HLL::Grammar predefined operator predecence categories

term:           3, 3.1415, 'pi'
infix:          3 + 2, 4 * 7, $x && $y
prefix:         -$a, --$a, ++$b
postfix:        $a++, $b--
circumfix:      (3+4), ['a', 'b']
postcircumfix:  @a[0], %h{'x'}, &foo()

Grammar and action subclasses can add new categories or redefine existing categories.