squirrel

-module(squirrel@internal@gleam).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([is_identifier_char/1, to_function_name/1]).
-export_type([type/0, field/0]).

-type type() :: {list, type()} | {option, type()} | int | float | bool | string.

-type field() :: {field, binary(), type()}.

-spec is_identifier_char(binary()) -> boolean().
is_identifier_char(String) ->
    case String of
        <<"a"/utf8>> ->
            true;

        <<"b"/utf8>> ->
            true;

        <<"c"/utf8>> ->
            true;

        <<"d"/utf8>> ->
            true;

        <<"e"/utf8>> ->
            true;

        <<"f"/utf8>> ->
            true;

        <<"g"/utf8>> ->
            true;

        <<"h"/utf8>> ->
            true;

        <<"i"/utf8>> ->
            true;

        <<"j"/utf8>> ->
            true;

        <<"k"/utf8>> ->
            true;

        <<"l"/utf8>> ->
            true;

        <<"m"/utf8>> ->
            true;

        <<"n"/utf8>> ->
            true;

        <<"o"/utf8>> ->
            true;

        <<"p"/utf8>> ->
            true;

        <<"q"/utf8>> ->
            true;

        <<"r"/utf8>> ->
            true;

        <<"s"/utf8>> ->
            true;

        <<"t"/utf8>> ->
            true;

        <<"u"/utf8>> ->
            true;

        <<"v"/utf8>> ->
            true;

        <<"w"/utf8>> ->
            true;

        <<"x"/utf8>> ->
            true;

        <<"y"/utf8>> ->
            true;

        <<"z"/utf8>> ->
            true;

        <<"_"/utf8>> ->
            true;

        <<"0"/utf8>> ->
            true;

        <<"1"/utf8>> ->
            true;

        <<"2"/utf8>> ->
            true;

        <<"3"/utf8>> ->
            true;

        <<"4"/utf8>> ->
            true;

        <<"5"/utf8>> ->
            true;

        <<"6"/utf8>> ->
            true;

        <<"7"/utf8>> ->
            true;

        <<"8"/utf8>> ->
            true;

        <<"9"/utf8>> ->
            true;

        _ ->
            false
    end.

-spec to_function_name(binary()) -> binary().
to_function_name(Name) ->
    Filtered = begin
        _pipe = justin:snake_case(Name),
        _pipe@1 = gleam@string:to_graphemes(_pipe),
        _pipe@2 = gleam@list:filter(_pipe@1, fun is_identifier_char/1),
        gleam@string:join(_pipe@2, <<""/utf8>>)
    end,
    case Filtered of
        <<""/utf8>> ->
            <<"return"/utf8>>;

        <<"0"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"1"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"2"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"3"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"4"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"5"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"6"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"7"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"8"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"9"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        <<"_"/utf8, _/binary>> ->
            <<"return_"/utf8, Filtered/binary>>;

        _ ->
            Filtered
    end.