needs_parens: Determine whether parentheses are needed to preserve meaning
Description
Parentheses are needed when the inner operator has lower precedence
than the parent, because without them the human reader might
misinterpret the grouping.
Usage
needs_parens(inner_op, outer_op)
Arguments
- inner_op
The operator inside the parentheses (or NULL)
- outer_op
The operator outside (parent context, or NULL)