[Houshalter]

It's not infix math that's the problem, it's the ambiguity of "-". It can take two arguments in one context, or one in another (or just be a representation of a negative number without implying any function call at all.) If we just used a different symbol for subtraction, it would clear up a number of other parsing problems languages run into. Or you could just require negations to be done inside parentheses.

[coldtea]

Or just require whitespace for binary - and no whitespace for unary.

  res = -x ==> negative x

  res = c - x ==> c minus x

  res = - x ==> syntax error