parser: factor out _trygetfunc() that extracts function name and arguments...
parser: factor out _trygetfunc() that extracts function name and arguments
This provides a customization point for templater. In templater, there are
two ways to call a unary function: func(x) and x|func. They are processed
differently in templater due to historical reasons, but they should be
handled in the same way while expanding aliases. In short, x|func should be
processed as syntactic sugar for func(x).
_funcnode and _getlist() are replaced by _trygetfunc().
