diff --git a/lib/test-suite b/lib/test-suite
index 6c15b3d60fe77e81ce0594e3f993726bb0f5f53f..7f00b8e36ad0b9d3d3eff2342fd72941f42f46e3 100644
--- a/lib/test-suite
+++ b/lib/test-suite
@@ -19,7 +19,7 @@
 token {
   parser token("95\xa2");
   test "95\xa2" --> "95\xa2";
-  test "95\xa2" --> fail;
+  test "95\xa3" --> fail;
 }
 
 ch {
@@ -87,7 +87,7 @@ uint8 {
 }
 
 int_range {
-  parser int_range(uint8(), 0x3, 0x10);
+  parser int_range(uint8(), 0x3, 0xa);
   test <05> --> u0x05;
   test <0b> --> fail;
 }
@@ -299,17 +299,17 @@ rightrec {
   test "aa" --> ['a',['a']];
   test "aaa" --> ['a',['a',['a']]];
 }
-
-ambiguous {
-  subparser $d = ch('d');
-  subparser $p = ch('+');
-  subparser $e = choice(sequence($e, $p, $e), $d);
-  # TODO: implement action/h_act_flatten
-  parser $e;
-  
-  test "d" --> 'd';
-  test "d+d" --> ['d','+','d'];
-  test "d+d+d" --> [['d','+','d'],'+','d'];
-}
+## Only for GLR
+#ambiguous {
+#  subparser $d = ch('d');
+#  subparser $p = ch('+');
+#  subparser $e = choice(sequence($e, $p, $e), $d);
+#  # TODO: implement action/h_act_flatten
+#  parser $e;
+#  
+#  test "d" --> 'd';
+#  test "d+d" --> ['d','+','d'];
+#  test "d+d+d" --> [['d','+','d'],'+','d'];
+#}
 
 
diff --git a/lib/tsgenruby.pl b/lib/tsgenruby.pl
index ebcc86a71042210543a2a12ba9786e079b4bceb8..ad83cf16e573d6c0275b3613ceeb8f8502a17364 100644
--- a/lib/tsgenruby.pl
+++ b/lib/tsgenruby.pl
@@ -96,7 +96,8 @@ pp_parser(num(Num)) --> !,
       "-0x", {RNum is -Num}; "0x", {RNum = Num} ),
     pp_hexnum_guts(RNum).
 pp_parser(char(C)) --> !,
-    "'", pp_char_guts(C), "'", !.
+        pp_parser(num(C)).
+        %"'", pp_char_guts(C), "'", !.
 
 pp_parser(ref(Name)) -->
     {atom_codes(Name,CName)},
@@ -198,7 +199,7 @@ pp_parse_result(char(C)) --> !,
 pp_parse_result(seq(Args)) --> !,
     "[", pp_result_seq(Args), "]".
 pp_parse_result(none) --> !,
-    "null".
+    "nil".
 pp_parse_result(uint(V)) --> !,
         pp_parser(num(V)).
 pp_parse_result(sint(V)) --> !,
diff --git a/src/bindings/ruby/lib/hammer/internal.rb b/src/bindings/ruby/lib/hammer/internal.rb
index 03bc45de9045d508bf123da1b4e943758c87864a..469dd730132c6972c3f12ba2e3e1c0495c57cacc 100644
--- a/src/bindings/ruby/lib/hammer/internal.rb
+++ b/src/bindings/ruby/lib/hammer/internal.rb
@@ -28,7 +28,7 @@ module Hammer
               :arena, :pointer,
               :elements, :pointer # HParsedToken**
 
-      def used
+      def length
         self[:used]
       end
 
@@ -36,6 +36,19 @@ module Hammer
         elem_array = FFI::Pointer.new(:pointer, self[:elements])
         return (0...self[:used]).map { |i| HParsedToken.new(elem_array[i].read_pointer) }
       end
+
+      #def [](idx)
+      #  raise ArgumentError, "Index out of range" unless idx >= 0 and idx < length
+      #  elem_array = FFI::Pointer.new(:pointer, self[:elements])
+      #  return HParsedToken.new(elem_array[i].read_pointer)
+      #end
+
+      def map(&code)
+        elements.map {|x| code.call x}
+      end
+      def each(&code)
+        elements.each {|x| code.call x}
+      end
     end
 
     class HBytes < FFI::Struct
@@ -72,6 +85,12 @@ module Hammer
               :index, :size_t,
               :bit_offset, :char
 
+      def normalize
+        # If I'm null, return nil.
+        return nil if null?
+        return self
+      end
+      
       def token_type
         self[:token_type]
       end
@@ -106,7 +125,7 @@ module Hammer
       def unmarshal
         case token_type
         when :sequence
-          self[:data][:seq].each {|x| x.unmarshal}
+          self[:data][:seq].map {|x| x.unmarshal}
         when :bytes
           self[:data][:bytes].token
         when :uint
@@ -127,7 +146,7 @@ module Hammer
               :arena, :pointer
 
       def ast
-        self[:ast]
+        self[:ast].normalize
       end
 
       def bit_length
@@ -140,13 +159,13 @@ module Hammer
     end
 
     # run a parser
-    attach_function :h_parse, [:h_parser, :string, :size_t], HParseResult.auto_ptr # TODO: Use :buffer_in instead of :string?
+    attach_function :h_parse, [:h_parser, :pointer, :size_t], HParseResult.auto_ptr # TODO: Use :buffer_in instead of :string?
 
     # build a parser
     attach_function :h_token, [:buffer_in, :size_t], :h_parser
     attach_function :h_ch, [:uint8], :h_parser
     attach_function :h_ch_range, [:uint8, :uint8], :h_parser
-    attach_function :h_int_range, [:int64, :int64], :h_parser
+    attach_function :h_int_range, [:h_parser, :int64, :int64], :h_parser
     attach_function :h_bits, [:size_t, :bool], :h_parser
     attach_function :h_int64, [], :h_parser
     attach_function :h_int32, [], :h_parser
@@ -160,8 +179,8 @@ module Hammer
     attach_function :h_left,   [:h_parser, :h_parser], :h_parser
     attach_function :h_right,  [:h_parser, :h_parser], :h_parser
     attach_function :h_middle, [:h_parser, :h_parser, :h_parser], :h_parser
-    #attach_function :h_in, [:buffer_in, :size_t], :h_parser
-    #attach_function :h_not_in, [:buffer_in, :size_t], :h_parser
+    attach_function :h_in, [:pointer, :size_t], :h_parser
+    attach_function :h_not_in, [:pointer, :size_t], :h_parser
     attach_function :h_end_p, [], :h_parser
     attach_function :h_nothing_p, [], :h_parser
     attach_function :h_sequence, [:varargs], :h_parser
@@ -171,7 +190,7 @@ module Hammer
     attach_function :h_xor, [:h_parser, :h_parser], :h_parser
     attach_function :h_many, [:h_parser], :h_parser
     attach_function :h_many1, [:h_parser], :h_parser
-    #attach_function :h_repeat_n, [:h_parser, :size_t], :h_parser
+    attach_function :h_repeat_n, [:h_parser, :size_t], :h_parser
     attach_function :h_optional, [:h_parser], :h_parser
     attach_function :h_ignore, [:h_parser], :h_parser
     attach_function :h_sepBy, [:h_parser, :h_parser], :h_parser
diff --git a/src/bindings/ruby/lib/hammer/parser.rb b/src/bindings/ruby/lib/hammer/parser.rb
index b496558fba4661dedf45823340b80b903c7adb54..4d9f43259c0b396bc92a6633741ba9a8fcff30fc 100644
--- a/src/bindings/ruby/lib/hammer/parser.rb
+++ b/src/bindings/ruby/lib/hammer/parser.rb
@@ -25,7 +25,8 @@ module Hammer
       raise RuntimeError, '@h_parser is nil' if @h_parser.nil?
       raise ArgumentError, 'expecting a String' unless data.is_a? String # TODO: Not needed, FFI checks that.
 
-      result = Hammer::Internal.h_parse(@h_parser, data, data.bytesize)
+      ibuf = FFI::MemoryPointer.from_string(data)
+      result = Hammer::Internal.h_parse(@h_parser, ibuf, data.bytesize) # Don't include the trailing null
       if result.null?
         return nil
       else
@@ -73,13 +74,54 @@ module Hammer
       return Hammer::Parser.new(:token, h_parser, buffer)
     end
 
-    def self.ch(num)
-      raise ArgumentError, 'expecting a Fixnum in 0..255' unless num.is_a?(Fixnum) and num.between?(0, 255)
+    def self.marshal_ch_arg(num)
+      if num.is_a?(String)
+        raise ArgumentError, "Expecting either a fixnum in 0..255 or a single-byte String" unless num.bytes.length == 1
+        num = num.bytes[0]
+      end
+      raise ArgumentError, 'Expecting a Fixnum in 0..255 or a single-byte String' unless num.is_a?(Fixnum) and num.between?(0, 255)
+      return num
+    end
+    private_class_method :marshal_ch_arg
+    
+    def self.ch(ch)
+      num = marshal_ch_arg(ch)
       h_parser = Hammer::Internal.h_ch(num)
 
       return Hammer::Parser.new(:ch, h_parser, nil)
     end
 
+    def self.ch_range(ch1, ch2)
+      ch1 = marshal_ch_arg(ch1)
+      ch2 = marshal_ch_arg(ch2)
+      h_parser = Hammer::Internal.h_ch_range(ch1, ch2)
+      return Hammer::Parser.new(:ch_range, h_parser, nil)
+    end
+
+    def self.int_range(parser, i1, i2)
+      h_parser = Hammer::Internal.h_int_range(parser.h_parser, i1, i2)
+      return Hammer::Parser.new(:int_range, h_parser, nil)
+    end
+
+    def self.in(charset)
+      raise ArgumentError, "Expected a String" unless charset.is_a?(String)
+      ibuf = FFI::MemoryPointer.from_string(charset)
+      h_parser = Hammer::Internal.h_in(ibuf, charset.bytesize)
+      return Hammer::Parser.new(:in, h_parser, nil)
+    end
+
+    def self.repeat_n(parser, count)
+      h_parser = Hammer::Internal.h_repeat_n(parser.h_parser, count)
+      return Hammer::Parser.new(:repeat_n, h_parser, nil)
+    end
+
+    def self.not_in(charset)
+      raise ArgumentError, "Expected a String" unless charset.is_a?(String)
+      ibuf = FFI::MemoryPointer.from_string(charset)
+      h_parser = Hammer::Internal.h_not_in(ibuf, charset.bytesize)
+      return Hammer::Parser.new(:not_in, h_parser, nil)
+    end
+
     # Defines a parser constructor with the given name.
     # Options:
     #   hammer_function: name of the hammer function to call (default: 'h_'+name)
diff --git a/src/bindings/ruby/lib/minitest/hamer-parser_plugin.rb b/src/bindings/ruby/lib/minitest/hamer-parser_plugin.rb
index 393a540bb39a89a656d48ee2fd8efe8ef128c294..a23d8b9a639ef7efbd43a8ce277aeb36492d2a9e 100644
--- a/src/bindings/ruby/lib/minitest/hamer-parser_plugin.rb
+++ b/src/bindings/ruby/lib/minitest/hamer-parser_plugin.rb
@@ -18,7 +18,10 @@ module Minitest
     def refute_parse_ok(parser, probe)
       refute_nil parser, "Parser must not be nil (this is a problem with your test)"
       parse_result = parser.parse(probe)
-      assert_nil parse_result, "Parse succeeded unexpectedly with " + parse_result.ast.inspect
+
+      if not parse_result.nil?
+        assert_nil parse_result, "Parse succeeded unexpectedly with " + parse_result.ast.inspect
+      end
     end
   end
   
diff --git a/src/bindings/ruby/test/autogen_test.rb b/src/bindings/ruby/test/autogen_test.rb
index a2566bc066c6287198b7c84ad6002526a943390a..93a0c7a5452611a88e257566547f25952c8864ce 100644
--- a/src/bindings/ruby/test/autogen_test.rb
+++ b/src/bindings/ruby/test/autogen_test.rb
@@ -13,7 +13,7 @@ class TestToken < Minitest::Test
   end
 
   def test_2
-    refute_parse_ok @parser_1, "95\xa2"
+    refute_parse_ok @parser_1, "95\xa3"
   end
 end
 
@@ -25,7 +25,7 @@ class TestCh < Minitest::Test
   end
 
   def test_1
-    assert_parse_ok @parser_1, "\xa2", '\xa2'
+    assert_parse_ok @parser_1, "\xa2", 0xa2
   end
 
   def test_2
@@ -41,7 +41,7 @@ class TestChRange < Minitest::Test
   end
 
   def test_1
-    assert_parse_ok @parser_1, "b", 'b'
+    assert_parse_ok @parser_1, "b", 0x62
   end
 
   def test_2
@@ -197,7 +197,7 @@ class TestIntRange < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.int_range(h.uint8, 0x3, 0x10)
+    @parser_1 = h.int_range(h.uint8, 0x3, 0xa)
   end
 
   def test_1
@@ -218,19 +218,19 @@ class TestWhitespace < Minitest::Test
   end
 
   def test_1
-    assert_parse_ok @parser_1, "a", 'a'
+    assert_parse_ok @parser_1, "a", 0x61
   end
 
   def test_2
-    assert_parse_ok @parser_1, " a", 'a'
+    assert_parse_ok @parser_1, " a", 0x61
   end
 
   def test_3
-    assert_parse_ok @parser_1, "  a", 'a'
+    assert_parse_ok @parser_1, "  a", 0x61
   end
 
   def test_4
-    assert_parse_ok @parser_1, "\x09a", 'a'
+    assert_parse_ok @parser_1, "\x09a", 0x61
   end
 
   def test_5
@@ -238,11 +238,11 @@ class TestWhitespace < Minitest::Test
   end
 
   def test_6
-    assert_parse_ok @parser_2, "", null
+    assert_parse_ok @parser_2, "", nil
   end
 
   def test_7
-    assert_parse_ok @parser_2, "  ", null
+    assert_parse_ok @parser_2, "  ", nil
   end
 
   def test_8
@@ -258,7 +258,7 @@ class TestLeft < Minitest::Test
   end
 
   def test_1
-    assert_parse_ok @parser_1, "a ", 'a'
+    assert_parse_ok @parser_1, "a ", 0x61
   end
 
   def test_2
@@ -278,11 +278,11 @@ class TestMiddle < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.middle(h.ch(' '), h.ch('a'), h.ch(' '))
+    @parser_1 = h.middle(h.ch(0x20), h.ch(0x61), h.ch(0x20))
   end
 
   def test_1
-    assert_parse_ok @parser_1, " a ", 'a'
+    assert_parse_ok @parser_1, " a ", 0x61
   end
 
   def test_2
@@ -318,7 +318,7 @@ class TestIn < Minitest::Test
   end
 
   def test_1
-    assert_parse_ok @parser_1, "b", 'b'
+    assert_parse_ok @parser_1, "b", 0x62
   end
 
   def test_2
@@ -334,7 +334,7 @@ class TestNotIn < Minitest::Test
   end
 
   def test_1
-    assert_parse_ok @parser_1, "d", 'd'
+    assert_parse_ok @parser_1, "d", 0x64
   end
 
   def test_2
@@ -346,11 +346,11 @@ class TestEndP < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.sequence(h.ch('a'), h.end_p)
+    @parser_1 = h.sequence(h.ch(0x61), h.end_p)
   end
 
   def test_1
-    assert_parse_ok @parser_1, "a", ['a']
+    assert_parse_ok @parser_1, "a", [0x61]
   end
 
   def test_2
@@ -374,12 +374,12 @@ class TestSequence < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.sequence(h.ch('a'), h.ch('b'))
-    @parser_2 = h.sequence(h.ch('a'), h.whitespace(h.ch('b')))
+    @parser_1 = h.sequence(h.ch(0x61), h.ch(0x62))
+    @parser_2 = h.sequence(h.ch(0x61), h.whitespace(h.ch(0x62)))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "ab", ['a', 'b']
+    assert_parse_ok @parser_1, "ab", [0x61, 0x62]
   end
 
   def test_2
@@ -391,15 +391,15 @@ class TestSequence < Minitest::Test
   end
 
   def test_4
-    assert_parse_ok @parser_2, "ab", ['a', 'b']
+    assert_parse_ok @parser_2, "ab", [0x61, 0x62]
   end
 
   def test_5
-    assert_parse_ok @parser_2, "a b", ['a', 'b']
+    assert_parse_ok @parser_2, "a b", [0x61, 0x62]
   end
 
   def test_6
-    assert_parse_ok @parser_2, "a  b", ['a', 'b']
+    assert_parse_ok @parser_2, "a  b", [0x61, 0x62]
   end
 end
 
@@ -407,19 +407,19 @@ class TestChoice < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.choice(h.ch('a'), h.ch('b'))
+    @parser_1 = h.choice(h.ch(0x61), h.ch(0x62))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "a", 'a'
+    assert_parse_ok @parser_1, "a", 0x61
   end
 
   def test_2
-    assert_parse_ok @parser_1, "b", 'b'
+    assert_parse_ok @parser_1, "b", 0x62
   end
 
   def test_3
-    assert_parse_ok @parser_1, "ab", 'a'
+    assert_parse_ok @parser_1, "ab", 0x61
   end
 
   def test_4
@@ -431,12 +431,12 @@ class TestButnot < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.butnot(h.ch('a'), h.token("ab"))
-    @parser_2 = h.butnot(h.ch_range('0', '9'), h.ch('6'))
+    @parser_1 = h.butnot(h.ch(0x61), h.token("ab"))
+    @parser_2 = h.butnot(h.ch_range(0x30, 0x39), h.ch(0x36))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "a", 'a'
+    assert_parse_ok @parser_1, "a", 0x61
   end
 
   def test_2
@@ -444,11 +444,11 @@ class TestButnot < Minitest::Test
   end
 
   def test_3
-    assert_parse_ok @parser_1, "aa", 'a'
+    assert_parse_ok @parser_1, "aa", 0x61
   end
 
   def test_4
-    assert_parse_ok @parser_2, "5", '5'
+    assert_parse_ok @parser_2, "5", 0x35
   end
 
   def test_5
@@ -460,7 +460,7 @@ class TestDifference < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.difference(h.token("ab"), h.ch('a'))
+    @parser_1 = h.difference(h.token("ab"), h.ch(0x61))
   end
 
   def test_1
@@ -476,15 +476,15 @@ class TestXor < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.xor(h.ch_range('0', '6'), h.ch_range('5', '9'))
+    @parser_1 = h.xor(h.ch_range(0x30, 0x36), h.ch_range(0x35, 0x39))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "0", '0'
+    assert_parse_ok @parser_1, "0", 0x30
   end
 
   def test_2
-    assert_parse_ok @parser_1, "9", '9'
+    assert_parse_ok @parser_1, "9", 0x39
   end
 
   def test_3
@@ -500,7 +500,7 @@ class TestMany < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.many(h.choice(h.ch('a'), h.ch('b')))
+    @parser_1 = h.many(h.choice(h.ch(0x61), h.ch(0x62)))
   end
 
   def test_1
@@ -508,15 +508,15 @@ class TestMany < Minitest::Test
   end
 
   def test_2
-    assert_parse_ok @parser_1, "a", ['a']
+    assert_parse_ok @parser_1, "a", [0x61]
   end
 
   def test_3
-    assert_parse_ok @parser_1, "b", ['b']
+    assert_parse_ok @parser_1, "b", [0x62]
   end
 
   def test_4
-    assert_parse_ok @parser_1, "aabbaba", ['a', 'a', 'b', 'b', 'a', 'b', 'a']
+    assert_parse_ok @parser_1, "aabbaba", [0x61, 0x61, 0x62, 0x62, 0x61, 0x62, 0x61]
   end
 end
 
@@ -524,7 +524,7 @@ class TestMany1 < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.many1(h.choice(h.ch('a'), h.ch('b')))
+    @parser_1 = h.many1(h.choice(h.ch(0x61), h.ch(0x62)))
   end
 
   def test_1
@@ -532,15 +532,15 @@ class TestMany1 < Minitest::Test
   end
 
   def test_2
-    assert_parse_ok @parser_1, "a", ['a']
+    assert_parse_ok @parser_1, "a", [0x61]
   end
 
   def test_3
-    assert_parse_ok @parser_1, "b", ['b']
+    assert_parse_ok @parser_1, "b", [0x62]
   end
 
   def test_4
-    assert_parse_ok @parser_1, "aabbaba", ['a', 'a', 'b', 'b', 'a', 'b', 'a']
+    assert_parse_ok @parser_1, "aabbaba", [0x61, 0x61, 0x62, 0x62, 0x61, 0x62, 0x61]
   end
 
   def test_5
@@ -552,7 +552,7 @@ class TestRepeatN < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.repeat_n(h.choice(h.ch('a'), h.ch('b')), 0x2)
+    @parser_1 = h.repeat_n(h.choice(h.ch(0x61), h.ch(0x62)), 0x2)
   end
 
   def test_1
@@ -560,7 +560,7 @@ class TestRepeatN < Minitest::Test
   end
 
   def test_2
-    assert_parse_ok @parser_1, "abdef", ['a', 'b']
+    assert_parse_ok @parser_1, "abdef", [0x61, 0x62]
   end
 
   def test_3
@@ -572,19 +572,19 @@ class TestOptional < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.sequence(h.ch('a'), h.optional(h.choice(h.ch('b'), h.ch('c'))), h.ch('d'))
+    @parser_1 = h.sequence(h.ch(0x61), h.optional(h.choice(h.ch(0x62), h.ch(0x63))), h.ch(0x64))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "abd", ['a', 'b', 'd']
+    assert_parse_ok @parser_1, "abd", [0x61, 0x62, 0x64]
   end
 
   def test_2
-    assert_parse_ok @parser_1, "acd", ['a', 'c', 'd']
+    assert_parse_ok @parser_1, "acd", [0x61, 0x63, 0x64]
   end
 
   def test_3
-    assert_parse_ok @parser_1, "ad", ['a', null, 'd']
+    assert_parse_ok @parser_1, "ad", [0x61, nil, 0x64]
   end
 
   def test_4
@@ -604,11 +604,11 @@ class TestIgnore < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.sequence(h.ch('a'), h.ignore(h.ch('b')), h.ch('c'))
+    @parser_1 = h.sequence(h.ch(0x61), h.ignore(h.ch(0x62)), h.ch(0x63))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "abc", ['a', 'c']
+    assert_parse_ok @parser_1, "abc", [0x61, 0x63]
   end
 
   def test_2
@@ -620,23 +620,23 @@ class TestSepBy < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.sepBy(h.choice(h.ch('1'), h.ch('2'), h.ch('3')), h.ch(','))
+    @parser_1 = h.sepBy(h.choice(h.ch(0x31), h.ch(0x32), h.ch(0x33)), h.ch(0x2c))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "1,2,3", ['1', '2', '3']
+    assert_parse_ok @parser_1, "1,2,3", [0x31, 0x32, 0x33]
   end
 
   def test_2
-    assert_parse_ok @parser_1, "1,3,2", ['1', '3', '2']
+    assert_parse_ok @parser_1, "1,3,2", [0x31, 0x33, 0x32]
   end
 
   def test_3
-    assert_parse_ok @parser_1, "1,3", ['1', '3']
+    assert_parse_ok @parser_1, "1,3", [0x31, 0x33]
   end
 
   def test_4
-    assert_parse_ok @parser_1, "3", ['3']
+    assert_parse_ok @parser_1, "3", [0x33]
   end
 
   def test_5
@@ -648,23 +648,23 @@ class TestSepBy1 < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.sepBy1(h.choice(h.ch('1'), h.ch('2'), h.ch('3')), h.ch(','))
+    @parser_1 = h.sepBy1(h.choice(h.ch(0x31), h.ch(0x32), h.ch(0x33)), h.ch(0x2c))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "1,2,3", ['1', '2', '3']
+    assert_parse_ok @parser_1, "1,2,3", [0x31, 0x32, 0x33]
   end
 
   def test_2
-    assert_parse_ok @parser_1, "1,3,2", ['1', '3', '2']
+    assert_parse_ok @parser_1, "1,3,2", [0x31, 0x33, 0x32]
   end
 
   def test_3
-    assert_parse_ok @parser_1, "1,3", ['1', '3']
+    assert_parse_ok @parser_1, "1,3", [0x31, 0x33]
   end
 
   def test_4
-    assert_parse_ok @parser_1, "3", ['3']
+    assert_parse_ok @parser_1, "3", [0x33]
   end
 
   def test_5
@@ -676,13 +676,13 @@ class TestAnd < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.sequence(h.and(h.ch('0')), h.ch('0'))
-    @parser_2 = h.sequence(h.and(h.ch('0')), h.ch('1'))
-    @parser_3 = h.sequence(h.ch('1'), h.and(h.ch('2')))
+    @parser_1 = h.sequence(h.and(h.ch(0x30)), h.ch(0x30))
+    @parser_2 = h.sequence(h.and(h.ch(0x30)), h.ch(0x31))
+    @parser_3 = h.sequence(h.ch(0x31), h.and(h.ch(0x32)))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "0", ['0']
+    assert_parse_ok @parser_1, "0", [0x30]
   end
 
   def test_2
@@ -698,7 +698,7 @@ class TestAnd < Minitest::Test
   end
 
   def test_5
-    assert_parse_ok @parser_3, "12", ['1']
+    assert_parse_ok @parser_3, "12", [0x31]
   end
 
   def test_6
@@ -710,12 +710,12 @@ class TestNot < Minitest::Test
   def setup
     super
     h = Hammer::Parser
-    @parser_1 = h.sequence(h.ch('a'), h.choice(h.token("+"), h.token("++")), h.ch('b'))
-    @parser_2 = h.sequence(h.ch('a'), h.choice(h.sequence(h.token("+"), h.not(h.ch('+'))), h.token("++")), h.ch('b'))
+    @parser_1 = h.sequence(h.ch(0x61), h.choice(h.token("+"), h.token("++")), h.ch(0x62))
+    @parser_2 = h.sequence(h.ch(0x61), h.choice(h.sequence(h.token("+"), h.not(h.ch(0x2b))), h.token("++")), h.ch(0x62))
   end
 
   def test_1
-    assert_parse_ok @parser_1, "a+b", ['a', "+", 'b']
+    assert_parse_ok @parser_1, "a+b", [0x61, "+", 0x62]
   end
 
   def test_2
@@ -723,11 +723,11 @@ class TestNot < Minitest::Test
   end
 
   def test_3
-    assert_parse_ok @parser_2, "a+b", ['a', ["+"], 'b']
+    assert_parse_ok @parser_2, "a+b", [0x61, ["+"], 0x62]
   end
 
   def test_4
-    assert_parse_ok @parser_2, "a++b", ['a', "++", 'b']
+    assert_parse_ok @parser_2, "a++b", [0x61, "++", 0x62]
   end
 end
 
@@ -736,46 +736,20 @@ class TestRightrec < Minitest::Test
     super
     h = Hammer::Parser
     @sp_rr = h.indirect
-    @sp_rr.bind h.choice(h.sequence(h.ch('a'), @sp_rr), h.epsilon_p)
+    @sp_rr.bind h.choice(h.sequence(h.ch(0x61), @sp_rr), h.epsilon_p)
     @parser_1 = @sp_rr
   end
 
   def test_1
-    assert_parse_ok @parser_1, "a", ['a']
+    assert_parse_ok @parser_1, "a", [0x61]
   end
 
   def test_2
-    assert_parse_ok @parser_1, "aa", ['a', ['a']]
+    assert_parse_ok @parser_1, "aa", [0x61, [0x61]]
   end
 
   def test_3
-    assert_parse_ok @parser_1, "aaa", ['a', ['a', ['a']]]
-  end
-end
-
-class TestAmbiguous < Minitest::Test
-  def setup
-    super
-    h = Hammer::Parser
-    @sp_d = h.indirect
-    @sp_p = h.indirect
-    @sp_e = h.indirect
-    @sp_d.bind h.ch('d')
-    @sp_p.bind h.ch('+')
-    @sp_e.bind h.choice(h.sequence(@sp_e, @sp_p, @sp_e), @sp_d)
-    @parser_1 = @sp_e
-  end
-
-  def test_1
-    assert_parse_ok @parser_1, "d", 'd'
-  end
-
-  def test_2
-    assert_parse_ok @parser_1, "d+d", ['d', '+', 'd']
-  end
-
-  def test_3
-    assert_parse_ok @parser_1, "d+d+d", [['d', '+', 'd'], '+', 'd']
+    assert_parse_ok @parser_1, "aaa", [0x61, [0x61, [0x61]]]
   end
 end