operator >= method
Returns true if this precedence represents a tighter, or equal, binding
than other; that is, parsing ambiguities will be resolved in favor of
nesting the expression having precedence this within the expression
having precedence other, or, if the precedences are equal, parsing
ambiguities will be resolved according to the associativity of the
expression precedence.
Implementation
bool operator >=(Precedence other) => _index >= other._index;