timeout, the scanner remains stuck.