Unary Minus about coffeescript HOT 3 CLOSED

Hang on a sec, that is a syntax error, right? Two numbers next to each other, three and negative four. I think it would be strange if it parsed as a subtraction, and it would still be a syntax error if it was caught by the parser, which does understand unary minuses:

(-3 - -x)

Compiles, with negative x as a unary operator caught by the parser. Is there a reason that numbers shouldn't be allowed to be negative while lexing? It's just one less node to compile.

from coffeescript.

No, it isn't a syntax error. It's valid in JS and C and any other language with a unary minus. The problem is more exacerbated if you write it like this:

(3-4)

The unary minus case should only be exercised if the binary minus has been tried.

So, in formal logic with only numbers, unary minus and binary minus:
Num is all numbers.

x Num
------
x Atom

x Atom
------
-x Atom

x Atom
------
x Expr

x Expr y Expr
-------------
x - y Expr

from coffeescript.

Alright, I'm persuaded. I've removed the optional minus from the lexer, and added a test for your first example. Your cases now compile as expected. Closing the ticket...

from coffeescript.