path: root/grammar/c++/c++.lm

context lookup
	alias list_lang_object
		list<lang_object>

	alias list_declaration_data
		list<declaration_data>

	alias list_declarator_data
		list<declarator_data>

	alias list_int
		list<int>
	
	alias map_list_lang_object
		map<str, list_lang_object>
	
	#
	# Data types for global data.
	#

	# Language objects. 
	struct lang_object
		typeId: int 
		name: str

		# If the object is a typedef, this points to the real object.
		typedefOf: lang_object

		objectMap: map_list_lang_object
		inherited: list_lang_object
		lookupParent: lang_object
		specializationOf: lang_object
	end

	# This structure is used to keep track of information necessary to make a
	# declaration. While parsing a declaration it records the declaration's
	# attributes.
	struct declaration_data
		isTypedef: int
		isFriend: int
		isTemplate: int

		typeObj: lang_object
	end

	struct declarator_data
		qualObj: lang_object
		pdcScope: lang_object
		lookupObj: lang_object
	end

	# Constants for language object types.
	NamespaceType: int
	ClassType: int 
	TemplateClassType: int
	EnumType: int
	IdType: int
	TypedefType: int
	TemplateIdType: int

	#
	# Global data declarations
	#

	# Object stacks.
	curNamespace: list_lang_object
	declNs: list_lang_object
	lookupNs: list_lang_object
	qualNs: list_lang_object
	templateParamNs: list_lang_object

	# Declaration, declarator data.
	declarationData: list_declaration_data
	declaratorData: list_declarator_data 

	# Template declarations
	templDecl: list_int

	# Root namespace object
	rootNamespace: lang_object

	#
	# Identifier lookup.
	#

	# Lookup the token in the members of an object.
	lang_object lookupInObject( obj: lang_object, name: str )
	{
		# LOG print( '  looking in ', obj->name, '\n' )

		ol: list_lang_object = obj->objectMap->find( name )
		if ol {
			# LOG print( '  * found an object: ', ol.head, '\n' )
			return ol->head
		}

		return nil
	}

	# Lookup in an object and all the objects beneath it in the inheritance
	# tree.
	lang_object lookupWithInheritance( obj: lang_object, name: str )
	{
		found: lang_object = lookupInObject( obj, name )
		if found
			return found

		for inh: lang_object in obj->inherited {
			# First check if the inherited object is the one we are after.
			if inh->name == name && inh->typeId == ClassType {
				# LOG print( '  * found a class name\n' )
				return inh
			}

			# Otherwise look inside the inherited object.
			found = lookupWithInheritance( inh, name )
			if found
				return found
		}

		return nil
	}

	lang_object unqualifiedLookup( name: str )
	{
		found: lang_object

		# Start with the objects in the templateParamNs.
		for Obj: lang_object in rev_list_iter( templateParamNs ) {
			found = lookupWithInheritance( Obj, name )
			if found
				break
		}

		if !found {
			# Iterator over the objects starting at the head of the lookup stack
			# and going up through the lookup parents.
			lookupIn: lang_object = lookupNs->tail
			while lookupIn {
				found = lookupWithInheritance( lookupIn, name )
				if found
					break
				lookupIn = lookupIn->lookupParent
			}
		}

		return found
	}

	# The C++ scanner.
	lex
		rl fract_const / digit* '.' digit+ | digit+ '.' /
		rl exponent / [eE] [+\-]? digit+ /
		rl float_suffix / [flFL] /

		# Single and double literals.
		token TK_SingleLit /( 'L'? "'" ( [^'\\\n] | '\\' any )* "'" )/
		token TK_DoubleLit /( 'L'? '"' ( [^"\\\n] | '\\' any )* '"' )/

		literal `extern `namespace `friend `typedef `auto `register
				`static `mutable `inline `virtual `explicit `const
				`volatile `restrict `class `struct `union `template
				`private `protected `public `using `void `char
				`wchar_t `bool `int `float `double `short `long
				`signed `unsigned `enum `new `delete `operator
				`typename `export `throw `try `catch `sizeof
				`dynamic_cast `static_cast `reinterpret_cast `const_cast
				`typeid `this `true `false `switch `case `default
				`if `else `while `do `for `break `continue
				`return `goto

		# Extensions
		literal `__typeof `__is_pod `__is_empty

		literal `{ `} `; `, `= `( `) `: `& `* `[ `] `~ `+ `-
			`/ `< `> `| `^ `% `! `? `.

		literal `:: `== `!= `&& `|| `*= `/= `%= `+= `-= `&=
			`^= `|= `++ `-- `-> `->* `.* `... `<<= `>>=

		# Token translation targets.
		def unknown_id [lookup_id]
		def class_id [lookup_id]
		def namespace_id [lookup_id]
		def templ_class_id [lookup_id]
		def enum_id [lookup_id]
		def typedef_id [lookup_id]
		def identifier [lookup_id]
		def template_id [lookup_id]

		# Identifiers
		token lookup_id 
			obj: lang_object
			qualObj: lang_object

			/( [a-zA-Z_] [a-zA-Z0-9_]* )/
			{
				name: str = match_text
				found: lang_object = nil
				qualObj: lang_object = nil
				if qualNs->tail {
					# LOG print( 'qualified lookup of ', name, '\n' )

					# Transfer the qualification to the token and reset it.
					qualObj = qualNs->tail
					qualNs->pop_tail()
					qualNs->push_tail( nil )

					# Lookup using the qualification. 
					found = lookupWithInheritance( qualObj, name )
				}
				else {
					# No qualification, full search.
					# LOG print( 'unqualified lookup of ', name, '\n' )
					found = unqualifiedLookup( name )
				}

				# If no match, return an Unknown ID
				id: int = typeid<unknown_id>
				if found
					id = found->typeId

				LookupId: lookup_id = make_token( typeid<lookup_id>,
						input->pull(match_length) )
				LookupId.obj = found
				LookupId.qualObj = qualObj

				input->push( make_tree( id, LookupId ) )
			}

		# Floats.
		token TK_Float /( fract_const exponent? float_suffix? |
			digit+ exponent float_suffix? )/

		# Integer decimal. Leading part buffered by float.
		token TK_IntegerDecimal /( ( '0' | [1-9] [0-9]* ) [ulUL]{0,3} )/

		# Integer octal. Leading part buffered by float.
		token TK_IntegerOctal /( '0' [0-9]+ [ulUL]{0,2} )/

		# Integer hex. Leading 0 buffered by float.
		token TK_IntegerHex /( '0x' [0-9a-fA-F]+ [ulUL]{0,2} )/

		# Preprocessor line.
		ignore /'#' [^\n]* '\n'/

		# Comments and whitespace.
		ignore /( '/*' (any | '\n')* :>> '*/' )/
		ignore /( '//' any* :> '\n' )/
		ignore /( any - 33..126 )+/
	end

	#
	# Support functions
	#

		typeId: int 
		name: str

		# If the object is a typedef, this points to the real object.
		typedefOf: lang_object

		objectMap: map_list_lang_object
		inherited: list_lang_object
		lookupParent: lang_object
		specializationOf: lang_object

	lang_object createLangObject( typeId: int, name: str, lookupParent: lang_object )
	{
		Obj: lang_object = new lang_object()

		Obj->typeId = typeId 
		Obj->name = name
		Obj->typedefOf = nil
		Obj->objectMap = new map_list_lang_object()
		Obj->inherited = new list_lang_object()
		Obj->lookupParent = lookupParent

		return Obj
	}

	# Building the language object tree.
	int insertObject( definedIn: lang_object, name: str, obj: lang_object )
	{
		ol: list_lang_object = definedIn->objectMap->find( name )
		if !ol {
			# Element not in the map already
			ol = new list_lang_object()
			definedIn->objectMap->insert( name, ol )
		}
		ol->push_tail( obj )
	}

	lang_object findClass( inObj: lang_object, lang_objectname: str )
	{
		List: list_lang_object = inObj->objectMap->find( name )
		if List { 
			for obj: lang_object in List {
				if obj->typeId == ClassType {
					return obj
				}
			}
		}
		return nil
	}

	lang_object findTemplateClass( inObj: lang_object, name: str )
	{
		List: list_lang_object = inObj->objectMap->find( name )
		if List { 
			for obj: lang_object in List {
				if obj->typeId == TemplateClassType
					return obj
			}
		}
		return nil
	}

	def root_qual_opt 
		[]
	|	[`::]

	def nested_name_specifier_opt 
		[nested_name_specifier_opt qualifying_name `:: designated_qualifying_name `::]
	|	[nested_name_specifier_opt qualifying_name `::]
	|	[]

	def nested_name_specifier 
		[nested_name_specifier designated_qualifying_name `::]
	|	[nested_name_specifier qualifying_name `::]
	|	[qualifying_name `::]

	def qualifying_name 
		[class_name]
		{
			qualNs->pop_tail()
			qualNs->push_tail( r1.lookupId.obj )
		}

	|	[namespace_id]
		{
			match r1 [Id: lookup_id]
			qualNs->pop_tail()
			qualNs->push_tail( Id.obj )
		}

	|	[typedef_id]
		{
			match r1 [Id: lookup_id]
			qualNs->pop_tail()
			qualNs->push_tail( Id.obj->typedefOf )
		}

	def designated_qualifying_name 
		[`template any_id]
		{
			# FIXME: nulling qualNs is not the right thing to do here.
			qualNs->pop_tail()
			qualNs->push_tail( nil )
		}

	|	[`template any_id 
			templ_arg_open template_argument_list_opt templ_arg_close]
		{
			# FIXME: nulling qualNs is not the right thing to do here.
			qualNs->pop_tail()
			qualNs->push_tail( nil )
		}

	#
	# Id Expression
	#

	def id_expression 
		lookupId: lookup_id 

		[root_qual_opt nested_name_specifier_opt unknown_id]
		{
			lhs.lookupId = lookup_id in r3
		}

	|	[root_qual_opt nested_name_specifier_opt identifier]
		{
			lhs.lookupId = lookup_id in r3
		}

	|	[root_qual_opt nested_name_specifier_opt operator_function_id]
		{
			# Normally the token translation transfers the qualification. Since
			# the operator_function_id does not end in a lookup we must do it ourselves.
			qualObj: lang_object = qualNs->pop_tail()
			qualNs->push_tail( nil )

			lhs.lookupId = construct lookup_id ["x"]
			lhs.lookupId.data = '<operator_function_id>'
			lhs.lookupId.qualObj = qualObj
		}

	|	[root_qual_opt nested_name_specifier_opt conversion_function_id]
		{
			# Normally the token translation transfers the qualification. Since
			# the operator_function_id does not } in a lookup we must do it ourselves.
			qualObj: lang_object = qualNs->pop_tail()
			qualNs->push_tail( nil )

			# Do we need qual reset here becauase operator_function_id does not do it?
			lhs.lookupId = construct lookup_id ["x"]
			lhs.lookupId.data = '<conversion_function_id>'
			lhs.lookupId.qualObj = qualObj
		}

	|	[root_qual_opt nested_name_specifier_opt `~ class_name]
		{
			lhs.lookupId = r4.lookupId
		}

	|	[root_qual_opt nested_name_specifier_opt template_name]
		{
			lhs.lookupId = r3.lookupId
		}
			
	def template_name 
		lookupId: lookup_id 

		[template_id templ_arg_open template_argument_list_opt templ_arg_close]
		{
			lhs.lookupId = lookup_id in r1
		}

	|	[template_id]
		{
			lhs.lookupId = lookup_id in r1
		}


	#
	# Class Names
	#

	def class_name 
		lookupId: lookup_id

		[class_id]
		{
			lhs.lookupId = lookup_id in r1
		}

	|	[templ_class_id]
		{
			lhs.lookupId = lookup_id in r1
		}

	|	[templ_class_id templ_arg_open template_argument_list_opt templ_arg_close]
		{
			# TODO: Look for a specialization.
			lhs.lookupId = lookup_id in r1
		}

	def templ_arg_open 
		[`<]
		{
			qualNs->push_tail( nil )
		}

	def templ_arg_close
		[`>]
		{
			qualNs->pop_tail()
		}

	def declaration 
		[block_declaration] commit
	|	[function_definition] commit
	|	[template_declaration] commit
	|	[explicit_instantiation] commit
	|	[explicit_specialization] commit
	|	[linkage_specification] commit
	|	[namespace_definition] commit

	#
	# Declarations
	#

	def block_declaration 
		[simple_declaration]
	|	[using_declaration]
	|	[using_directive]

	def simple_declaration 
		[declaration_start simple_declaration_forms declaration_end `;]

	# Ordering is important for optimization. The form with the optional
	# decl_specifier_sing should go second.
	def simple_declaration_forms
		[decl_specifier_mult_seq_opt decl_specifier_sing 
			decl_specifier_mult_seq_opt init_declarator_list_opt]

	|	[decl_specifier_mult_seq_opt init_declarator_list_opt]

	def declaration_start 
		[]
		{
			# LOG print( 'opening new declaration_data with templDecl: ', templDecl.tail, '\n' )
			DD: declaration_data = new declaration_data()
			DD->isTypedef = 0
			DD->isFriend = 0
			DD->isTemplate = 0
			declarationData->push_tail( DD )

			# Transfer the template flag and reset it.
			declarationData->tail->isTemplate = templDecl->tail
			templDecl->push_tail( 0 )
		}

	def declaration_end 
		[]
		{
			# LOG print( 'closing declaration_data\n' )
			declarationData->pop_tail()
			templDecl->pop_tail()
		}

	def decl_specifier_sing 
		[type_specifier_sing]
		{
			# Store the object type of the declaration (if any) for use
			# by typedefs. 
			declarationData->tail->typeObj = r1.lookupId.obj
		}

	def type_specifier_seq
		lookupId: lookup_id

		[type_specifier_mult_seq_opt type_specifier_sing type_specifier_mult_seq_opt]
		{
			lhs.lookupId = r2.lookupId
		}

	def type_specifier_sing
		lookupId: lookup_id 

		[simple_type_specifier]
		{
			lhs.lookupId = r1.lookupId
		}
			
	|	[class_specifier]
		{
			lhs.lookupId = construct lookup_id ["x"]
			lhs.lookupId.data = '<class_specifier>'
		}

	|	[enum_specifier]
		{
			lhs.lookupId = construct lookup_id ["x"]
			lhs.lookupId.data = '<enum_specifier>'
		}

	|	[elaborated_type_specifier]
		{
			lhs.lookupId = construct lookup_id ["x"]
			lhs.lookupId.data = '<elaborated_type_specifier>'
		}

	# Type specifier sequence without enum specifier or class specifier.
	def necs_type_specifier_seq
		[type_specifier_mult_seq_opt necs_type_specifier_sing type_specifier_mult_seq_opt]

	# Type specifier singular without enum specifier or class specifier.
	def necs_type_specifier_sing 
		[simple_type_specifier]
	|	[elaborated_type_specifier]

	def type_specifier_mult_seq_opt 
		[type_specifier_mult_seq_opt type_specifier_mult]
	|	[]

	def type_specifier_mult_seq 
		[type_specifier_mult_seq type_specifier_mult]
	|	[type_specifier_mult]

	def simple_type_specifier
		lookupId: lookup_id 

		[simple_type_specifier_name]
		{
			lhs.lookupId = r1.lookupId
		}

	|	[simple_type_specifier_kw_seq]
		{
			lhs.lookupId = construct lookup_id ["x"]
			lhs.lookupId.data = '<simple_type_specifier_kw_seq>'
		}

	|	[`typename root_qual_opt nested_name_specifier type_name]
		{
			lhs.lookupId = r4.lookupId
		}

	|	[`typename root_qual_opt nested_name_specifier identifier]
		{
			lhs.lookupId = lookup_id in r4
		}

	|	[`typename root_qual_opt nested_name_specifier unknown_id]
		{
			lhs.lookupId = lookup_id in r4
		}

		# Extension.
	|	[`__typeof `( expression `)]
		{
			lhs.lookupId = construct lookup_id ["x"]
			lhs.lookupId.data = '<simple_type_specifier_kw_seq>'
		}

	def simple_type_specifier_name
		lookupId: lookup_id 

		[qual_type_name]
		{
			lhs.lookupId = r1.lookupId
		}

	def simple_type_specifier_kw_seq 
		[simple_type_specifier_kw_seq simple_type_specifier_kw]
	|	[simple_type_specifier_kw]

	def simple_type_specifier_kw 
		[`void]
	|	[`char]
	|	[`wchar_t]
	|	[`bool]
	|	[`int]
	|	[`float]
	|	[`double]
	|	[`short]
	|	[`long]
	|	[`signed]
	|	[`unsigned]

	def qual_type_name
		lookupId: lookup_id 

		[root_qual_opt nested_name_specifier_opt type_name]
		{
			lhs.lookupId = r3.lookupId
		}

	def type_name
		lookupId: lookup_id

		[class_name]
		{
			lhs.lookupId = r1.lookupId
		}

	|	[enum_id]
		{
			lhs.lookupId = lookup_id in r1
		}

	|	[typedef_id]
		{
			lhs.lookupId = lookup_id in r1
		}

	# NOTE: the typename case is moved to simple type specifier
	# to take advantage of its conflict resolution.
	def elaborated_type_specifier
		[class_key nested_name_specifier_opt class_head_name]
		{
			Id: lookup_id = lookup_id in r3
			name: str = Id.data

			# Get the ns the class is declared in.
			parentObj: lang_object = declNs->tail
			if Id.qualObj
				parentObj = Id.qualObj

			# Look for the class in the given scope.
			declaredClass: lang_object = findClass( parentObj, name )
			if !declaredClass
				declaredClass = findTemplateClass( parentObj, name )

			if !declaredClass {
				# LOG print( 'creating new class: ', name, '\n' )

				# Class does not exist in the parent scope, create it.
				nsType: int = declaredClassType()

				declaredClass = createLangObject( nsType, name, lookupNs->tail )

				# FIXME: handle friends. Make the class visible only if we are NOT
				# in a friend declaration.  The new class object is necessary to
				# properly process the body of the class.
				if declarationData->tail->isFriend == 0
					insertObject( parentObj, name, declaredClass )
			}
		}

		# TODO: Lookup type specialization.
	|	[class_key nested_name_specifier_opt templ_class_id
			templ_arg_open template_argument_list_opt templ_arg_close]

	|	[`enum nested_name_specifier_opt enum_head_name]
		{
			# TODO: should look for existing enums of the same name.
			Id: lookup_id = lookup_id in r3
			# LOG print( 'creating enumeration ' Id.data '\n' )
			enum: lang_object = createLangObject( EnumType, Id.data, lookupNs->tail )
			insertObject( declNs->tail, Id.data, enum )
		}

	def decl_specifier_mult_seq_opt 
		[decl_specifier_mult_seq_opt decl_specifier_mult]
	|	[]

	def decl_specifier_mult_seq 
		[decl_specifier_mult_seq decl_specifier_mult]
	|	[decl_specifier_mult]

	def decl_specifier_mult 
		[type_specifier_mult]
	|	[storage_class_specifier]
	|	[function_specifier]

	|	[`friend]
		{
			declarationData->tail->isFriend = 1
		}

	|	[`typedef]
		{
			declarationData->tail->isTypedef = 1
		}

	def storage_class_specifier 
		[`auto]
	|	[`register]
	|	[`static]
	|	[`extern]
	|	[`mutable]

	def function_specifier 
		[`inline]
	|	[`virtual]
	|	[`explicit]

	def type_specifier_mult 
		[cv_qualifier]

	def cv_qualifier 
		[`const]
	|	[`volatile]
	|	[`restrict]

	def cv_qualifier_rep 
		[cv_qualifier_rep cv_qualifier]
	|	[]

	def namespace_definition 
		[named_namespace_definition]
	|	[unnamed_namespace_definition]

	def named_namespace_definition
		[original_namespace_definition]
	|	[extension_namespace_definition]

	#
	# Enumerations
	#

	def enum_specifier 
		[`enum nested_name_specifier_opt 
				enum_head_name `{ enumerator_list_opt `}]
		{
			# TODO: should look for existing enums of the same name.
			Id: lookup_id = lookup_id in r3
			# LOG print( 'creating enumeration ' Id.data '\n' )
			enum: lang_object = createLangObject( EnumType, Id.data, lookupNs->tail )
			insertObject( declNs->tail, Id.data, enum )
		}

	|	[`enum `{ enumerator_list_opt `}]

	def enum_head_name
		[class_id] 
	|	[templ_class_id]
	|	[namespace_id]
	|	[typedef_id]
	|	[enum_id]
	|	[identifier]
	|	[template_id]
	|	[unknown_id]

	def enumerator_list_opt 
		[enumerator_list]
	|	[enumerator_list `,]
	|	[]

	def enumerator_list 
		[enumerator_list `, enumerator_definition]
	|	[enumerator_definition]

	def enumerator_definition 
		[enumerator_id]
		{
			Id: lookup_id = lookup_id in r1
			enumId: lang_object = createLangObject( IdType, Id.data, lookupNs->tail )
			insertObject( declNs->tail, Id.data, enumId )
		}

	|	[enumerator_id `= constant_expression]
		{
			Id: lookup_id = lookup_id in r1
			enumId: lang_object = createLangObject( IdType, Id.data, lookupNs->tail )
			insertObject( declNs->tail, Id.data, enumId )
		}

	def enumerator_id
		[namespace_id] 
	|	[typedef_id]
	|	[enum_id]
	|	[class_id] 
	|	[templ_class_id]
	|	[template_id]
	|	[identifier]
	|	[unknown_id]

	#
	# Declarators
	#

	def init_declarator_list_opt 
		[init_declarator_list]
	|	[]

	def init_declarator_list
		[init_declarator_list `, init_declarator]
	|	[init_declarator]

	def init_declarator
		[declarator initializer_opt]

	def initializer_opt
		[`= initializer_clause]
	|	[`( expression `)]
	|	[]

	def initializer_clause 
		[assignment_expression]
	|	[`{ initializer_list `}]
	|	[`{ initializer_list `, `}]
	|	[`{ `}]

	def initializer_list
		[initializer_list `, initializer_clause]
	|	[initializer_clause]

	#
	# Expressions
	#

	def expression 
		[expression `, assignment_expression]
	|	[assignment_expression]

	def expression_opt
		[expression]
	|	[]

	def constant_expression
		[conditional_expression]

	def constant_expression_opt 
		[constant_expression]
	|	[]

	def assignment_expression 
		[conditional_expression]
	|	[logical_or_expression assignment_op assignment_expression]
	|	[throw_expression]

	def assignment_op 
		[`=]
	|	[`*=]
	|	[`/=]
	|	[`%=]
	|	[`+=]
	|	[`-=]
	|	[`>>=]
	|	[`<<=]
	|	[`&=]
	|	[`^=]
	|	[`|=]

	def conditional_expression 
		[logical_or_expression]
	|	[logical_or_expression `? expression `: assignment_expression]

	def logical_or_expression 
		[logical_or_expression `|| logical_and_expression]
	|	[logical_and_expression]

	def logical_and_expression 
		[logical_and_expression `&& inclusive_or_expression]
	|	[inclusive_or_expression]

	def inclusive_or_expression 
		[inclusive_or_expression `| exclusive_or_expression]
	|	[exclusive_or_expression]

	def exclusive_or_expression 
		[exclusive_or_expression `^ and_expression]
	|	[and_expression]

	def and_expression 
		[and_expression `& equality_expression]
	|	[equality_expression]

	def equality_expression 
		[equality_expression `== relational_expression]
	|	[equality_expression `!= relational_expression]
	|	[relational_expression]

	def relational_expression 
		[relational_expression `< shift_expression]
	|	[relational_expression `> shift_expression]
	|	[relational_expression lt_eq shift_expression]
	|	[relational_expression gt_eq shift_expression]
	|	[shift_expression]

	def shift_expression 
		[shift_expression shift_left additive_expression]
	|	[shift_expression shift_right additive_expression]
	|	[additive_expression]

	def additive_expression 
		[additive_expression `+ multiplicative_expression]
	|	[additive_expression `- multiplicative_expression]
	|	[multiplicative_expression]

	def multiplicative_expression 
		[multiplicative_expression `* pm_expression]
	|	[multiplicative_expression `/ pm_expression]
	|	[multiplicative_expression `% pm_expression]
	|	[pm_expression]

	def pm_expression 
		[pm_expression `->* cast_expression]
	|	[pm_expression `.* cast_expression]
	|	[cast_expression]

	def cast_expression 
		[unary_expression]
	|	[`( type_id `) cast_expression]

	def delete_expression 
		[root_qual_opt `delete cast_expression]
	|	[root_qual_opt `delete `[ `] cast_expression]

	def new_initializer_opt 
		[new_initializer]
	|	[]

	def new_initializer 
		[`( expression_opt `)]

	def direct_new_declarator 
		[`[ expression `]]
	|	[direct_new_declarator `[ constant_expression `]]

	def new_declarator_opt 
		[new_declarator]
	|	[]

	def new_declarator 
		[direct_new_declarator]
	|	[ptr_operator_seq direct_new_declarator]
	|	[ptr_operator_seq]

	def new_type_id 
		[necs_type_specifier_seq new_declarator_opt]

	def new_placement 
		[`( expression `)]

	def new_expression 
		[root_qual_opt `new new_type_id new_initializer_opt]
	|	[root_qual_opt `new new_placement new_type_id new_initializer_opt]
	|	[root_qual_opt `new `( type_id `) new_initializer_opt]
	|	[root_qual_opt `new new_placement `( type_id `) new_initializer_opt]

	def unary_operator 
		[`*]
	|	[`&]
	|	[`+]
	|	[`-]
	|	[`!]
	|	[`~]

	def unary_expression 
		[postfix_expression]
	|	[`++ cast_expression]
	|	[`-- cast_expression]
	|	[unary_operator cast_expression]
	|	[`sizeof `( type_id `)]
	|	[`sizeof unary_expression]
	|	[new_expression]
	|	[delete_expression]

	def function_style_type_conv 
		[simple_type_specifier]


	def postfix_expression 
		[primary_expression]
	|	[postfix_expression `[ expression `]]
	|	[postfix_expression `( expression_opt `)]
	|	[function_style_type_conv `( expression_opt `)]
	|	[member_request_expr dot_arrow id_expression]
	|	[member_request_expr dot_arrow pseudo_destructor_call]
	|	[postfix_expression `++]
	|	[postfix_expression `--]
	|	[`dynamic_cast templ_arg_open type_id templ_arg_close `( expression `)]
	|	[`static_cast templ_arg_open type_id templ_arg_close `( expression `)]
	|	[`reinterpret_cast templ_arg_open type_id templ_arg_close `( expression `)]
	|	[`const_cast templ_arg_open type_id templ_arg_close `( expression `)]
	|	[`typeid `( expression `)]
	|	[`typeid `( type_id `)]

	def pseudo_destructor_call
		[root_qual_opt nested_name_specifier_opt `~ pdc_type_name]

	def primary_expression
		[expr_lit]
	|	[`this]
	|	[`( expression `)]
	|	[id_expression]
	# GNU extensions
	|	[`( `{ statement_rep `} `)]
	|	[`__is_pod `( type_id `)]
	|	[`__is_empty `( type_id `)]

	def expr_lit 
		[TK_IntegerDecimal]
	|	[TK_IntegerOctal]
	|	[TK_IntegerHex]
	|	[TK_SingleLit]
	|	[TK_Float]
	|	[double_lit_list]
	|	[`true]
	|	[`false]

	def double_lit_list 
		[TK_DoubleLit double_lit_list]
	|	[TK_DoubleLit]

	def member_request_expr 
		[postfix_expression]
	#	{
	#		# FIXME: If no proper type is found, we must fail.
	#		# LOG print( 'setting member request scope\n' )
	#		# qualNs.set( $1->type != 0 ? $1->type->getObject() : 0 );
	#	}

	def dot_arrow 
		[`->]
	|	[`.]

	def pdc_type_name 
		[enum_id]
	|	[typedef_id]

	#
	# Statements
	#

	def statement_rep 
		[statement_rep statement]
	|	[]

	def statement 
		[declaration_statement]
	|	[labeled_statement]
	|	[expression_statement]
	|	[compound_statement]
	|	[selection_statement]
	|	[iteration_statement]
	|	[jump_statement]
	|	[try_block]

	def labeled_statement 
		[label_id `: statement]
	|	[`case constant_expression `: statement]
	|	[`default `: statement]

	def label_id 
		[unknown_id]
	|	[identifier]
	|	[class_id]
	|	[templ_class_id]
	|	[namespace_id]
	|	[typedef_id]
	|	[enum_id]
	|	[template_id]

	def compound_statement
		[`{ compound_begin statement_rep compound_end `}]

	def compound_begin 
		[]
		{
			newCompound: lang_object = createLangObject( 0,
					'<compound_begin>', lookupNs->tail )
			lookupNs->push_tail( newCompound )

			declNs->push_tail( newCompound )
			# LOG print( 'opening <compound>\n' )
		}

	def compound_end 
		[]
		{
			lookupNs->pop_tail()
			declNs->pop_tail()
			# LOG print( 'closing <compound>\n' )
		}

	def selection_statement 
		[`if `( condition `) statement elseif_clauses else_clause]
	|	[`switch `( condition `) statement]

	def elseif_clauses 
		[elseif_clauses `else `if `( condition `) statement]
	|	[]

	def else_clause 
		[`else statement]
	|	[]

	def iteration_statement
		[`while `( condition `) statement]
	|	[`do statement `while `( expression `) `;]
	|	[`for `( for_init_statement condition_opt `; expression_opt `) statement]

	def jump_statement 
		[`break `;]
	|	[`continue `;]
	|	[`return expression_opt `;]
	|	[`goto any_id `;]

	def any_id
		[unknown_id]
	|	[class_id]
	|	[namespace_id]
	|	[templ_class_id]
	|	[enum_id]
	|	[typedef_id]
	|	[identifier]
	|	[template_id]
		

	def for_init_statement 
		[expression_statement]
	|	[stmt_block_declaration_forms `;]

	def condition 
		[expression]
	|	[type_specifier_seq declarator `= assignment_expression]

	def condition_opt 
		[condition]
	|	[]

	def expression_statement 
		[expression `;]
	|	[`;]

	def declaration_statement 
		[stmt_block_declaration]

	def stmt_block_declaration 
		[declaration_start stmt_block_declaration_forms declaration_end `;]
	|	[using_declaration]
	|	[using_directive]

	def stmt_block_declaration_forms
		[decl_specifier_mult_seq_opt decl_specifier_sing decl_specifier_mult_seq_opt 
			init_declarator_list_opt]
	|	[decl_specifier_mult_seq init_declarator_list_opt]

	#
	# Declarators
	#

	def declarator
		lookupObj: lang_object

		[ptr_operator_seq_opt declarator_id decl_array_or_param_rep declarator_end]
		{
			lhs.lookupObj = r4.lookupObj
		}

	|	[ptr_operator_seq_opt `( sub_declarator `) decl_array_or_param_rep declarator_end]
		{
			lhs.lookupObj = r6.lookupObj
		}

	def sub_declarator 
		[ptr_operator_seq declarator_id decl_array_or_param_rep]
	|	[ptr_operator_seq `( sub_declarator `) decl_array_or_param_rep]
	|	[`( sub_declarator `) decl_array_or_param_rep]
	|	[declarator_id decl_array_or_param_rep]

	def decl_array_or_param_rep 
		[decl_array_or_param_rep decl_array_or_param]
	|	[]

	def decl_array_or_param 
		[`[ constant_expression_opt `]]
	|	[`( parameter_declaration_clause `) cv_qualifier_rep exception_specification_opt]

	def declarator_id
		[declarator_id_forms]
		{
			name: str = r1.lookupId.data
			qualObj: lang_object = r1.lookupId.qualObj

			parentObj: lang_object = declNs->tail
			if qualObj
				parentObj = qualObj

			# Decide if we are declaring a constructor/destructor.
			isConstructor: bool 
			if parentObj == r1.lookupId.obj {
				isConstructor = true
				# LOG print( 'making declarator ' name ' a constructor/destructor\n' )
			}

			if parentObj->specializationOf && 
					parentObj->specializationOf == r1.lookupId.obj
			{
				isConstructor = true
				# LOG print( 'making declarator ' name ' a constructor/destructor\n' )
			}

			obj: lang_object = nil
			if name && !isConstructor && declarationData->tail->isFriend == 0 {
				if declarationData->tail->isTypedef {
					obj = createLangObject( TypedefType, name, lookupNs->tail )
					obj->typedefOf = declarationData->tail->typeObj
					insertObject( parentObj, name, obj )

					# LOG print( 'making declarator ' name ' a typedef\n' )
				}
				else {
					if !qualObj {
						if declarationData->tail->isTemplate {
							# If in a template declaration and the name is not qualified then
							# create the template id.
							obj = createLangObject( TemplateIdType, name, lookupNs->tail )
							#object->objType = declarationData.tail.type
							insertObject( declNs->tail, name, obj )

							# LOG print( 'making declarator ' name ' a template id\n' )
						}
						else {
							obj = createLangObject( IdType, name, lookupNs->tail )
							#object->objType = declarationData.tail().type;
							insertObject( declNs->tail, name, obj )

							# LOG print( 'making declarator ' name ' an id\n' ) 
						}
					}
				}
			}


			DD: declarator_data = new declarator_data()
			DD->qualObj = qualObj
			DD->pdcScope = nil
			DD->lookupObj = lookupNs->tail

			declaratorData->push_tail( DD )

			# If the declarator is qualified, push the qualification to the lookup
			# stack. Also save it in the declarator data so it can be passed to a
			# function body if needed.
			if qualObj {
				lookupNs->push_tail( qualObj )
				declaratorData->tail->lookupObj = qualObj
			}

			# LOG print( 'reduced declarator_id: ' name '\n' )
		}

	# Undoes the setup done by declarator_id and pdc_start.
	def declarator_end
		lookupObj: lang_object

		[]
		{
			# Get the lookupObject from the scope and pass it up. If we are about to
			# parse a function body it will be needed.
			lhs.lookupObj = declaratorData->tail->lookupObj

			pdcScope: lang_object = declaratorData->tail->pdcScope
			qualObj: lang_object = declaratorData->tail->qualObj

			declaratorData->pop_tail()

			if pdcScope {
				# LOG print( 'closing <pdc_scope>\n' )
				lookupNs->pop_tail()
				declNs->pop_tail()
			}

			if qualObj {
				# LOG print( 'popping lookupNs\n' )
				lookupNs->pop_tail()
			}
		}

	def declarator_id_forms
		lookupId: lookup_id 

		[id_expression]
		{
			lhs.lookupId = r1.lookupId
		}

	|	[root_qual_opt nested_name_specifier_opt type_name]
		{
			lhs.lookupId = r3.lookupId
		}

	|	[root_qual_opt nested_name_specifier_opt `~ class_id]
		{
			lhs.lookupId = lookup_id in r4
		}

	|	[root_qual_opt nested_name_specifier_opt `~ templ_class_id]
		{
			lhs.lookupId = lookup_id in r4
		}
	|	[root_qual_opt nested_name_specifier_opt `~ unknown_id]
		{
			lhs.lookupId = lookup_id in r4
		}

	def type_id
		lookupId: lookup_id 

		[type_specifier_seq abstract_declarator_opt]
		{
			lhs.lookupId = r1.lookupId
		}

	def abstract_declarator_opt 
		[abstract_declarator]
	|	[]

	def abstract_declarator
		[ptr_operator_seq abstract_noid abstract_decl_array_or_param_seq_opt declarator_end]
	|	[ptr_operator_seq `( sub_abstract_declarator `) 
			abstract_decl_array_or_param_seq_opt declarator_end]
	|	[abstract_noid abstract_decl_array_or_param_seq declarator_end]
	|	[`( sub_abstract_declarator `) abstract_decl_array_or_param_seq_opt declarator_end]

	def sub_abstract_declarator
		[ptr_operator_seq abstract_noid abstract_decl_array_or_param_seq_opt]

	|	[ptr_operator_seq `( sub_abstract_declarator `) 
			abstract_decl_array_or_param_seq_opt]
		
	|	[`( sub_abstract_declarator `) abstract_decl_array_or_param_seq_opt]

	def abstract_noid 
		[]
		{
			#  Make scope for declarator.
			DD: declarator_data = new declarator_data()
			declaratorData->push_tail( DD )
		}

	def abstract_decl_array_or_param_seq_opt
		[abstract_decl_array_or_param_seq_opt abstract_decl_array_or_param]
	|	[]

	def abstract_decl_array_or_param_seq
		[abstract_decl_array_or_param_seq abstract_decl_array_or_param]
	|	[abstract_decl_array_or_param]

	def abstract_decl_array_or_param
		[`[ constant_expression_opt `]]
	|	[`( parameter_declaration_clause `) cv_qualifier_rep 
			exception_specification_opt]

	def parameter_declaration_clause
		[pdc_start parameter_declaration_list]
	|	[pdc_start parameter_declaration_list `...]
	|	[pdc_start parameter_declaration_list `, `...]
	|	[pdc_start `...]
	|	[pdc_start]

	def pdc_start 
		[]
		{
			if !declaratorData->tail->pdcScope {
				# We are going to need a scope for the declarator.
				pdcScope: lang_object = createLangObject( 0,
						'<pdc_scope>', lookupNs->tail )

				lookupNs->push_tail( pdcScope )
				declNs->push_tail( pdcScope )

				declaratorData->tail->pdcScope = pdcScope
				declaratorData->tail->lookupObj = pdcScope
				# LOG print( 'opening <pdc_scope>\n' )
			}
		}

	def parameter_declaration_list 
		[parameter_declaration_list `, parameter_declaration]
	|	[parameter_declaration]

	def parameter_declaration 
		[declaration_start parameter_declaration_forms declaration_end]

	# Ordering the productions such that decl_specifier_sing is tried first is good
	# for performance.
	def parameter_declaration_forms
		[decl_specifier_mult_seq_opt decl_specifier_sing decl_specifier_mult_seq_opt 
			param_maybe_declarator maybe_parameter_init]

	|	[decl_specifier_mult_seq param_maybe_declarator maybe_parameter_init]

	def param_maybe_declarator 
		[abstract_declarator]
	|	[declarator]
	|	[]

	def maybe_parameter_init 
		[`= constant_expression]
	|	[]

	def ptr_operator 
		[`&]
	|	[root_qual_opt nested_name_specifier_opt `* cv_qualifier_rep]

	def ptr_operator_seq 
		[ptr_operator_seq ptr_operator]
	|	[ptr_operator]

	def ptr_operator_seq_opt 
		[ptr_operator_seq_opt ptr_operator]
	|	[]

	#
	# Functions
	#

	def function_definition
		[function_def_declaration ctor_initializer_opt function_body function_def_end]

	def function_def_declaration
		[declaration_start function_def_declaration_forms declaration_end]

	def function_def_declaration_forms 
		[decl_specifier_mult_seq_opt decl_specifier_sing 
			decl_specifier_mult_seq_opt function_def_declarator]
	|	[decl_specifier_mult_seq function_def_declarator]
	|	[function_def_declarator]

	def function_def_declarator 
		[declarator]
		{
			# The lookupObj from the declarator is the deepest lookup object found
			# while parsing the declarator. Make it visible in the function body.
			# This could be the args, the qualObj, or the parent to the function.
			lookupNs->push_tail( r1.lookupObj )
		}

	def function_def_end 
		[]
		{
			# Pop the lookup object.
			lookupNs->pop_tail()
		}

	def function_body
		[function_body_begin `{ statement_rep function_body_end `}]

	def function_body_begin 
		[]
		{
			newFunctionBody: lang_object = createLangObject( 0,
					'<function_body_begin>', lookupNs->tail )

			lookupNs->push_tail( newFunctionBody )

			declNs->push_tail( newFunctionBody )

			templDecl->push_tail( 0 )
			# LOG print( 'opening <function_body>\n' )
		}

	def function_body_end 
		[]
		{
			# First undoes the function body begin work. Then undoes the setup in
			# function_def_declarator.
			declNs->pop_tail()
			lookupNs->pop_tail()
			templDecl->pop_tail()
			# LOG print( 'closing <function_body>\n' )
		}



	#
	# Classs
	#

	int declaredClassType()
	{
		if declarationData->tail->isTemplate {
			return TemplateClassType
		} else {
			return ClassType
		}
	}

	def class_specifier 
		[class_head base_clause_opt `{ class_member_rep class_body_end `}]
		{
	# FIXME: reparse not implemented yet
	# FIXME FIXME: reparse is actually implemented now implemented
	#		# Visit class function bodies, but skip nested classes.
	#		for CFB: class_function_body in lhs {
	#			skipping class_specifier
	#
	#			# Reparse the text of the class function body as a function body
	#			function_body FB = parse function_body[ $CFB ]
	#
	#			# Replace the class function body with the parsed function body.
	#			CFB = cons class_function_body [FB.tree]
	#		}
		}

	def class_head 
		[class_key]
		{
			nsType: int = declaredClassType()

			# LOG print( 'creating new anonymous class\n' )
			newClass: lang_object = createLangObject( nsType,
					'<anon_class>', lookupNs->tail )

			lookupNs->push_tail( newClass )
			declNs->push_tail( newClass )
		}

	|	[class_key nested_name_specifier_opt class_head_name]
		{
			Id: lookup_id = lookup_id in r3
			name: str = Id.data

			# Get the ns the class is declared in.
			parentObj: lang_object = declNs->tail
			if Id.qualObj
				parentObj = Id.qualObj

			# Look for the class in the given scope.
			declaredClass: lang_object = findClass( parentObj, name )
			if !declaredClass
				declaredClass = findTemplateClass( parentObj, name )

			if !declaredClass {
				# LOG print( 'creating new class: ' name '\n' )

				# Class does not exist in the parent scope, create it.
				nsType: int = declaredClassType()

				declaredClass = createLangObject( nsType, name, lookupNs->tail )

				# FIXME: handle friends. Make the class visible only if we are NOT
				# in a friend declaration.  The new class object is necessary to
				# properly process the body of the class.
				if declarationData->tail->isFriend == 0
					insertObject( parentObj, name, declaredClass )
			}

			# Push the found/new class.
			lookupNs->push_tail( declaredClass )
			declNs->push_tail( declaredClass )
		}

	|	[class_key nested_name_specifier_opt templ_class_id
			templ_arg_open template_argument_list_opt templ_arg_close]
		{
			match r3 [Id: lookup_id]
			id: str = Id.data
			classObj: lang_object = Id.obj

			# TODO: Try to find the specializaition in the template class object.
			# TypeList typeList;
			# makeTypeList( typeList $6->last );

			declaredClass: lang_object
			#declaredClass = classObj->findSpecExact( typeList );
			if !declaredClass {
				# LOG print( 'making new template specialization\n' )
				nsType: int = declaredClassType()
				declaredClass = createLangObject( nsType, id, lookupNs->tail )
				# LOG print( 'declaredClass: ' declaredClass '\n' )
				declaredClass->specializationOf = classObj
				# $$->typeListMapEl = classObj->typeListMap.insert( typeList, declaredClass );
			}

			# Push the found/new class.
			lookupNs->push_tail( declaredClass )
			declNs->push_tail( declaredClass )
		}

	def class_body_end 
		[]
		{
			# Pop the class ns.
			lookupNs->pop_tail()
			declNs->pop_tail()

			# LOG print( 'closing off class\n' )
		}

	def class_head_name
		[class_id]
	|	[templ_class_id]
	|	[namespace_id]
	|	[typedef_id]
	|	[enum_id]
	|	[unknown_id]
	|	[identifier]
	|	[template_id]

	def class_key 
		[`class]
	|	[`struct]
	|	[`union]

	def class_member_rep 
		[class_member_rep class_member]
	|	[]

	def class_member 
		[member_declaration]
	|	[access_specifier `:]

	def member_declaration 
		[declaration_start member_declaration_forms declaration_end `;]
	|	[class_function_definition]
	|	[using_declaration]
	|	[template_declaration]

	def class_function_definition
		[function_def_declaration ctor_initializer_opt class_function_body function_def_end]

	lex
		token cfb_open /'{'/
		token cfb_close /'}'/
		token cfb_string /
					"'" ( [^'\\\n] | '\\' any )* "'" |
					'"' ( [^"\\\n] | '\\' any )* '"'/
		token cfb_comment /
					( '/*' (any | '\n')* :>> '*/' ) |
					( '//' any* :> '\n' )/
		token cfb_data /[^{}'"/]+ | '/'/
	end

	def cfb_item
		[cfb_data]
	|	[cfb_string]
	|	[cfb_comment]
	|	[cfb_open cfb_item* cfb_close]

	def cfb_conts
		[cfb_item* cfb_close]



	def class_function_body
	#	['{' cfb_conts]
	#|	[function_body]
		[function_body]

	# Get better performance if the form with decl_specifier_sing comes first.
	def member_declaration_forms
		[decl_specifier_mult_seq_opt decl_specifier_sing 
			decl_specifier_mult_seq_opt member_declarator_list_opt]
	|	[decl_specifier_mult_seq_opt member_declarator_list_opt]

	def member_declarator_list_opt 
		[member_declarator_list]
	|	[]

	def member_declarator_list 
		[member_declarator_list `, member_declarator]
	|	[member_declarator]

	def member_declarator 
		[declarator]
	|	[declarator `= constant_expression]
	|	[declarator `: constant_expression]
	|	[`: constant_expression]

	def access_specifier 
		[`private]
	|	[`protected]
	|	[`public]

	def access_specifier_opt 
		[access_specifier]
	|	[]

	def using_declaration
		[`using id_expression `;]
		{
			obj: lang_object = r2.lookupId.obj
			if obj
				insertObject( declNs->tail, obj->name, obj )
		}

	|	[`using type_id `;]
		{
			obj: lang_object = r2.lookupId.obj
			if obj
				insertObject( declNs->tail, obj->name, obj )
		}

	def using_directive
		[`using `namespace root_qual_opt nested_name_specifier_opt 
			namespace_id `;]
		{
			# This uses a simple, incomplete guard against cycles in the graph of
			# using namespaces. A more sophisticated and complete guard would look
			# for longer cycles as well. Note that even gcc 3.3.5 does not bother.
			match r5 [Id: lookup_id]
			usingObject: lang_object = Id.obj
			inObject: lang_object = declNs->tail
			if usingObject != inObject
				inObject->inherited->push_tail( usingObject )
		}


	#
	# Derived classes
	#

	def base_clause_opt 
		[base_clause]
	|	[]

	def base_clause 
		[`: base_specifier_list]

	def base_specifier_list 
		[base_specifier_list `, base_specifier]
	|	[base_specifier]

	int addBaseSpecifier( inObject: lang_object, inheritedObject: lang_object )
	{
		# Resolve typedefs.
		if inheritedObject->typeId == TypedefType
			inheritedObject = inheritedObject->typedefOf

		inObject->inherited->push_tail( inheritedObject )
	}

	def base_specifier 
		[root_qual_opt nested_name_specifier_opt type_name]
		{
			addBaseSpecifier( declNs->tail, r3.lookupId.obj )
		}

	|	[`virtual access_specifier_opt root_qual_opt nested_name_specifier_opt type_name]
		{
			addBaseSpecifier( declNs->tail, r5.lookupId.obj )
		}

	|	[access_specifier virtual_opt root_qual_opt nested_name_specifier_opt type_name]
		{
			addBaseSpecifier( declNs->tail, r5.lookupId.obj )
		}

	def virtual_opt 
		[`virtual]
	|	[]

	#
	# Special member functions
	#

	def conversion_function_id 
		[`operator conversion_type_id]

	def conversion_type_id 
		[necs_type_specifier_seq ptr_operator_seq_opt]

	def ctor_initializer_opt 
		[ctor_initializer]
	|	[]

	def ctor_initializer
		[`: mem_initializer_list]

	def mem_initializer_list 
		[mem_initializer_list `, mem_initializer]
	|	[mem_initializer]

	def mem_initializer 
		[mem_initializer_id `( expression_opt `)]

	def mem_initializer_id 
		[root_qual_opt nested_name_specifier_opt unknown_id]
	|	[root_qual_opt nested_name_specifier_opt identifier]
	|	[root_qual_opt nested_name_specifier_opt type_name]
	|	[root_qual_opt nested_name_specifier_opt template_name]


	#
	# Overloading
	#
	def operator_function_id 
		[`operator operator]

	def operator 
		[`+] | [`-] | [`*] | [`/] | [`=] | [`<] | [`>] | [`&] | [`|] |
		[`^] | [`%] | [`~] |	[`!] | [`( `)] | [`[ `]] | [`new] |
		[`delete] | [`->] | [`++] | [`--] | [`*=] | [`/=] | [`%=] |
		[`+=] | [`-=] | [`>>=] | [`<<=] | [`&=] | [`^=] | [`|=] | [`==] |
		[`!=] | [`&&] | [`||] | [lt_eq] | [gt_eq] | [shift_left] | [shift_right]

	def lt_eq 
		[`< `=]
	#	try {
	#		if ( $2->leader != 0 ) {
	#			#ifdef LOG_REDUCE
	#			cerr << "rejecting less-than equals-to" << endl;
	#			#endif
	#			reject();
	#		}
	#	};

	def gt_eq 
		[`> `=]
	#	try {
	#		if ( $2->leader != 0 ) {
	#			#ifdef LOG_REDUCE
	#			cerr << "rejecting greater-than equals-to" << endl;
	#			#endif
	#			reject();
	#		}
	#	};

	def shift_left 
		[`< `<]
	#	try {
	#		if ( $2->leader != 0 ) {
	#			#ifdef LOG_REDUCE
	#			cerr << "rejecting shift left" << endl;
	#			#endif
	#			reject();
	#		}
	#	};

	def shift_right 
		[`> `>]
	#	try {
	#		if ( $2->leader != 0 ) {
	#			#ifdef LOG_REDUCE
	#			cerr << "rejecting shift right" << endl;
	#			#endif
	#			reject();
	#		}
	#	};

	#
	# Templates
	#

	def template_declaration 
		[template_declaration_params declaration]
		{
			templDecl->pop_tail()
			templateParamNs->pop_tail()
		}

	def template_declaration_params
		[`template `< tpl_start template_parameter_list `>]
		{
			templDecl->push_tail( 1 )
		}

	|	[`export `template `< tpl_start template_parameter_list `>]
		{
			templDecl->push_tail( 1 )
		}

	def tpl_start 
		[]
		{
			# Create a new scope for the template parameters.
			newTemplateParamScope: lang_object = 
				createLangObject( 0, '<tpl_start>', lookupNs->tail )

			templateParamNs->push_tail( newTemplateParamScope )
		}

	def template_parameter_list 
		[template_parameter_list `, template_parameter]
	|	[template_parameter]

	def template_parameter 
		[type_parameter]
	|	[template_parameter_declaration]

	def template_parameter_declaration
		[declaration_start template_parameter_declaration_forms declaration_end]

	def template_parameter_declaration_forms
		[decl_specifier_mult_seq param_maybe_declarator maybe_parameter_init]

	|	[temp_param_decl_specifier_sing decl_specifier_mult_seq_opt 
			param_maybe_declarator maybe_parameter_init]

	|	[decl_specifier_mult_seq temp_param_decl_specifier_sing 
			decl_specifier_mult_seq_opt param_maybe_declarator maybe_parameter_init]

	def temp_param_decl_specifier_sing 
		[temp_param_type_specifier_sing]

	# Template parameters cannot support elaborated type specifer or class specifier.
	def temp_param_type_specifier_sing 
		[templ_simple_type_specifier]
	|	[enum_specifier]

	def templ_simple_type_specifier 
		[simple_type_specifier_name]
	|	[simple_type_specifier_kw_seq]

	def type_parameter
		[`class type_param_id type_param_init_opt]
		{
			Id: lookup_id = lookup_id in r2
			if Id {
				# The lookup ns should be a template param scope.
				newClass: lang_object = 
					createLangObject( ClassType, Id.data, lookupNs->tail )
				insertObject( templateParamNs->tail, Id.data, newClass )
			}
		}

	|	[`typename type_param_id type_param_init_opt]
		{
			Id: lookup_id = lookup_id in r2
			if Id {
				# The lookup ns should be a template param scope.
				newClass: lang_object = 
					createLangObject( ClassType, Id.data, lookupNs->tail )
				insertObject( templateParamNs->tail, Id.data, newClass )
			}
		}

	|	[`template `< tpl_start template_parameter_list `>
				`class type_param_id templ_type_param_init_opt]
		{
			Id: lookup_id = lookup_id in r7
			if Id {
				newClass: lang_object = 
					createLangObject( TemplateClassType, Id.data, lookupNs->tail )
				insertObject( templateParamNs->tail, Id.data, newClass )
			}
		}

	def templ_type_param_init_opt 
		[`= id_expression]
	|	[]

	def type_param_init_opt 
		[`= type_id]
	|	[]

	def type_param_id 
		[namespace_id]
	|	[typedef_id]
	|	[enum_id]
	|	[class_id] 
	|	[templ_class_id]
	|	[identifier]
	|	[template_id]
	|	[unknown_id]
	|	[] 

	def template_argument_list_opt 
		[template_argument_list]
	|	[]

	def template_argument_list 
		[template_argument_list `, template_argument]
	|	[template_argument]

	def template_argument 
		[type_id]
	|	[assignment_expression]

	def explicit_instantiation 
		[`template declaration]
	|	[declaration_start decl_specifier_mult_seq `template declaration declaration_end]

	def explicit_specialization 
		[`template `< `> declaration]

	## Not sure what this one is about?
	#explicit_specialization: 
	#	declaration_start decl_specifier_mult_seq KW_Template '<' '>' 
	#	declaration declaration_end;


	#
	# Original namespace definition
	#

	def original_namespace_definition
		[orig_namespace_def_name `{ declaration* namespace_end `}]

	def orig_namespace_def_name [`namespace unknown_id]
		{
			match r2 [Id: lookup_id]
			nspace: lang_object = createLangObject(
					NamespaceType, Id.data, lookupNs->tail )

			# Insert the new object into the dictionary of the parent.
			insertObject( curNamespace->tail, Id.data, nspace )

			# Push the namespace 
			curNamespace->push_tail( nspace )
			declNs->push_tail( nspace )
			lookupNs->push_tail( nspace )

			# LOG print( 'created original namespace: ' Id.data '\n' )
		}

	def namespace_end []
		{
			# Pop the namespace.
			curNamespace->pop_tail()
			declNs->pop_tail()
			lookupNs->pop_tail()

			# LOG print( 'closed namespace\n' )
		}

	#
	# Extension namespace definition
	#

	def extension_namespace_definition
		[ext_namespace_def_name `{ declaration* namespace_end `}]

	def ext_namespace_def_name [`namespace namespace_id]
		{
			match r2 [Id: lookup_id]
			nspace: lang_object = Id.obj

			# Push the namespace 
			curNamespace->push_tail( nspace )
			declNs->push_tail( nspace )
			lookupNs->push_tail( nspace )

			# LOG print( 'found extended namespace: ' Id.data '\n' )
		}

	#
	# Unnamed namespace definition
	#
	def unnamed_namespace_definition
		[unnamed_namespace_def_name `{ declaration* namespace_end `}]

	def unnamed_namespace_def_name [`namespace]
		{
			nspace: lang_object = createLangObject(
					NamespaceType, '<unnamed_namespace>',
					lookupNs->tail )

			# Push the namespace 
			curNamespace->push_tail( nspace )
			declNs->push_tail( nspace )
			lookupNs->push_tail( nspace )

			# LOG print( 'parsed unnamed namespace\n' )
		}

	#
	# linkage_specification
	#
	def linkage_specification 
		[`extern TK_DoubleLit `{ declaration* `}]
	|	[`extern TK_DoubleLit declaration]

	#
	# Exception Handling.
	#

	def try_block 
		[`try compound_statement handler_seq]

	def handler_seq 
		[handler_seq handler]
	|	[handler]

	def handler 
		[`catch `( exception_declaration `) compound_statement]

	def exception_declaration 
		[type_specifier_seq declarator]
	|	[type_specifier_seq abstract_declarator]
	|	[type_specifier_seq]
	|	[`...]

	def throw_expression 
		[`throw assignment_expression]
	|	[`throw]

	def exception_specification_opt 
		[exception_specification]
	|	[]

	def exception_specification 
		[`throw `( type_id_list_opt `)]

	def type_id_list_opt 
		[type_id_list]
	|	[]

	def type_id_list 
		[type_id_list `, type_id]
	|	[type_id]

	def start
		[declaration*]

	#
	# Grammar done.
	#

	int printObject( indent: str, obj: lang_object )
	{
		print( indent, obj->name )
		
		if obj->objectMap->length > 0
			print( ' {\n' )
		
		Map: map_list_lang_object = obj->objectMap
		for List: list_lang_object in Map  {
			List2: list_lang_object = List
			for Obj: lang_object in List2 {
				printObject( indent + '  ', Obj )
			}
		}


		if obj->objectMap->length > 0
			print( indent, '}' )

		print( '\n' )
	}

end # lookup

#
# Global data declarations
#

Lookup: lookup = new lookup()

# Constants for language object types.
Lookup->NamespaceType = typeid<lookup::namespace_id>
Lookup->ClassType = typeid<lookup::class_id>
Lookup->TemplateClassType = typeid<lookup::templ_class_id>
Lookup->EnumType = typeid<lookup::enum_id>
Lookup->IdType = typeid<lookup::identifier>
Lookup->TypedefType = typeid<lookup::typedef_id>
Lookup->TemplateIdType = typeid<lookup::template_id>


# Object stacks.
Lookup->curNamespace = new lookup::list_lang_object()
Lookup->declNs = new lookup::list_lang_object()
Lookup->lookupNs = new lookup::list_lang_object()
Lookup->qualNs = new lookup::list_lang_object()
Lookup->templateParamNs = new lookup::list_lang_object()

# Declaration, declarator data.
Lookup->declarationData = new lookup::list_declaration_data()
Lookup->declaratorData = new lookup::list_declarator_data()

# Template declarations
Lookup->templDecl = new lookup::list_int()

# Root namespace object
Lookup->rootNamespace = lookup::createLangObject( Lookup->NamespaceType, '<root_namespace>', nil )

# Initialize the namespace and declaration stacks with the root namespace
Lookup->curNamespace->push_tail( Lookup->rootNamespace )
Lookup->declNs->push_tail( Lookup->rootNamespace )
Lookup->lookupNs->push_tail( Lookup->rootNamespace )

# Start with no qualification (note variables are initialized to zero)
Lookup->qualNs->push_tail( nil )

Lookup->templDecl->push_tail( 0 )

DD: lookup::declaration_data = new lookup::declaration_data()
DD->isTypedef = 0
DD->isFriend = 0
DD->isTemplate = 0
Lookup->declarationData->push_tail( DD )

parse S: lookup::start( Lookup )[ stdin ]
if ! S {
	print( error )
	exit( 1 )
}

print( '***** NAMSPACES *****\n' )
lookup::printObject( '', Lookup->rootNamespace )
print( '***** UNKNOWN DECLARATORS *****\n' )
for DI: lookup::declarator_id in S {
	if match DI 
		[lookup::root_qual_opt lookup::nested_name_specifier_opt lookup::`~ UID: lookup::unknown_id]
	{
		print( UID, '\n' )
	}
}