Stefan Monnier
I'd have thought it would have been simpler to just make the rule that -2 (no spaces between '-' and '2') would be a single lexeme,
But then x-2 won't mean "subtract 2 from x" but "call x with arg -2".
Well, since the normal typographical convention is that "hyphenated-words" are read as closely connected, I've always been in favour of including hyphen in variable names and using spaces to separate them from tokens, so perhaps it should just mean "the identifier 'x-2'". Though in the days of Unicode we could get round the whole thing by using code 0x002d for unary minus, 0x2010 in identifiers and 0x2212 for infix minus... and spend many a happy hour trying to tell which of the three was intended by some short horizontal line. -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2006-07-14)