is_a! and is_not! can consume the whole input
is_a! and is_not! can consume the whole input

Fix #84

meh/nom,ahenry/nom,daboross/nom,Geal/nom,bluss/nom,colinsurprenant/nom,Keruspe/nom,AndyShiue/nom,alan-andrade/nom,pwoolcoc/nom,sourrust/nom