Question

I’m using ParseKit for objective-C which takes a BNF-like syntax for specifying grammers:

@start = command+;
command = new;
new = 'new' object ';';
object = 'house' | other;

Inclusion of the last line causes an error.
Basically I want to say an object can be a house or something else. The non-terminal element “other” is supposed to catch whatever word was there that wasn’t house.

Am I going about the “anything-here” idea the wrong way?

Thanks!

Answer 1

As suggested in the comments, you should either replace other with Word or add a new rule:

other = Word;

Since 'house' is a Word, you can also directly replace the object rule with:

object = Word;

A Word in ParseKit is a contiguous sequence of characters ([a-zA-Z]), numbers ([0-9]), and the symbols -, _, and ', that starts with a character. You can find more information about ParseKit tokens in the documentation.