Function readClassMetadata

pj_scripting/src/luau_engine.cpp:366–377

Read metadata (NOT create) from the class table on top of `L` into a FilterClass. Leaves the stack as found. Returns an error string.

// Read metadata (NOT create) from the class table on top of `L` into a
// FilterClass. Leaves the stack as found. Returns an error string.
std::string readClassMetadata(lua_State* L, FilterClass& fc) {
  const int idx = lua_gettop(L);
  fc.id = stringField(L, idx, "id");
  fc.name = stringField(L, idx, "name", fc.id);
  if (fc.id.empty()) {
    return "filter class is missing its `id`";
  }
  fc.description = stringField(L, idx, "description");
  fc.version = stringField(L, idx, "version");
  fc.output_kind = stringField(L, idx, "output", "double");
  return readParameters(L, idx, fc.parameters);
}

// Bind an instance method (`calculate`/`reset`) by name WITHOUT triggering any
// metamethod: first a raw field on the instance, else a raw lookup through a