> Just write code to parse the language in a straightforward way. This approach is why many consider parsing to be a solved problem, so it's certainly a valid

> Just write code to parse the language in a straightforward way. This approach is why many consider parsing to be a solved problem, so it's certainly a valid approach. However, it's not the only valid approach. For example, "straightforward" parsers often give terrible error messages: when the intended branch (eg. if/then/else) fails, the parser will backtrack and try a more general alternative (eg. a function call). Not only does this give an incorrect error (eg. "no such function 'esle'"), but it might actually succeed! In which case, the parser will be in the wrong state to parse the following text, and gives a non-sensical message (eg. "unexpected '('" several lines later). This is an important problem, since these messages can only be decyphered by those who know enough about the syntax to avoid hitting them very often! Inexperienced users will see error messages over and over again, and have no idea that they're being asked to fix non-existent errors in incorrect positions.