Support lambda literal

Author: aycabta

lib/rdoc/ruby_lex.rb

@@ -494,6 +494,12 @@ def lex_init()
       Token(op)
     end
 
+    @OP.def_rules("->") do
+      |op, io|
+      @lex_state = :EXPR_ENDFN
+      Token(op)
+    end
+
     @OP.def_rules("!", "!=", "!~") do
       |op, io|
       @lex_state = :EXPR_BEG

lib/rdoc/ruby_token.rb

@@ -371,6 +371,7 @@ def Token(token, value = nil)
     [:TkCOLON3,     TkOp,   '::'],
     #[:OPASGN,       TkOp],               # +=, -=  etc. #
     [:TkASSOC,      TkOp,   "=>"],
+    [:TkLAMBDA,     TkOp,   "->"],
     [:TkQUESTION,   TkOp,   "?"], #?
     [:TkCOLON,      TkOp,   ":"],        #: