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diff --git a/antlr-3.4/runtime/Ruby/test/functional/ast-output/auto-ast.rb b/antlr-3.4/runtime/Ruby/test/functional/ast-output/auto-ast.rb
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+#!/usr/bin/ruby
+# encoding: utf-8
+
+require 'antlr3/test/functional'
+
+class TestAutoAST < ANTLR3::Test::Functional
+  
+  def parse( grammar, rule, input, expect_errors = false )
+    @grammar = inline_grammar( grammar )
+    compile_and_load @grammar
+    grammar_module = self.class.const_get( @grammar.name )
+    
+    grammar_module::Lexer.send( :include, ANTLR3::Test::CollectErrors )
+    grammar_module::Lexer.send( :include, ANTLR3::Test::CaptureOutput )
+    grammar_module::Parser.send( :include, ANTLR3::Test::CollectErrors )
+    grammar_module::Parser.send( :include, ANTLR3::Test::CaptureOutput )
+    
+    lexer  = grammar_module::Lexer.new( input )
+    parser = grammar_module::Parser.new( lexer )
+    
+    r = parser.send( rule )
+    parser.reported_errors.should be_empty unless expect_errors
+    result = ''
+    
+    unless r.nil?
+      result += r.result if r.respond_to?( :result )
+      result += r.tree.inspect if r.tree
+    end
+    return( expect_errors ? [ result, parser.reported_errors ] : result )
+  end
+  
+  def tree_parse( grammar, tree_grammar, rule, tree_rule, input )
+    @grammar = inline_grammar( grammar )
+    @tree_grammar = inline_grammar( tree_grammar )
+    compile_and_load @grammar
+    compile_and_load @tree_grammar
+    
+    grammar_module = self.class.const_get( @grammar.name )
+    tree_grammar_module = self.class.const_get( @tree_grammar.name )
+    
+    grammar_module::Lexer.send( :include, ANTLR3::Test::CollectErrors )
+    grammar_module::Lexer.send( :include, ANTLR3::Test::CaptureOutput )
+    grammar_module::Parser.send( :include, ANTLR3::Test::CollectErrors )
+    grammar_module::Parser.send( :include, ANTLR3::Test::CaptureOutput )
+    tree_grammar_module::TreeParser.send( :include, ANTLR3::Test::CollectErrors )
+    tree_grammar_module::TreeParser.send( :include, ANTLR3::Test::CaptureOutput )
+    
+    lexer  = grammar_module::Lexer.new( input )
+    parser = grammar.module::Parser.new( lexer )
+    r = parser.send( rule )
+    nodes = ANTLR3::CommonTreeNodeStream( r.tree )
+    nodes.token_stream = parser.input
+    walker = tree_grammar_module::TreeParser.new( nodes )
+    r = walker.send( tree_rule )
+    
+    return( r ? r.tree.inspect : '' )
+  end
+  
+  
+  example 'flat token list' do
+    result = parse( <<-'END', :a, 'abc 34' )
+      grammar TokenList;
+      options {language=Ruby;output=AST;}
+      a : ID INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;};
+    END
+    result.should == 'abc 34'
+  end
+  
+  example 'token list in a single-alternative subrule' do
+    result = parse( <<-'END', :a, 'abc 34' )
+      grammar TokenListInSingleAltBlock;
+      options {language=Ruby;output=AST;}
+      a : (ID INT) ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == 'abc 34'
+  end
+  
+  example "simple root at the outer level via the `^' operator" do
+    result = parse( <<-'END', :a, 'abc 34' )
+      grammar SimpleRootAtOuterLevel;
+      options {language=Ruby;output=AST;}
+      a : ID^ INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(abc 34)'
+  end
+  
+  example "outer-level root changing token order from the `^' operator" do
+    result = parse( <<-'END', :a, '34 abc' )
+      grammar SimpleRootAtOuterLevelReverse;
+      options {language=Ruby;output=AST;}
+      a : INT ID^ ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(abc 34)'
+  end
+  
+  example "leaving out tokens using the `!' operator" do
+    result = parse( <<-'END', :a, 'abc 34 dag 4532' )
+      grammar Bang;
+      options {language=Ruby;output=AST;}
+      a : ID INT! ID! INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    
+    result.should == 'abc 4532'
+  end
+  
+  example "tokens in `(...)?' optional subrule" do
+    result = parse( <<-'END', :a, 'a 1 b' )
+      grammar OptionalThenRoot;
+      options {language=Ruby;output=AST;}
+      a : ( ID INT )? ID^ ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(b a 1)'
+  end
+  
+  example "labeled literal-string root token" do
+    result = parse( <<-'END', :a, 'void foo;' )
+      grammar LabeledStringRoot;
+      options {language=Ruby;output=AST;}
+      a : v='void'^ ID ';' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(void foo ;)'
+  end
+  
+  example 'rule with token wildcard' do
+    result = parse( <<-'END', :a, 'void foo;' )
+      grammar Wildcard;
+      options {language=Ruby;output=AST;}
+      a : v='void'^ . ';' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(void foo ;)'
+  end
+  
+  example "token wildcard as root via the `^' operator" do
+    result = parse( <<-'END', :a, 'void foo;' )
+      grammar WildcardRoot;
+      options {language=Ruby;output=AST;}
+      a : v='void' .^ ';' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(foo void ;)'
+  end
+  
+  example "labeled token wildcard as root via the `^' operator" do
+    result = parse( <<-'END', :a, 'void foo;' )
+      grammar WildcardRootWithLabel;
+      options {language=Ruby;output=AST;}
+      a : v='void' x=.^ ';' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(foo void ;)'
+  end
+  
+  
+  example "token wildcard as root (with list label)" do
+    result = parse( <<-'END', :a, 'void foo;' )
+      grammar WildcardRootWithListLabel;
+      options {language=Ruby;output=AST;}
+      a : v='void' x=.^ ';' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(foo void ;)'
+  end
+  
+  example "trashed token wildcard" do
+    result = parse( <<-'END', :a, 'void foo;' )
+      grammar WildcardBangWithListLabel;
+      options {language=Ruby;output=AST;}
+      a : v='void' x=.! ';' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == 'void ;'
+  end
+  
+  example "multiple occurences of the `^' operator in a list of tokens" do
+    result = parse( <<-'END', :a, 'a 34 c' )
+      grammar RootRoot;
+      options {language=Ruby;output=AST;}
+      a : ID^ INT^ ID ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(34 a c)'
+  end
+  
+  example "another case of multiple occurences of the `^' operator" do
+    result = parse( <<-'END', :a, 'a 34 c' )
+      grammar RootRoot2;
+      options {language=Ruby;output=AST;}
+      a : ID INT^ ID^ ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(c (34 a))'
+  end
+  
+  example "root-hoist using `^' from within a (...)+ block" do
+    result = parse( <<-'END', :a, 'a 34 * b 9 * c' )
+      grammar RootThenRootInLoop;
+      options {language=Ruby;output=AST;}
+      a : ID^ (INT '*'^ ID)+ ;
+      ID  : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(* (* (a 34) b 9) c)'
+  end
+  
+  example "nested subrules without any AST ops resulting in a flat list" do
+    result = parse( <<-'END', :a, 'void a b;' )
+      grammar NestedSubrule;
+      options {language=Ruby;output=AST;}
+      a : 'void' (({
+      #do nothing
+      } ID|INT) ID | 'null' ) ';' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == 'void a b ;'
+  end
+  
+  example "invoking another rule without any AST ops, resulting in a flat list" do
+    result = parse( <<-'END', :a, 'int a' )
+      grammar InvokeRule;
+      options {language=Ruby;output=AST;}
+      a  : type ID ;
+      type : {
+        # do nothing
+      }'int' | 'float' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == 'int a'
+  end
+  
+  example "hoisting the results of another rule as root using the `^' operator" do
+    result = parse( <<-'END', :a, 'int a' )
+      grammar InvokeRuleAsRoot;
+      options {language=Ruby;output=AST;}
+      a  : type^ ID ;
+      type : {
+        # do nothing
+      }'int' | 'float' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(int a)'
+  end
+  
+  example "hoisting another rule's true as root using the `^' operator (with a label)" do
+    result = parse( <<-'END', :a, 'int a' )
+      grammar InvokeRuleAsRootWithLabel;
+      options {language=Ruby;output=AST;}
+      a  : x=type^ ID ;
+      type : {
+        # do nothing
+      }'int' | 'float' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(int a)'
+  end
+  
+  example "hoisting another rule's result tree as root using the `^' operator (with a list += label)" do
+    result = parse( <<-'END', :a, 'int a' )
+      grammar InvokeRuleAsRootWithListLabel;
+      options {language=Ruby;output=AST;}
+      a  : x+=type^ ID ;
+      type : {
+        # do nothing
+      }'int' | 'float' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(int a)'
+  end
+  
+  example "root-hoist via `^' within a (...)* loop resulting in a deeply-nested tree" do
+    result = parse( <<-'END', :a, 'a+b+c+d' )
+      grammar RuleRootInLoop;
+      options {language=Ruby;output=AST;}
+      a : ID ('+'^ ID)* ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(+ (+ (+ a b) c) d)'
+  end
+  
+  example "hoisting another rule's result tree as root from within a (...)* loop resulting in a deeply nested tree" do
+    result = parse( <<-'END', :a, 'a+b+c-d' )
+      grammar RuleInvocationRuleRootInLoop;
+      options {language=Ruby;output=AST;}
+      a : ID (op^ ID)* ;
+      op : {
+        # do nothing
+      }'+' | '-' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(- (+ (+ a b) c) d)'
+  end
+  
+  example "using tail recursion to build deeply-nested expression trees" do
+    result = parse( <<-'END', :s, '3 exp 4 exp 5' )
+      grammar TailRecursion;
+      options {language=Ruby;output=AST;}
+      s : a ;
+      a : atom ('exp'^ a)? ;
+      atom : INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(exp 3 (exp 4 5))'
+  end
+  
+  example "simple token node from a token type set" do
+    result = parse( <<-'END', :a, 'abc' )
+      grammar TokenSet;
+      options {language=Ruby; output=AST;}
+      a : ID|INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == 'abc'
+  end
+  
+  example "hoisting a token-type set token as root with `^'" do
+    result = parse( <<-'END', :a, '+abc' )
+      grammar SetRoot;
+      options {language=Ruby;output=AST;}
+      a : ('+' | '-')^ ID ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(+ abc)'
+  end
+  
+  example "hoisting a token-type set token as root with `^' (with a label)" do
+    result = parse( <<-'END', :a, '+abc' )
+      grammar SetRootWithLabel;
+      options {language=Ruby;output=AST;}
+      a : (x=('+' | '-'))^ ID ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '+ abc'
+  end
+  
+  example "hoisting a token-type set token as root from within a (...)* loop" do
+    result = parse( <<-'END', :a, 'a+b-c' )
+      grammar SetAsRuleRootInLoop;
+      options {language=Ruby;output=AST;}
+      a : ID (('+'|'-')^ ID)* ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(- (+ a b) c)'
+  end
+  
+  example "an `~' inverted token-type set element" do
+    result = parse( <<-'END', :a, '34+2' )
+      grammar NotSet;
+      options {language=Ruby;output=AST;}
+      a : ~ID '+' INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '34 + 2'
+  end
+  
+  example "a `~' inverted token-type set in a rule (with a label)" do
+    result = parse( <<-'END', :a, '34+2' )
+      grammar NotSetWithLabel;
+      options {language=Ruby;output=AST;}
+      a : x=~ID '+' INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '34 + 2'
+  end
+  
+  example "a `~' inverted token-type set element in a rule (with a list += label)" do
+    result = parse( <<-'END', :a, '34+2' )
+      grammar NotSetWithListLabel;
+      options {language=Ruby;output=AST;}
+      a : x=~ID '+' INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '34 + 2'
+  end
+  
+  example "a `~' inverted token-type set element hoisted to root via `^'" do
+    result = parse( <<-'END', :a, '34 55' )
+      grammar NotSetRoot;
+      options {language=Ruby;output=AST;}
+      a : ~'+'^ INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(34 55)'
+  end
+  
+  example "hoisting a `~' inverted token-type set to root using `^' (with label)" do
+    result = parse( <<-'END', :a, '34 55' )
+      grammar NotSetRootWithLabel;
+      options {language=Ruby;output=AST;}
+      a   : x=~'+'^ INT ;
+      ID  : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS  : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(34 55)'
+  end
+  
+  example "hoisting a `~' inverted token-type set to root using `^' (with list += label)" do
+    result = parse( <<-'END', :a, '34 55' )
+      grammar NotSetRootWithListLabel;
+      options {language=Ruby;output=AST;}
+      a : x+=~'+'^ INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == '(34 55)'
+  end
+  
+  example "hoisting a `~' inverted token-type set to root from within a (...)* loop" do
+    result = parse( <<-'END', :a, '3+4+5' )
+      grammar NotSetRuleRootInLoop;
+      options {language=Ruby;output=AST;}
+      a : INT (~INT^ INT)* ;
+      blort : '+' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '(+ (+ 3 4) 5)'
+  end
+  
+  example "multiple tokens with the same label in a rule" do
+    result = parse( <<-'END', :a, 'a b' )
+      grammar TokenLabelReuse;
+      options {language=Ruby;output=AST;}
+      a returns [result] : id=ID id=ID {
+        $result = "2nd id=\%s," \% $id.text
+      } ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '2nd id=b,a b'
+  end
+  
+  example "multiple tokens with the same label in a rule (with a `^' root hoist)" do
+    result = parse( <<-'END', :a, 'a b' )
+      grammar TokenLabelReuse2;
+      options {language=Ruby;output=AST;}
+      a returns [result]: id=ID id=ID^ {$result = "2nd id=#{$id.text},"} ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '2nd id=b,(b a)'
+  end
+  
+  example "extra token in a simple declaration" do
+    result, errors = parse( <<-'END', :decl, 'int 34 x=1;', true )
+      grammar ExtraTokenInSimpleDecl;
+      options {language=Ruby;output=AST;}
+      decl : type^ ID '='! INT ';'! ;
+      type : 'int' | 'float' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    errors.should == [ "line 1:4 extraneous input \"34\" expecting ID" ]
+    result.should == '(int x 1)'
+  end
+  
+  example "missing ID in a simple declaration" do
+    result, errors = parse( <<-'END', :decl, 'int =1;', true )
+      grammar MissingIDInSimpleDecl;
+      options {language=Ruby;output=AST;}
+      tokens {EXPR;}
+      decl : type^ ID '='! INT ';'! ;
+      type : 'int' | 'float' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    errors.should == [ "line 1:4 missing ID at \"=\"" ]
+    result.should == '(int <missing ID> 1)'
+  end
+  
+  example "missing token of a token-type set in a simple declaration" do
+    result, errors = parse( <<-'END', :decl, 'x=1;', true )
+      grammar MissingSetInSimpleDecl;
+      options {language=Ruby;output=AST;}
+      tokens {EXPR;}
+      decl : type^ ID '='! INT ';'! ;
+      type : 'int' | 'float' ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    errors.should == [ "line 1:0 mismatched input \"x\" expecting set nil" ]
+    result.should == '(<error: x> x 1)'
+  end
+  
+  example "missing INT token simulated with a `<missing INT>' error node" do
+    result, errors = parse( <<-'END', :a, 'abc', true )
+      grammar MissingTokenGivesErrorNode;
+      options {language=Ruby;output=AST;}
+      a : ID INT ; // follow is EOF
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    errors.should == [ "line 0:-1 missing INT at \"<EOF>\"" ]
+    result.should == 'abc <missing INT>'
+  end
+  
+  example "missing token from invoked rule results in error node with a resync attribute" do
+    result, errors = parse( <<-'END', :a, 'abc', true )
+      grammar MissingTokenGivesErrorNodeInInvokedRule;
+      options {language=Ruby;output=AST;}
+      a : b ;
+      b : ID INT ; // follow should see EOF
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    errors.should == [ "line 0:-1 mismatched input \"<EOF>\" expecting INT" ]
+    result.should == '<mismatched token: <EOF>, resync = abc>'
+  end
+  
+  example "extraneous ID token displays error and is ignored in AST output" do
+    result, errors = parse( <<-'END', :a, 'abc ick 34', true )
+      grammar ExtraTokenGivesErrorNode;
+      options {language=Ruby;output=AST;}
+      a : b c ;
+      b : ID ;
+      c : INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    errors.should == [ "line 1:4 extraneous input \"ick\" expecting INT" ]
+    result.should == 'abc 34'
+  end
+  
+  example "missing ID token simulated with a `<missing ID>' error node" do
+    result, errors = parse( <<-'END', :a, '34', true )
+      grammar MissingFirstTokenGivesErrorNode;
+      options {language=Ruby;output=AST;}
+      a : ID INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    errors.should == [ "line 1:0 missing ID at \"34\"" ]
+    result.should == '<missing ID> 34'
+  end
+  
+  example "another case where a missing ID token is simulated with a `<missing ID>' error node" do
+    result, errors = parse( <<-'END', :a, '34', true )
+      grammar MissingFirstTokenGivesErrorNode2;
+      options {language=Ruby;output=AST;}
+      a : b c ;
+      b : ID ;
+      c : INT ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    errors.should == [ "line 1:0 missing ID at \"34\"" ]
+    result.should == '<missing ID> 34'
+  end
+  
+  example "no viable alternative for rule is represented as a single `<unexpected: ...>' error node" do
+    result, errors = parse( <<-'END', :a, '*', true )
+      grammar NoViableAltGivesErrorNode;
+      options {language=Ruby;output=AST;}
+      a : b | c ;
+      b : ID ;
+      c : INT ;
+      ID : 'a'..'z'+ ;
+      S : '*' ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    errors.should == [ "line 1:0 no viable alternative at input \"*\"" ]
+    result.should == "<unexpected: 0 S[\"*\"] @ line 1 col 0 (0..0), resync = *>"
+  end
+  
+  example "token with a `+=' list label hoisted to root with `^'" do
+    result = parse( <<-'END', :a, 'a' )
+      grammar TokenListLabelRuleRoot;
+      options {language=Ruby;output=AST;}
+      a : id+=ID^ ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == 'a'
+  end
+  
+  example "token with a list `+=' label trashed with `!'" do
+    result = parse( <<-'END', :a, 'a' )
+      grammar TokenListLabelBang;
+      options {language=Ruby;output=AST;}
+      a : id+=ID! ;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == ''
+  end
+  
+  example "using list `+=' labels to collect trees of invoked rules" do
+    result = parse( <<-'END', :a, 'a b' )
+      grammar RuleListLabel;
+      options {language=Ruby;output=AST;}
+      a returns [result]: x+=b x+=b {
+      t = $x[1]
+      $result = "2nd x=#{t.inspect},"
+      };
+      b : ID;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '2nd x=b,a b'
+  end
+  
+  example "using a list `+=' label to collect the trees of invoked rules within a (...)+ block" do
+    result = parse( <<-'END', :a, 'a b' )
+      grammar RuleListLabelRuleRoot;
+      options {language=Ruby;output=AST;}
+      a returns [result] : ( x+=b^ )+ {
+      $result = "x=\%s," \% $x[1].inspect
+      } ;
+      b : ID;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == 'x=(b a),(b a)'
+  end
+  
+  example "trashing the tree of an invoked rule with `!' while collecting the tree with a list `+=' label" do
+    result = parse( <<-'END', :a, 'a b' )
+      grammar RuleListLabelBang;
+      options {language=Ruby;output=AST;}
+      a returns [result] : x+=b! x+=b {
+      $result = "1st x=#{$x[0].inspect},"
+      } ;
+      b : ID;
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == '1st x=a,b'
+  end
+  
+  example "a whole bunch of different elements" do
+    result = parse( <<-'END', :a, 'a b b c c d' )
+      grammar ComplicatedMelange;
+      options {language=Ruby;output=AST;}
+      a : A b=B b=B c+=C c+=C D {s = $D.text} ;
+      A : 'a' ;
+      B : 'b' ;
+      C : 'c' ;
+      D : 'd' ;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+    END
+    result.should == 'a b b c c d'
+  end
+  
+  example "rule return values in addition to AST output" do
+    result = parse( <<-'END', :a, 'abc 34' )
+      grammar ReturnValueWithAST;
+      options {language=Ruby;output=AST;}
+      a returns [result] : ID b { $result = $b.i.to_s + "\n" } ;
+      b returns [i] : INT {$i=$INT.text.to_i};
+      ID : 'a'..'z'+ ;
+      INT : '0'..'9'+;
+      WS : (' '|'\n') {$channel=HIDDEN;} ;
+  
+    END
+    result.should == "34\nabc 34"
+  end
+  
+  example "a (...)+ loop containing a token-type set" do
+    result = parse( <<-'END', :r, 'abc 34 d' )
+      grammar SetLoop;
+      options { language=Ruby;output=AST; }
+      r : (INT|ID)+ ; 
+      ID : 'a'..'z' + ;
+      INT : '0'..'9' +;
+      WS: (' ' | '\n' | '\t')+ {$channel = HIDDEN;};
+    
+    END
+    result.should == 'abc 34 d'
+  end
+  
+end