Method error

src/opt/opt_parse.cpp:609–613

private:

    void error(char const* msg) {
        std::ostringstream ous;
        ous << tok.line() << ": " << msg << " got: " << peek(0) << "\n";
        throw default_exception(ous.str());
    }
        
    symbol const& peek(unsigned i) { return tok.peek(i); }