(Changed in version 2.9.0) The p0 call-by-name arguments is evaluated at most once per constructed Parser object, instead of on every need that arises during parsing.
A parser that matches elements of a given type.
A parser that matches elements of a given type. This is useful if you have
a hierarchy of traits that extend from Elem and want to easily be able to
match certain classes of tokens.
Mix-in utility code to assist with Parser development.