+ var a = new Automaton.cla(c1.chars.first.code_point, c2.chars.first.code_point)
+ return a
+ end
+end
+
+redef class Nre_openclass
+ redef fun make_rfa: Automaton
+ do
+ var c1 = children[0].children[0].value
+ if c1.length != 1 then
+ print "Classes expect a single char"
+ exit(1)
+ abort
+ end
+ var a = new Automaton.cla(c1.chars.first.code_point, null)