Re: Operator precedence

Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:

Are you saying that the order
  unary minus
  exponentiation
  binary minus
is somehow "wrong"?

It certainly feels like this to me. When thinking about the "why", I
could see two "arguments":

1. Unary and binary minus, while not identical operators, at least
visually are identical. Hence it reduces the cognitive load on the
reader of source code, who does not need to remember that unary minus
and binary minus are "on opposite sides of the 'exponentiation fence'".

2. Mathematical programming is algorithms (often beautifully typeset
with (La)TeX) transformed into more mundane ASCII-text representations
(which I see as a technical limitation). Using different operator
precedence depending on the visual representation is certainly confusing
if not dangerous (error-prone coding). Also, I do not see the benefit of
deviating from the mathematical convention.

With the rather new trend to use UTF characters in source code (lambda
and other greek letter, arrows) the visual distinction between printed
math and written source gets smaller, so it makes less and less sense to
use different conventions for the two.

Best regards

Axel