path: root/frontend/syntax.icl

implementation module syntax

import StdEnv, compare_constructor

import RWSDebug

import scanner, general, Heap, typeproperties, utilities

::	Ident =
	{ 	id_name		:: !String
	,	id_info 	:: !SymbolPtr
	}

instance toString Ident
where toString {id_name} = id_name

instance toString (Import from_symbol)
where toString {import_module} = toString import_module


/*	Each Identifier is equipped with a pointer to a SymbolTableEntry that is
	used for binding the identifier with its definition.
*/

::	SymbolTable			:== Heap SymbolTableEntry
::	SymbolPtr 			:== Ptr SymbolTableEntry

::	SymbolTableEntry = 
	{	ste_kind		:: !STE_Kind
	,	ste_index		:: !Index
	,	ste_def_level	:: !Level
	,	ste_previous	:: SymbolTableEntry
	}

::	STE_BoundTypeVariable	= { stv_count :: !Int, stv_attribute :: !TypeAttribute, stv_info_ptr :: !TypeVarInfoPtr}

::	STE_Kind	= STE_FunctionOrMacro ![Index]
				| STE_Type
				| STE_Constructor
				| STE_Selector ![Global Index]
				| STE_Field !Ident
				| STE_Class
				| STE_Member
				| STE_Instance
				| STE_Variable !VarInfoPtr
				| STE_TypeVariable !TypeVarInfoPtr
				| STE_TypeAttribute !AttrVarInfoPtr
				| STE_BoundTypeVariable !STE_BoundTypeVariable
				| STE_Imported !STE_Kind !Index
				| STE_DclFunction
				| STE_Module !(Module (CollectedDefinitions ClassInstance IndexRange))
				| STE_OpenModule !Int !(Module (CollectedDefinitions ClassInstance IndexRange))
				| STE_ClosedModule
				| STE_LockedModule
				| STE_Empty 
				| STE_DictType !CheckedTypeDef
				| STE_DictCons !ConsDef
				| STE_DictField !SelectorDef
				| STE_Called ![Index] /* used during macro expansion to indicate that this function is called */

::	Global object =
	{	glob_object	:: !object
	,	glob_module	:: !Index
	}
	
::	Module defs = 
	{	mod_name		:: !Ident
	,	mod_type		:: !ModuleKind
	, 	mod_imports		:: ![ParsedImport]
	,	mod_imported_objects :: ![ImportedObject]
	,	mod_defs		:: !defs
	}

::	ParsedModule	:== Module  [ParsedDefinition]
::	ScannedModule 	:== Module  (CollectedDefinitions (ParsedInstance FunDef) IndexRange)

	
::	ModuleKind	= MK_Main | MK_Module | MK_System | MK_None

::	RhsDefsOfType	= ConsList ![ParsedConstructor]
					| SelectorList !Ident ![ATypeVar] ![ParsedSelector]
					| TypeSpec !AType
					| EmptyRhs !BITVECT


::	CollectedDefinitions instance_kind macro_defs =
	{	def_types 			:: ![TypeDef TypeRhs]
	,	def_constructors	:: ![ConsDef]
	,	def_selectors		:: ![SelectorDef]
	,	def_macros			:: !macro_defs
	,	def_classes			:: ![ClassDef]
	,	def_members			:: ![MemberDef]
	,	def_funtypes		:: ![FunType]
	,	def_instances		:: ![instance_kind]
	}

::	LocalDefs = LocalParsedDefs [ParsedDefinition] | CollectedLocalDefs CollectedLocalDefs

::	IndexRange	= { ir_from :: !Index, ir_to :: !Index }

::  Index	:== Int
NoIndex		:== -1


::  Level	:== Int
NotALevel 	:==  -1

::	CollectedLocalDefs =
	{	loc_functions	:: !IndexRange
	,	loc_nodes		:: ![(Optional SymbolType, NodeDef ParsedExpr)]
	}

::	NodeDef dst =
	{	nd_dst		::!dst,
		nd_alts		::!OptGuardedAlts,
		nd_locals	::!LocalDefs
	}

::	Rhs =
	{	rhs_alts	:: !OptGuardedAlts
	,	rhs_locals	:: !LocalDefs
	}

cIsAFunction	:== True
cIsNotAFunction :== False

::	ParsedDefinition 
	=	PD_Function  Position Ident Bool [ParsedExpr] Rhs FunKind
	|	PD_NodeDef  Position ParsedExpr Rhs
	|	PD_Type ParsedTypeDef
	|	PD_TypeSpec Position Ident Priority (Optional SymbolType) Specials
	|	PD_Class ClassDef [ParsedDefinition]
	|	PD_Instance (ParsedInstance ParsedDefinition)
	|	PD_Instances [ParsedInstance ParsedDefinition]
	|	PD_Import [ParsedImport]
	|	PD_ImportedObjects [ImportedObject]
	|	PD_Erroneous

::	FunKind	= FK_Function !Bool | FK_Macro | FK_Caf | FK_Unknown
cNameNotLocationDependent :== False
cNameLocationDependent :== True

::	ParsedSelector =
	{	ps_field_name		:: !Ident
	,	ps_selector_name	:: !Ident
	,	ps_field_type		:: !AType
	,	ps_field_var		:: !Ident
	,	ps_field_pos		:: !Position
	}

::	ParsedConstructor =
	{	pc_cons_name 	:: !Ident
	,	pc_cons_arity	:: !Int
	,	pc_exi_vars		:: ![ATypeVar]
	,	pc_arg_types	:: ![AType]
	,	pc_cons_prio	:: !Priority
	,	pc_cons_pos		:: !Position
	}
	
::	ParsedInstance member =
	{	pi_class 	:: !Ident
	,	pi_ident	:: !Ident
	,	pi_types	:: ![Type]
	,	pi_context	:: ![TypeContext]
	,	pi_pos		:: !Position
	,	pi_members	:: ![member]
	,	pi_specials	:: !Specials
	}


::	Specials
	= SP_ParsedSubstitutions 	![Env Type TypeVar]
	| SP_Substitutions 		 	![SpecialSubstitution]
	| SP_ContextTypes			![Special]
	| SP_FunIndex				!Index
	| SP_TypeOffset				!Int
	| SP_None

::	SpecialSubstitution =
	{	ss_environ	:: !Env Type TypeVar
	,	ss_context	:: ![TypeContext]
	,	ss_vars		:: ![TypeVar]
	,	ss_attrs	:: ![AttributeVar]
	}

::	Special =
	{	spec_index	:: !Global Index
	,	spec_types	:: ![[Type]]
	,	spec_vars	:: ![TypeVar]
	, 	spec_attrs	:: ![AttributeVar]
	}


::	AttrInequality =
	{	ai_demanded :: !AttributeVar
	,	ai_offered	:: !AttributeVar
	}

::	DefinedSymbol = 
	{	ds_ident		:: !Ident
	,	ds_arity		:: !Int
	,	ds_index		:: !Index
	}

::	ClassSymbIdent =
	{	cs_name		:: !Ident
	,	cs_arity 	:: !Int
	,	cs_index 	:: !Int
	}

::	ClassDef =
 	{	class_name			:: !Ident
	,	class_arity			:: !Int
	,	class_args			:: ![TypeVar]
	,	class_context		:: ![TypeContext]
	,	class_members		:: !{# DefinedSymbol}
	,	class_dictionary	:: !DefinedSymbol
	,	class_pos			:: !Position
	,	class_cons_vars		:: !BITVECT
	}

::	MemberDef =
	{	me_symb			:: !Ident
	,	me_class		:: !Global Index
	,	me_offset		:: !Index
	,	me_type			:: !SymbolType
	,	me_type_ptr		:: !VarInfoPtr
	,	me_class_vars	:: ![TypeVar]
	,	me_pos			:: !Position
	,	me_priority 	:: !Priority
	}


::	InstanceType =
	{	it_vars			:: [TypeVar]
	,	it_types		:: ![Type]
	,	it_attr_vars	:: [AttributeVar]
	,	it_context		:: ![TypeContext]
	}

::	ClassInstance =
 	{	ins_class		:: !Global DefinedSymbol
	,	ins_ident		:: !Ident
	,	ins_type		:: !InstanceType
	,	ins_members		:: !{# DefinedSymbol}
	,	ins_specials	:: !Specials
	,	ins_pos			:: !Position
	}

::	Import from_symbol =
	{	import_module		:: !Ident
	,	import_symbols		:: ![from_symbol]
	,	import_file_position:: !(!FileName, !Int)	// for error messages
	}

::	ParsedImport		:== Import ImportDeclaration

::	ImportedIdent =
	{	ii_ident	:: !Ident
	,	ii_extended	:: !Bool
	}

::	ImportDeclaration	= ID_Function !ImportedIdent
						| ID_Class !ImportedIdent !(Optional [ImportedIdent])
						| ID_Type !ImportedIdent !(Optional [ImportedIdent])
						| ID_Record !ImportedIdent !(Optional [ImportedIdent])
						| ID_Instance !ImportedIdent !Ident !(![Type],![TypeContext])

// MW2 moved some type definitions

cIsImportedLibrary :== True
cIsImportedObject :== False
:: ImportedObject =
	{	io_is_library :: !Bool
	,	io_name    :: !{#Char}
	}

::	RecordType =
	{	rt_constructor	:: !DefinedSymbol
	,	rt_fields		:: !{# FieldSymbol}
	}
	
::	FieldSymbol =
	{	fs_name			:: !Ident
	,	fs_var			:: !Ident
	,	fs_index		:: !Index
	}


::	TypeRhs	= AlgType ![DefinedSymbol]
			| SynType !AType
			| RecordType !RecordType
			| AbstractType !BITVECT
			| UnknownType

::	ParsedTypeDef :== TypeDef RhsDefsOfType
::	CheckedTypeDef :== TypeDef TypeRhs

cAllBitsClear			:== 0

cIsHyperStrict			:== 1
cIsNonCoercible			:== 2
cMayBeNonCoercible		:== 4

::	TypeDef type_rhs =
 	{	td_name			:: !Ident
	,	td_index		:: !Int
	,	td_arity		:: !Int
	,	td_args			:: ![ATypeVar]
	,	td_attrs		:: ![AttributeVar]
	,	td_context		:: ![TypeContext]
	,	td_rhs			:: !type_rhs
	,	td_attribute	:: !TypeAttribute
	,	td_pos			:: !Position
	}

::	FunType =
	{	ft_symb			:: !Ident
	,	ft_arity		:: !Int
	,	ft_priority		:: !Priority
	,	ft_type			:: !SymbolType
	,	ft_pos			:: !Position
	,	ft_specials		:: !Specials
	,	ft_type_ptr		:: !VarInfoPtr
	}

::	FreeVar =
	{	fv_def_level	:: !Level
	,	fv_name			:: !Ident
	,	fv_info_ptr		:: !VarInfoPtr
	,	fv_count		:: !Int
	}
	
::	FunCall =
	{	fc_level		:: !Level
	,	fc_index		:: !Index
	}

::	FunInfo =
	{	fi_calls			:: ![FunCall]
	,	fi_group_index		:: !Index
	,	fi_def_level		:: !Level
	,	fi_free_vars		:: ![FreeVar]
	,	fi_local_vars		:: ![FreeVar]
	,	fi_dynamics			:: ![ExprInfoPtr]
	,	fi_is_macro_fun		:: !Bool // whether the function is a local function of a macro
	}

::	ParsedBody =
	{	pb_args	:: ![ParsedExpr]
	,	pb_rhs	:: !Rhs
	}

::	CheckedBody =
	{	cb_args			:: ![FreeVar]
	,	cb_rhs			:: ![Expression]
	}

::	TransformedBody =
	{	tb_args			:: ![FreeVar]
	,	tb_rhs			:: !Expression
	}

::	FunctionBody	= ParsedBody ![ParsedBody]
					| CheckedBody !CheckedBody
	/* The next three constructors are used during macro expansion (module transform) */
					| PartioningMacro
					| PartioningFunction !CheckedBody !Int
					| RhsMacroBody !CheckedBody
	/* macro expansion the transforms a CheckedBody into a TransformedBody */
					| TransformedBody !TransformedBody
					| Expanding ![FreeVar] // the parameters of the newly generated function
					| BackendBody ![BackendBody]
					| NoBody
					
::	BackendBody =
	{	bb_args	:: ![FunctionPattern]
	,	bb_rhs	:: !Expression
	}

::	FunDef =
	{	fun_symb		:: !Ident
	,	fun_arity		:: !Int
	,	fun_priority	:: !Priority
	,	fun_body		:: !FunctionBody
	,	fun_type		:: !Optional SymbolType
	,	fun_pos			:: !Position
	,	fun_index		:: !Int
	,	fun_kind		:: !FunKind
	,	fun_lifted		:: !Int
//	,	fun_type_ptr	:: !TypeVarInfoPtr
	,	fun_info		:: !FunInfo
	}

cIsAGlobalVar	:== True
cIsALocalVar	:== False

::	ConsClasses =
	{	cc_size			::!Int
	,	cc_args			::![ConsClass]	// the lists have the
	,	cc_linear_bits	::![Bool]		// same length
	}
					
::	ConsClass	:== Int

::	OptionalVariable :== Optional (Bind Ident VarInfoPtr)

:: 	AuxiliaryPattern
		= AP_Algebraic !(Global DefinedSymbol) !Index [AuxiliaryPattern] OptionalVariable
		| AP_Variable !Ident !VarInfoPtr OptionalVariable
		| AP_Basic !BasicValue OptionalVariable
		| AP_Dynamic !AuxiliaryPattern !DynamicType !OptionalVariable
		| AP_Constant !AP_Kind !(Global DefinedSymbol) !Priority
		| AP_WildCard !OptionalVariable
		| AP_Empty !Ident

:: AP_Kind = APK_Constructor !Index | APK_Macro

::	VarInfo  =	VI_Empty | VI_Type !AType | VI_Occurrence !Occurrence | VI_UsedVar !Ident |
				VI_Expression !Expression | VI_Variable !Ident !VarInfoPtr | VI_LiftedVariable !VarInfoPtr |
				VI_Count !Int /* the reference count of a variable */ !Bool /* true if the variable is global, false otherwise */ |
				VI_AccVar !ConsClass !ArgumentPosition /* used during fusion to determine accumulating parameters of functions */ |
				VI_Alias !BoundVar /* used for resolving aliases just before type checking (in transform) */ |
				 /* used during elimination and lifting of cases */
				VI_FreeVar !Ident !VarInfoPtr !Int !AType | VI_BoundVar !AType | VI_LocalVar |
				VI_ClassVar !Ident !VarInfoPtr !Int | /* to hold dictionary variables during overloading */
				VI_ForwardClassVar !VarInfoPtr | /* to hold the dictionary variable generated during overloading */
				VI_Forward !BoundVar | VI_LetVar !LetVarInfo | VI_LetExpression !LetExpressionInfo | VI_CaseVar !VarInfoPtr |
				VI_CorrespondenceNumber !Int | /* it is assumed that this alternative is _only_ used in module comparedefimp */
				VI_SequenceNumber !Int |
				VI_Used | /* for indicating that an imported function has been used */
				VI_PropagationType !SymbolType | /* for storing the type with propagation environment of an imported function */
				VI_ExpandedType !SymbolType | /* for storing the (expanded) type of an imported function */
				VI_Record ![AuxiliaryPattern] |
				VI_Pattern !AuxiliaryPattern |
				VI_Default !Int | VI_Indirection !Int | /* used during conversion of dynamics; the Int indiacted the refenrence count */
				VI_Body !SymbIdent !TransformedBody ![FreeVar] | /* used during fusion */
				VI_Dictionary !SymbIdent ![Expression] !Type | /* used during fusion */
				VI_Extended !ExtendedVarInfo !VarInfo |
				VI_Defined /* for marking type code variables during overloading */ | VI_LocallyDefined

::	ExtendedVarInfo = EVI_VarType !AType

::	ArgumentPosition :== Int

::	VarInfoPtr	:== Ptr VarInfo

::	LetVarInfo =
	{	lvi_count		:: !Int
	,	lvi_depth		:: !Int
	,	lvi_new			:: !Bool
	,	lvi_var			:: !Ident
	,	lvi_expression	:: !Expression	
	,   lvi_previous	:: ![PreviousLetVarInfo]
	}

::	PreviousLetVarInfo =
	{	plvi_count		:: !Int
	,	plvi_depth		:: !Int
	,	plvi_new		:: !Bool
	}

::	LetExpressionStatus	= LES_Untouched | LES_Moved | LES_Updated !Expression

::	LetExpressionInfo =
	{	lei_count			:: !Int
	,	lei_depth			:: !Int 
	,	lei_var				:: !FreeVar 
	,   lei_expression		:: !Expression
	,   lei_status			:: !LetExpressionStatus
	,   lei_type			:: !AType
	}

cNotVarNumber :== -1

::	BoundVar = 
	{	var_name		:: !Ident
	,	var_info_ptr	:: !VarInfoPtr
	,	var_expr_ptr	:: !ExprInfoPtr
	}

::	TypeSymbIdent =
	{	type_name		:: !Ident
	,	type_arity		:: !Int
	,	type_index		:: !Global Index
	,	type_prop		:: !TypeSymbProperties
	}

::	TypeSymbProperties =
	{	tsp_sign		:: !SignClassification
	,	tsp_propagation	:: !PropClassification
	,	tsp_coercible	:: !Bool
	}

::	SymbKind	= SK_Unknown
				| SK_Function !(Global Index)
				| SK_OverloadedFunction !(Global Index)
				| SK_Constructor !(Global Index)
				| SK_Macro !(Global Index)
//				| SK_RecordSelector !(Global Index)
				| SK_GeneratedFunction !FunctionInfoPtr !Index
				| SK_TypeCode

// MW2 moved some type definitions

/*	Some auxiliary type definitions used during fusion. Actually, these definitions
	should have beengiven in seperate module. Unfortunately, Clean's module system
	forbids cyclic dependencies between def modules.
	
*/

::	FunctionHeap 	:== Heap FunctionInfo

::	FunctionInfoPtr	:== Ptr FunctionInfo

::	FunctionInfo	= FI_Empty | FI_Function !GeneratedFunction

::	Producer	= PR_Empty
				| PR_Function !SymbIdent !Index
				| PR_Class !App ![BoundVar] !Type
//				| PR_Constructor !SymbIdent ![Expression]
				| PR_GeneratedFunction !SymbIdent !Index
				| PR_Curried !SymbIdent

::	InstanceInfo = II_Empty | II_Node !{! Producer} !FunctionInfoPtr !InstanceInfo !InstanceInfo

::	GeneratedFunction = 
	{	gf_fun_def			:: !FunDef
	,	gf_instance_info	:: !InstanceInfo
	,	gf_cons_args		:: !ConsClasses
	,	gf_fun_index		:: !Index
	}
	
/*	... main type definitions continued .... */

::	ExpressionHeap 	:== Heap ExprInfo

::	ExprInfoPtr		:== Ptr ExprInfo

::	TempLocalVar	:== Int

::	DynamicPtr		:== ExprInfoPtr

::	ExprInfo		= EI_Empty

		/* For handling overloading */

					| EI_Overloaded !OverloadedCall 						/* initial, set by the type checker */
					| EI_Instance 	!(Global DefinedSymbol) ![Expression]	/* intermedediate, used during resolving of overloading */ 
					| EI_Selection 	![Selection] !VarInfoPtr ![Expression]	/* intermedediate, used during resolving of overloading */
					| EI_Context 	![Expression]							/* intermedediate, used during resolving of overloading */

		/* For handling dynamics */

					| EI_Dynamic 				!(Optional DynamicType)
					| EI_DynamicType			!DynamicType ![DynamicPtr]

		/* Auxiliary, was EI_DynamicType before checking */

					| EI_DynamicTypeWithVars	![TypeVar] !DynamicType ![DynamicPtr]				

		/* Auxiliary, used during type checking */

					| EI_TempDynamicType 		!(Optional DynamicType) !AType ![TypeContext] !ExprInfoPtr !SymbIdent
					| EI_TempDynamicPattern 	![TypeVar] !DynamicType ![DynamicPtr] ![TempLocalVar] !AType ![TypeContext] !ExprInfoPtr !SymbIdent
					
					| EI_TypeOfDynamic 			![VarInfoPtr] !TypeCodeExpression				/* Final */
					| EI_TypeOfDynamicPattern 	![VarInfoPtr] !TypeCodeExpression				/* Final */

					| EI_TypeCode 		!TypeCodeExpression
					| EI_TypeCodes 		![TypeCodeExpression]

					| EI_Attribute !Int


		/*	EI_FreeVariables is uded to store the (free) variables occurring in the case expression */

//					| EI_FreeVariables ![UnboundVariable] !ExprInfo

		/* EI_ClassTypes is used to store the instance types of a class These type are used during fusion to generate proper types for 
		   the fusion result (i.e. the resulting function after elimination of dictionaries) */

					| EI_DictionaryType !Type
					| EI_CaseType !CaseType
					| EI_LetType ![AType]
					| EI_CaseTypeAndRefCounts !CaseType !RefCountsInCase
					| EI_LetTypeAndRefCounts ![AType] ![Int]

		/* for converting case into function patterns the following auxiliary constuctors are used */

					| EI_Default !Expression !AType !ExprInfoPtr
					| EI_DefaultFunction !SymbIdent ![Expression]
					| EI_Extended !ExtendedExprInfo !ExprInfo

::	ExtendedExprInfo
					= EEI_ActiveCase !ActiveCaseInfo

::	ActiveCaseInfo =
	{	aci_params					:: ![FreeVar]
	,	aci_opt_unfolder			:: !(Optional SymbIdent)
	,	aci_free_vars				:: !Optional [BoundVar]
	,	aci_linearity_of_patterns	:: ![[Bool]]
	}

::	RefCountsInCase = 
	{	rcc_all_variables		:: ![CountedVariable]
	,	rcc_default_variables	:: ![CountedVariable]
	,	rcc_pattern_variables	:: ![[CountedVariable]]
	}

::	CountedVariable =
	{	cv_variable	:: !VarInfoPtr
	,	cv_count	:: !Int
	}


/*
	OverloadedCall contains (type) information about functions that are overloaded. This structure is built during type checking
	and used after (standard) unification to insert the proper instances of the corresponding functions.

*/

::	OverloadedCall = 
	{	oc_symbol	:: !SymbIdent
	,	oc_context	:: ![TypeContext]
	,	oc_specials	:: ![Special]
	}

/*
	CaseType contains the type information needed to type the corresponding case construct:
		ct_pattern_type : the type of the pattern
		ct_result_type  : the type of the result (of each pattern)
		ct_cons_types   : the types of the arguments of each pattern constructor
*/
		
::	CaseType =
	{	ct_pattern_type	:: !AType
	,	ct_result_type	:: !AType
	,	ct_cons_types 	:: ![[AType]]
	}
		

::	SymbIdent =
	{	symb_name		:: !Ident
	,	symb_kind		:: !SymbKind
	,	symb_arity		:: !Int
	}

::	ConsDef =
	{	cons_symb			:: !Ident
	,	cons_type			:: !SymbolType
	,	cons_arg_vars		:: ![[ATypeVar]]
	,	cons_priority		:: !Priority
	,	cons_index			:: !Index
	,	cons_type_index		:: !Index
	,	cons_exi_vars		:: ![ATypeVar]
//	,	cons_exi_attrs		:: ![AttributeVar]
	,	cons_type_ptr		:: !VarInfoPtr
	,	cons_pos			:: !Position
	}

::	SelectorDef =
	{	sd_symb			:: !Ident
	,	sd_field		:: !Ident
	,	sd_type			:: !SymbolType
	,	sd_exi_vars		:: ![ATypeVar]
//	,	sd_exi_attrs	:: ![AttributeVar]
	,	sd_field_nr		:: !Int
	,	sd_type_index	:: !Int
	,	sd_type_ptr		:: !VarInfoPtr
	,	sd_pos			:: !Position
	}

::	SymbolType =
	{	st_vars			:: ![TypeVar]
	,	st_args			:: ![AType]
	,	st_arity		:: !Int
	,	st_result		:: !AType
	,	st_context		:: ![TypeContext]
	,	st_attr_vars	:: ![AttributeVar]
	,	st_attr_env		:: ![AttrInequality]
	}

::	TypeContext =
	{	tc_class	:: !Global DefinedSymbol
	,	tc_types	:: ![Type]
	,	tc_var		:: !VarInfoPtr
	}

::	AType =
	{	at_attribute	:: !TypeAttribute
	,	at_annotation	:: !Annotation
	,	at_type			:: !Type
	}
	
::	TempAttrId		:== Int
::	TempVarId		:== Int

::	Type	=	TA !TypeSymbIdent ![AType]
			|	(-->) infixr 9 !AType !AType
			|	(:@:) infixl 9 !ConsVariable ![AType]
			|	TB !BasicType

//			|	TFA [ATypeVar] Type

			| 	GTV !TypeVar
			| 	TV !TypeVar
			|	TempV !TempVarId				/* Auxiliary, used during type checking */

			
			|	TQV	TypeVar
			|	TempQV !TempVarId				/* Auxiliary, used during type checking */

			|	TLifted !TypeVar				/* Auxiliary, used during type checking of lifted arguments */
			|	TE

::	ConsVariable = CV 		!TypeVar
				 | TempCV 	!TempVarId
				 | TempQCV 	!TempVarId


::	DynamicType =
	{	dt_uni_vars 	:: ![ATypeVar]
	,	dt_global_vars	:: ![TypeVar]
	,	dt_type			:: !AType
	}

::	KindHeap	:== Heap KindInfo
::	KindInfoPtr	:== Ptr KindInfo

::	KindInfo	= KI_Var !KindInfoPtr
				| KI_Indirection !KindInfo
				| KI_Arrow ![KindInfo]
				| KI_Const
				
				| KI_ConsVar
				
				| KI_VarBind !KindInfoPtr
				| KI_NormVar !Int


::	TypeVarInfo  	= TVI_Empty | TVI_Type !Type | TVI_Forward !TempVarId | TVI_TypeKind !KindInfoPtr
					| TVI_SignClass !Index !SignClassification !TypeVarInfo | TVI_PropClass !Index !PropClassification !TypeVarInfo
					| TVI_Attribute TypeAttribute
					| TVI_CorrespondenceNumber !Int /* auxiliary used in module comparedefimp */
					| TVI_AType !AType /* auxiliary used in module comparedefimp */
					| TVI_Used /* to adminster that this variable is encountered (in checkOpenTypes) */
					| TVI_TypeCode !TypeCodeExpression
					| TVI_FreshTypeVar TypeVar /* auxiliary used during fusion */

::	TypeVarInfoPtr	:== Ptr TypeVarInfo
::	TypeVarHeap 	:== Heap TypeVarInfo

::	AttrVarInfo  	= AVI_Empty | AVI_Attr !TypeAttribute | AVI_Forward !TempAttrId
					| AVI_CorrespondenceNumber !Int /* auxiliary used in module comparedefimp */
::	AttrVarInfoPtr	:== Ptr AttrVarInfo
::	AttrVarHeap 	:== Heap AttrVarInfo

::	TypeHeaps =
	{	th_vars		:: ! .TypeVarHeap
	,	th_attrs	:: ! .AttrVarHeap
	}

::	TypeVar =
	{	tv_name				:: !Ident
	,	tv_info_ptr			:: !TypeVarInfoPtr
	}


::	ATypeVar =
	{	atv_attribute		:: !TypeAttribute
	,	atv_annotation		:: !Annotation
	,	atv_variable		:: !TypeVar
	}

::	TypeAttribute = TA_Unique | TA_Multi | TA_Var !AttributeVar | TA_RootVar AttributeVar | TA_TempVar !Int | TA_TempExVar
				  | TA_Anonymous | TA_None
				  | TA_List !Int !TypeAttribute | TA_Locked !TypeAttribute

::	AttributeVar =
	{	av_name			:: !Ident
	,	av_info_ptr		:: !AttrVarInfoPtr
	}

::	Annotation	=  AN_Strict | AN_None 

::	BasicType	= BT_Int | BT_Char | BT_Real | BT_Bool | BT_Dynamic
				| BT_File | BT_World
				| BT_String !Type /* the internal string type synonym only used to type string denotations */


::	BasicValue	= BVI !String | BVC !String | BVB !Bool | BVR !String | BVS !String


::	TypeKind = KindVar !KindInfoPtr | KindConst | KindArrow !Int

::	Occurrence =
	{	occ_ref_count	:: !ReferenceCount
	,	occ_bind		:: !OccurrenceBinding
	,	occ_observing	:: !Bool
	,	occ_previous 	:: ![ReferenceCount]
	}

::	ReferenceCount = RC_Used !RC_Used | RC_Unused 

::	SelectiveUse = { su_field :: !Int, su_multiply :: ![ExprInfoPtr], su_uniquely :: ![ExprInfoPtr]  }

::	RC_Used = { rcu_multiply :: ![ExprInfoPtr], rcu_selectively :: ![SelectiveUse], rcu_uniquely :: ![ExprInfoPtr] }

::	OccurrenceBinding	= OB_Empty | OB_OpenLet !Expression | OB_LockedLet !Expression
						| OB_Pattern ![(FreeVar, Int)] !OccurrenceBinding
//						| OB_Closed !LetOccurrences | OB_Marked !LetOccurrences

::	TypeDefInfo =
	{	tdi_kinds			:: ![TypeKind]
	,	tdi_properties		:: !BITVECT
	,	tdi_group			:: ![Global Index]
	,	tdi_group_nr		:: !Int
	,	tdi_group_vars		:: ![Int]
	,	tdi_cons_vars		:: ![Int]
	,	tdi_tmp_index		:: !Int
	,	tdi_classification	:: !TypeClassification
	}

::	TypeDefInfos :== {# .{# TypeDefInfo}}

::	OptGuardedAlts	= GuardedAlts ![GuardedExpr] !(Optional ExprWithLocalDefs)
				 	| UnGuardedExpr !ExprWithLocalDefs

::	GuardedExpr =
	{	alt_nodes	:: ![NodeDefWithLocals]
	,	alt_guard	:: !ParsedExpr
	,	alt_expr	:: !OptGuardedAlts
	}

::	ExprWithLocalDefs = 
	{	ewl_nodes	:: ![NodeDefWithLocals]
	,	ewl_expr	:: !ParsedExpr
	,	ewl_locals	:: !LocalDefs
	}

::	NodeDefWithLocals =
	{	ndwl_strict	:: !Bool
	,	ndwl_def	:: !Bind ParsedExpr ParsedExpr
	,	ndwl_locals	:: !LocalDefs
	}


::	CaseAlt =
	{	calt_pattern	:: !ParsedExpr
	,	calt_rhs		:: !Rhs
	}
	
:: LocalDef		:== ParsedDefinition

cUniqueSelection	:== True
cNonUniqueSelection	:== False

:: ParsedExpr	= PE_List ![ParsedExpr]
				| PE_Ident !Ident
				| PE_Basic !BasicValue
				| PE_Bound !BoundExpr
				| PE_Lambda !Ident ![ParsedExpr] !ParsedExpr !Position
				| PE_Tuple ![ParsedExpr]				
				| PE_Record !ParsedExpr !(Optional Ident) ![FieldAssignment]
				| PE_ArrayPattern ![ElemAssignment]
				| PE_UpdateComprehension !ParsedExpr !ParsedExpr !ParsedExpr ![Qualifier]
				| PE_ArrayDenot ![ParsedExpr]
				| PE_Selection !Bool !ParsedExpr ![ParsedSelection]
				| PE_Update !ParsedExpr [ParsedSelection] ParsedExpr
				| PE_Case !Ident !ParsedExpr [CaseAlt]
				| PE_If !Ident !ParsedExpr !ParsedExpr !ParsedExpr
				| PE_Let !Bool !LocalDefs !ParsedExpr
				| PE_Compr !GeneratorKind !ParsedExpr ![Qualifier]
				| PE_Sequ Sequence
				| PE_WildCard
				| PE_Field !ParsedExpr !(Global FieldSymbol) /* Auxiliary, used during checking */

				| PE_ABC_Code ![String] !Bool
				| PE_Any_Code !(CodeBinding Ident) !(CodeBinding Ident) ![String]

				| PE_DynamicPattern !ParsedExpr !DynamicType
				| PE_Dynamic !ParsedExpr !(Optional DynamicType)
				| PE_Empty

::	ParsedSelection	= PS_Record !Ident !(Optional Ident)
					| PS_Array  !ParsedExpr
					| PS_Erroneous


::	GeneratorKind :== Bool

cIsListGenerator 	:== True
cIsArrayGenerator	:== False

:: LineAndColumn = {lc_line :: !Int, lc_column :: !Int}

::	Generator =
	{	gen_kind	:: !GeneratorKind
	,	gen_pattern :: !ParsedExpr
	,	gen_expr	:: !ParsedExpr
	,	gen_position :: !LineAndColumn
	}

::	Qualifier	=
	{	qual_generators	:: ![Generator]
	,	qual_filter		:: !Optional ParsedExpr
	,	qual_position	:: !LineAndColumn
	}

::	Sequence	= SQ_FromThen ParsedExpr ParsedExpr
				| SQ_FromThenTo ParsedExpr ParsedExpr ParsedExpr
				| SQ_From ParsedExpr
				| SQ_FromTo ParsedExpr ParsedExpr

::	BoundExpr	:== Bind ParsedExpr Ident

::	FieldAssignment :== Bind ParsedExpr Ident

::	ElemAssignment :== Bind ParsedExpr [ParsedExpr]

//::	NodeDef :== Bind ParsedExpr ParsedExpr

cIsStrict		:== True
cIsNotStrict	:== False

::	Expression	= Var !BoundVar 
				| App !App
				| (@) infixl 9  !Expression ![Expression]
				| Let !Let
				| Case !Case
				| Selection !(Optional (Global DefinedSymbol)) !Expression ![Selection]
				| Update !Expression ![Selection] Expression
				| RecordUpdate !(Global DefinedSymbol) !Expression ![Bind Expression (Global FieldSymbol)]
				| TupleSelect !DefinedSymbol !Int !Expression
				| Lambda .[FreeVar] !Expression
				| BasicExpr !BasicValue !BasicType
				| WildCard
				| Conditional !Conditional

				| AnyCodeExpr !(CodeBinding BoundVar) !(CodeBinding FreeVar) ![String]
				| ABCCodeExpr ![String] !Bool

				| MatchExpr !(Optional (Global DefinedSymbol)) !(Global DefinedSymbol) !Expression
				| FreeVar FreeVar 
				| Constant !SymbIdent !Int !Priority !Bool	/* auxiliary clause used during checking */
				| ClassVariable !VarInfoPtr					/* auxiliary clause used during overloading */

				| DynamicExpr !DynamicExpr
//				| TypeCase !TypeCase

				| TypeCodeExpression !TypeCodeExpression
				| EE 
				| NoBind ExprInfoPtr /* auxiliary, to store fields that are not specified in a record expression */ 


::	CodeBinding	variable :== Env String variable

::	App =
	{	app_symb 		:: !SymbIdent
	,	app_args 		:: ![Expression]
	,	app_info_ptr	:: !ExprInfoPtr
	}

::	Case =
	{	case_expr		:: !Expression
	,	case_guards		:: !CasePatterns
	,	case_default	:: !Optional Expression
	,	case_ident		:: !Optional Ident
	,	case_info_ptr	:: !ExprInfoPtr
	}

::	Let =
	{	let_strict_binds	:: !Env Expression FreeVar
	,	let_lazy_binds		:: !Env Expression FreeVar
	,	let_expr			:: !Expression
	,	let_info_ptr		:: !ExprInfoPtr
	}

::	DynamicExpr =
	{	dyn_expr		:: !Expression
	,	dyn_opt_type	:: !Optional DynamicType
	,	dyn_info_ptr	:: !ExprInfoPtr
	,	dyn_uni_vars	:: ![VarInfoPtr]			/* filled after type checking */
	,	dyn_type_code	:: !TypeCodeExpression		/* filled after type checking */
	}	

::	CasePatterns = AlgebraicPatterns !(Global Index) ![AlgebraicPattern]
				 | BasicPatterns !BasicType [BasicPattern]
				 | DynamicPatterns [DynamicPattern]						/* auxiliary */
				 | NoPattern											/* auxiliary */


::	Selection	= RecordSelection !(Global DefinedSymbol) !Int
				| ArraySelection !(Global DefinedSymbol) !ExprInfoPtr !Expression
				| DictionarySelection !BoundVar ![Selection] !ExprInfoPtr !Expression

::	TypeCodeExpression = TCE_Empty | TCE_Var !VarInfoPtr /* MV */ | TCE_TypeTerm !VarInfoPtr | TCE_Constructor !Index ![TypeCodeExpression] | TCE_Selector ![Selection] !VarInfoPtr

::	GlobalTCType = GTT_Basic !BasicType	| GTT_Constructor !TypeSymbIdent | GTT_Function

::	FunctionPattern	= FP_Basic !BasicValue !(Optional FreeVar)
					| FP_Algebraic !(Global DefinedSymbol) ![FunctionPattern] !(Optional FreeVar)
					| FP_Variable !FreeVar
					| FP_Dynamic ![VarInfoPtr] !FreeVar !TypeCodeExpression !(Optional FreeVar)
					| FP_Empty

::	AlgebraicPattern =
	{	ap_symbol	:: !(Global DefinedSymbol)
	,	ap_vars		:: ![FreeVar]
	,	ap_expr		:: !Expression
	}
	
::	BasicPattern =
	{	bp_value	:: !BasicValue
	,	bp_expr		:: !Expression
	}

::	TypeCase =
	{	type_case_dynamic	:: !Expression 
	,	type_case_patterns 	:: ![DynamicPattern]
	,	type_case_default	:: !Optional Expression
	,	type_case_info_ptr	:: !ExprInfoPtr
	}
	
::	DynamicPattern =
	{	dp_var					:: !FreeVar
	,	dp_type					:: !ExprInfoPtr
	,	dp_type_patterns_vars	:: ![VarInfoPtr]			/* filled after type checking */
	,	dp_type_code			:: !TypeCodeExpression		/* filled after type checking */
	,	dp_rhs					:: !Expression
	}
	
	
::	Conditional =
	{	if_cond		:: !Expression
	,	if_then		:: !Expression
	,	if_else		:: !Optional Expression
	}

/*
	error handling
*/

:: Position			= FunPos  FileName LineNr FunctName
					| LinePos FileName LineNr
					| PreDefPos Ident
					| NoPos

::	IdentPos =
	{	ip_ident	:: !Ident
	,	ip_line		:: !Int
	,	ip_file		:: !FileName
	}


:: FileName			:== String

:: FunctName		:== String

:: LineNr			:== Int

cNotALineNumber :== -1

/* Used for hashing identifiers */

class needs_brackets a :: a -> Bool

instance == BoundVar
where
	(==) varid1 varid2
		= varid1.var_name == varid2.var_name

instance == Ident
where
	(==) id1 id2
		= id1.id_info == id2.id_info

instance needs_brackets AType
where
	needs_brackets {at_type}
		= needs_brackets at_type

instance needs_brackets Type
where
	needs_brackets (TA {type_arity} _)
		= type_arity > 0
	needs_brackets (_ --> _)
		= True
	needs_brackets (_ :@: _)
		= True
/*	needs_brackets (TFA _ _)
		= True
*/	needs_brackets _
		= False

instance needs_brackets Expression
where
	needs_brackets (App app)
		= app.app_symb.symb_arity > 0
	needs_brackets (_ @ _)
		= True
	needs_brackets (Let _)
		= True
	needs_brackets (Case _)
		= True
	needs_brackets (Lambda _ _)
		= True
	needs_brackets (Selection _ _ _)
		= True
	needs_brackets _
		= False

instance needs_brackets a
where
	needs_brackets _ = False

instance <<< BasicType
where
	(<<<) file BT_Int			= file <<< "Int"
	(<<<) file BT_Char			= file <<< "Char"
	(<<<) file BT_Real			= file <<< "Real"
	(<<<) file BT_Bool			= file <<< "Bool"
/*	(<<<) file (BT_String _)	= file <<< "String" */
	(<<<) file BT_Dynamic		= file <<< "Dynamic"
	(<<<) file BT_File			= file <<< "File"
	(<<<) file BT_World			= file <<< "World"

instance <<< TypeVar
where
	(<<<) file varid = file <<< varid.tv_name 

instance <<< AttributeVar
where
	(<<<) file {av_name,av_info_ptr} = file <<< av_name 

instance toString AttributeVar
where
//	toString {av_name,av_info_ptr} = toString av_name + "[" + toString (ptrToInt av_info_ptr) + "]"
	toString {av_name,av_info_ptr} = toString av_name

instance <<< AType
where
	(<<<) file {at_annotation,at_attribute,at_type}
		= file <<< at_annotation <<< at_attribute <<< at_type

instance <<< TypeAttribute
where
	(<<<) file ta
		= file <<< toString ta

instance toString TypeAttribute
where
	toString (TA_Unique)
		= "* "
	toString (TA_TempVar tav_number)
		= "u" + toString tav_number + ": "
	toString (TA_Var avar)
		= toString avar + ": "
	toString TA_TempExVar
		= "(E)"
	toString (TA_RootVar avar)
		= toString avar + ": "
	toString (TA_Anonymous)
		= ". "
	toString TA_None
		= ""
	toString TA_Multi
		= "o "
	toString (TA_List _ _)
		= "??? "

instance <<< Annotation
where
	(<<<) file an = file <<< toString an

instance toString Annotation
where
	toString AN_Strict	= "!" 
	toString _			= "" 

instance <<< ATypeVar
where
	(<<<) file {atv_annotation,atv_attribute,atv_variable}
		= file <<< atv_annotation <<< atv_attribute <<< atv_variable

instance <<< ConsVariable
where
	(<<<) file (CV tv)
		= file <<< tv
	(<<<) file (TempCV tv)
		= file <<<  "v" <<< tv <<< ' ' 

instance <<< Type
where
	(<<<) file (TV varid)
		= file <<< varid
	(<<<) file (TempV tv_number)
		= file  <<< 'v' <<< tv_number <<< ' ' 
	(<<<) file (TA consid types)
		= file  <<< consid <<< " " <<< types
	(<<<) file (arg_type --> res_type)
		= file <<< arg_type <<< " -> " <<< res_type
	(<<<) file (type :@: types)
		= file <<< type <<< " @" <<< types
	(<<<) file (TB tb)
		= file <<< tb
/*	(<<<) file (TFA vars types)
		= file <<< "A." <<< vars <<< ':' <<< types
*/	(<<<) file (TQV varid)
		= file <<< "E." <<< varid
	(<<<) file (TempQV tv_number)
		= file  <<< "E." <<< tv_number <<< ' ' 
	(<<<) file TE
		= file <<< "### EMPTY ###"
/*
instance <<< [a] | <<< , needs_brackets a
where
	(<<<) file [] 		= file
	(<<<) file [x:xs]
		| needs_brackets x
			= file <<< " (" <<< x <<< ')' <<< xs
			= file <<< ' ' <<< x <<< xs
*/

instance <<< SymbolType
where
	(<<<) file st=:{st_vars,st_attr_vars}
		| st.st_arity == 0
			= write_inequalities st.st_attr_env (write_contexts st.st_context (file <<< '[' <<< st_vars <<< ',' <<< st_attr_vars <<< ']' <<< st.st_result))
			= write_inequalities st.st_attr_env (write_contexts st.st_context (file <<< '[' <<< st_vars <<< ',' <<< st_attr_vars <<< ']' <<< st.st_args <<< " -> " <<< st.st_result))

write_contexts [] file
	= file
write_contexts [tc : tcs] file
	= write_contexts2 tcs (file <<< " | " <<< tc) 
where
	write_contexts2 [] file
		= file
	write_contexts2 [tc : tcs] file
		= write_contexts2 tcs (file <<< " & " <<< tc)

instance <<< AttrInequality
where
	(<<<) file {ai_demanded,ai_offered}
		= file <<< ai_offered <<< " <= " <<< ai_demanded
	
write_inequalities [] file
	= file
write_inequalities [ineq:ineqs] file
	= write_remaining_inequalities ineqs (file <<< ',' <<< ineq)
where
	write_remaining_inequalities [] file
		= file
	write_remaining_inequalities [ineq:ineqs] file
		= write_remaining_inequalities ineqs (file <<< ' ' <<< ineq)

instance <<< TypeContext
where
	(<<<) file co = file <<< co.tc_class <<< " " <<< co.tc_types <<< " <" <<< ptrToInt co.tc_var <<< '>'

instance <<< SymbIdent
where
	(<<<) file symb=:{symb_kind = SK_Function symb_index } = file <<< symb.symb_name <<<  '@' <<< symb_index
	(<<<) file symb=:{symb_kind = SK_GeneratedFunction _ symb_index } = file <<< symb.symb_name <<<  '@' <<< symb_index
	(<<<) file symb=:{symb_kind = SK_OverloadedFunction symb_index } = file <<< symb.symb_name <<<  "[o]@" <<< symb_index
	(<<<) file symb = file <<< symb.symb_name 

instance <<< TypeSymbIdent
where
	(<<<) file symb	= file <<< symb.type_name <<< '.' <<< symb.type_index

instance <<< ClassSymbIdent
where
	(<<<) file symb	= file <<< symb.cs_name 

instance <<< BoundVar
where
	(<<<) file {var_name,var_info_ptr,var_expr_ptr}
		= file <<< var_name <<< '<' <<< ptrToInt var_info_ptr <<< '>'

instance <<< (Bind a b) | <<< a & <<< b 
where
	(<<<) file {bind_src,bind_dst} = file <<< bind_dst <<<  " = " <<< bind_src 


instance <<< AlgebraicPattern
where
	(<<<) file g = file <<< g.ap_symbol <<< g.ap_vars <<< " -> " <<< g.ap_expr

instance <<< BasicPattern
where
	(<<<) file g = file <<< g.bp_value <<< " -> " <<< g.bp_expr

instance <<< CasePatterns
where
	(<<<) file (BasicPatterns type patterns) = file <<< " " <<<patterns
	(<<<) file (AlgebraicPatterns type patterns) = file <<< patterns
	(<<<) file (DynamicPatterns patterns) = file <<< patterns
	(<<<) file NoPattern = file 

instance <<< Qualifier
where
	(<<<) file {qual_generators,qual_filter = Yes qual_filter} = file <<< qual_generators <<< "| " <<< qual_filter
	(<<<) file {qual_generators,qual_filter = No} = file <<< qual_generators

instance <<< Generator
where
	(<<<) file {gen_kind,gen_pattern,gen_expr}
		= file <<< gen_pattern <<< (if gen_kind "<-" "<-:") <<< gen_expr

instance <<< BasicValue
where
	(<<<) file (BVI int)	= file <<< int
	(<<<) file (BVC char)	= file <<< char
	(<<<) file (BVB bool)	= file <<< bool
	(<<<) file (BVR real)	= file <<< real
	(<<<) file (BVS string)	= file <<< string
	
instance <<< Sequence
where
	(<<<) file (SQ_From expr) = file <<< expr
	(<<<) file (SQ_FromTo from_expr to_expr) = file <<< from_expr <<< ".."  <<< to_expr
	(<<<) file (SQ_FromThen from_expr then_expr) = file <<< from_expr  <<< ',' <<< then_expr <<< ".."
	(<<<) file (SQ_FromThenTo from_expr then_expr to_expr) = file <<< from_expr  <<< ',' <<< then_expr <<< ".." <<< to_expr

instance <<< Expression
where
	(<<<) file (Var ident) = file <<< ident
	(<<<) file (App {app_symb, app_args, app_info_ptr})
		= file <<< app_symb <<< ' ' <<< app_args
	(<<<) file (f_exp @ a_exp) = file <<< '(' <<< f_exp <<< " @ " <<< a_exp <<< ')'
	(<<<) file (Let {let_info_ptr, let_strict_binds, let_lazy_binds, let_expr}) 
			= write_binds "" (write_binds "!" (file <<< "let" <<< '\n') let_strict_binds) let_lazy_binds <<< "in\n" <<< let_expr
	where
		write_binds x file []
			= file
		write_binds x file [bind : binds]
			= write_binds x (file <<< x <<< " " <<< bind <<< '\n') binds
 	(<<<) file (Case {case_expr,case_guards,case_default=No})
		= file <<< "case " <<< case_expr <<< " of\n" <<< case_guards
	(<<<) file (Case {case_expr,case_guards,case_default= Yes def_expr})
		= file <<< "case " <<< case_expr <<< " of\n" <<< case_guards <<< "\n\t-> " <<< def_expr
	(<<<) file (BasicExpr basic_value basic_type) = file <<< basic_value
	(<<<) file (Conditional {if_cond,if_then,if_else}) =
			else_part (file <<< "IF " <<< if_cond <<< "\nTHEN\n" <<< if_then) if_else
	where
		else_part file No = file <<< '\n'
		else_part file (Yes else) = file <<< "\nELSE\n" <<< else <<< '\n'

/*	(<<<) file (Conditional {if_cond = {con_positive,con_expression},if_then,if_else}) =
			else_part (file <<< (if con_positive "IF " "IFNOT ") <<< con_expression <<< "\nTHEN\n" <<< if_then) if_else
	where
		else_part file No = file <<< '\n'
		else_part file (Yes else) = file <<< "\nELSE\n" <<< else <<< '\n'
*/
 	(<<<) file (Selection opt_tuple expr selectors) = file <<< expr <<< selector_kind opt_tuple <<< selectors
	where
		selector_kind No		= '.'
		selector_kind (Yes _)	= '!'
	(<<<) file (Update expr1 selections expr2) =  file <<< '{' <<< expr1  <<< " & " <<<  selections <<< " = " <<< expr2 <<< '}'
	(<<<) file (RecordUpdate cons_symbol expression expressions) = file <<< '{' <<< cons_symbol <<< ' ' <<< expression <<< " & " <<< expressions <<< '}'
	(<<<) file (TupleSelect field field_nr expr) = file <<< expr <<<'.' <<< field_nr
	(<<<) file (Lambda vars expr) = file <<< '\\' <<< vars <<< " -> " <<< expr
	(<<<) file WildCard = file <<< '_'
	(<<<) file (MatchExpr _ cons expr) = file <<< cons <<< " =: " <<< expr
	(<<<) file EE = file <<< "** E **"
	(<<<) file (NoBind _) = file <<< "** NB **"
	(<<<) file (DynamicExpr {dyn_expr,dyn_uni_vars,dyn_type_code})     = writeVarPtrs (file <<< "dynamic " <<< dyn_expr <<< " :: dyn_uni_vars") dyn_uni_vars <<< "dyn_type_code=" <<< dyn_type_code 
//	(<<<) file (TypeCase type_case)      = file <<< type_case
	(<<<) file (TypeCodeExpression type_code)      = file <<< type_code
	(<<<) file (Constant symb _ _ _)         = file <<<  "** Constant **" <<< symb

	(<<<) file (ABCCodeExpr code_sequence do_inline)      = file <<< (if do_inline "code inline\n" "code\n") <<< code_sequence
	(<<<) file (AnyCodeExpr input output code_sequence)   = file <<< "code\n" <<< input <<< "\n" <<< output <<< "\n" <<< code_sequence

	(<<<) file (FreeVar {fv_name})         	= file <<< fv_name
	(<<<) file (ClassVariable info_ptr)         	= file <<< "ClassVariable " <<< ptrToInt info_ptr

	(<<<) file expr         				= abort ("<<< (Expression) [line 1290]" )//<<- expr)
	
instance <<< TypeCase
where
	(<<<) file {type_case_dynamic,type_case_patterns,type_case_default}
			= file <<< "typecase " <<< type_case_dynamic <<< "of\n" <<<
				type_case_patterns <<< type_case_default

instance <<< DynamicPattern
where
	(<<<) file {dp_type_patterns_vars,dp_var,dp_rhs,dp_type_code}
			= writeVarPtrs (file <<< dp_var <<< " :: ")  dp_type_patterns_vars <<<  dp_type_code <<< " = " <<< dp_rhs

writeVarPtrs file []
	= file
writeVarPtrs file vars
	= write_var_ptrs (file <<< '<') vars <<< '>'
	where
		write_var_ptrs file [var]
			= file <<< ptrToInt var
		write_var_ptrs file [var : vars]
			= write_var_ptrs (file <<< ptrToInt var <<< '.') vars
		
		
instance <<< TypeCodeExpression
where
	(<<<) file TCE_Empty
		= file
	(<<<) file (TCE_Var info_ptr)
		= file <<< "TCE_Var " <<< ptrToInt info_ptr
// MV ..
	(<<<) file (TCE_TypeTerm info_ptr)
		= file <<< "TCE_TypeTerm " <<< ptrToInt info_ptr
// .. MV	
	(<<<) file (TCE_Constructor index exprs)
		= file <<< "TCE_Constructor " <<< index <<< ' ' <<< exprs
	(<<<) file (TCE_Selector selectors info_ptr)
		= file <<< "TCE_Selector " <<< selectors <<< "VAR " <<< ptrToInt info_ptr

instance <<< Selection
where
	(<<<) file (RecordSelection selector _) = file <<< selector
	(<<<) file (ArraySelection _ _ index_expr) = file <<< '[' <<< index_expr <<< ']'
	(<<<) file (DictionarySelection var selections _ index_expr) = file <<< '(' <<< var <<< '.' <<< selections <<< ')' <<< '[' <<< index_expr <<< ']'

instance <<< LocalDefs
where
	(<<<) file (LocalParsedDefs defs) = file <<< defs
	(<<<) file (CollectedLocalDefs defs) = file <<< defs

instance <<< (NodeDef dst) | <<< dst 
where
	(<<<) file {nd_dst,nd_alts,nd_locals} = file <<< nd_dst <<< nd_alts <<< nd_locals


instance <<< CollectedLocalDefs
where
	(<<<) file {loc_functions,loc_nodes}
		= file <<< loc_functions <<< loc_nodes
/*
	(<<<) file {def_types,def_constructors,def_selectors,def_macros,def_classes,def_members,def_instances}
		= file <<< def_types <<< def_constructors <<< def_selectors <<< def_macros <<< def_classes <<< def_members <<< def_instances
*/

instance <<< ParsedExpr
where
	(<<<) file (PE_List exprs) = file <<< exprs
	(<<<) file (PE_Tuple args) = file <<< '(' <<< args <<< ')'
	(<<<) file (PE_Basic basic_value) = file <<< basic_value
	(<<<) file (PE_Selection is_unique expr selectors) =  file <<< expr <<< (if is_unique '!' '.') <<< selectors
	(<<<) file (PE_Update expr1 selections expr2) =  file <<< '{' <<< expr1  <<< " & " <<<  selections <<< " = " <<< expr2 <<< '}'
	(<<<) file (PE_Record PE_Empty _ fields) = file <<< '{' <<< fields <<< '}'
	(<<<) file (PE_Record rec _ fields) = file <<< '{' <<< rec <<< " & " <<< fields <<< '}'
	(<<<) file (PE_Compr True expr quals) = file <<< '[' <<< expr <<< " \\ " <<< quals <<< ']'
	(<<<) file (PE_Compr False expr quals) = file <<< '{' <<< expr <<< " \\ " <<< quals <<< '}'
	(<<<) file (PE_Sequ seq) = file <<< '[' <<< seq <<< ']'
	(<<<) file PE_Empty = file <<< "** E **"
	(<<<) file (PE_Ident symb) = file <<< symb
	(<<<) file PE_WildCard = file <<< '_'
	(<<<) file (PE_Lambda _ exprs expr _) = file <<< '\\' <<< exprs <<< " -> " <<< expr
	(<<<) file (PE_Bound bind) = file <<< bind
	(<<<) file (PE_Case _ expr alts) = file <<< "case " <<< expr <<< " of\n" <<< alts
	(<<<) file (PE_Let _ defs expr) = file <<< "let " <<< defs <<< " in\n" <<< expr
	(<<<) file (PE_DynamicPattern expr type) = file <<< expr <<< "::" <<< type
	(<<<) file (PE_Dynamic expr maybetype)
		= case maybetype of
			Yes type
				-> file <<< "dynamic " <<< expr <<< "::" <<< type
			No
				-> file <<< "dynamic " <<< expr
	(<<<) file _ = file <<< "some expression"


instance <<< ParsedSelection
where
	(<<<) file (PS_Record selector _)	= file <<< selector
	(<<<) file (PS_Array index_expr)	= file <<< '[' <<< index_expr <<< ']'
	(<<<) file PS_Erroneous				= file <<< "Erroneous selector" // PK

instance <<< CaseAlt
where
	(<<<) file {calt_pattern,calt_rhs} = file <<< calt_pattern <<< " -> " <<< calt_rhs

instance <<< ParsedBody
where
	(<<<) file {pb_args,pb_rhs} = file <<< pb_args <<< " = " <<< pb_rhs
	
instance <<< BackendBody
where
	(<<<) file {bb_args,bb_rhs} = file <<< bb_args <<< " = " <<< bb_rhs

instance <<< FunctionPattern
where
	(<<<) file (FP_Basic val (Yes var))
		= file <<< var <<< "=:" <<< val
	(<<<) file (FP_Basic val No)
		= file <<< val
	(<<<) file (FP_Algebraic constructor vars (Yes var))
		= file <<< var <<< "=:" <<< constructor <<< vars
	(<<<) file (FP_Algebraic constructor vars No)
		= file <<< constructor <<< vars
	(<<<) file (FP_Variable var) = file <<< var 
	(<<<) file (FP_Dynamic vars var type_code _)
		= writeVarPtrs (file <<< var <<< " :: ") vars <<<  type_code
	(<<<) file (FP_Empty) = file <<< '_' 


instance <<< FunKind
where
	(<<<) file (FK_Function False) = file <<< "FK_Function"
	(<<<) file (FK_Function True) = file <<< "Lambda"
	(<<<) file FK_Macro = file <<< "FK_Macro"
	(<<<) file FK_Caf = file <<< "FK_Caf"
	(<<<) file FK_Unknown = file <<< "FK_Unknown"

instance <<< FunDef
where
	(<<<) file {fun_symb,fun_index,fun_body=ParsedBody bodies} = file <<< fun_symb <<< '.' <<< fun_index <<< ' ' <<< bodies 
	(<<<) file {fun_symb,fun_index,fun_body=CheckedBody {cb_args,cb_rhs},fun_info={fi_free_vars,fi_def_level,fi_calls}} = file <<< fun_symb <<< '.'
			<<< fun_index <<< "C " <<< cb_args <<< " = " <<< cb_rhs 
//			<<< fun_index <<< '.' <<< fi_def_level <<< ' ' <<< '[' <<< fi_free_vars <<< ']' <<< cb_args <<< " = " <<< cb_rhs 
	(<<<) file {fun_symb,fun_index,fun_body=TransformedBody {tb_args,tb_rhs},fun_info={fi_free_vars,fi_def_level,fi_calls}} = file <<< fun_symb <<< '.'
			<<< fun_index <<< "T "  <<< tb_args <<< '[' <<< fi_calls <<< ']' <<< " = " <<< tb_rhs 
//			<<< fun_index <<< '.' <<< fi_def_level <<< ' ' <<< '[' <<< fi_free_vars <<< ']' <<< tb_args <<< " = " <<< tb_rhs 
	(<<<) file {fun_symb,fun_index,fun_body=BackendBody body,fun_type=Yes type} = file <<< type <<< '\n' <<< fun_symb <<< '.'
			<<< fun_index <<< body <<< '\n'
	(<<<) file {fun_symb,fun_index,fun_body=NoBody,fun_type=Yes type} = file <<< type <<< '\n' <<< fun_symb <<< '.'
			<<< fun_index <<< "Array function\n"

instance <<< FunCall
where
	(<<<) file { fc_level,fc_index }
			= file <<< fc_index <<< '.' <<< fc_level

instance <<< FreeVar
where
	(<<<) file {fv_name,fv_info_ptr,fv_count} = file <<< fv_name <<< '.' <<< fv_count <<< '<' <<< ptrToInt fv_info_ptr <<< '>'

instance <<< DynamicType
where
	(<<<) file {dt_uni_vars,dt_type}
		| isEmpty dt_uni_vars
			= file <<< "DynamicType" <<< dt_type
			= file <<< "DynamicType" <<< "A." <<< dt_uni_vars <<< ":" <<< dt_type
			

instance <<< SignClassification
where
	(<<<) file {sc_pos_vect,sc_neg_vect} = write_signs file sc_pos_vect sc_neg_vect 0
	where
		write_signs file sc_pos_vect sc_neg_vect index
			| sc_pos_vect == 0 && sc_neg_vect == 0
				= file
			#	index_bit = (1 << index)
			| sc_pos_vect bitand index_bit == 0
				| sc_neg_vect bitand index_bit == 0
					= write_signs (file <<< 'O') sc_pos_vect sc_neg_vect (inc index)
					= write_signs (file <<< '-') sc_pos_vect (sc_neg_vect bitand (bitnot index_bit)) (inc index)
				| sc_neg_vect bitand index_bit == 0
					= write_signs (file <<< '+') (sc_pos_vect bitand (bitnot index_bit)) sc_neg_vect (inc index)
					= write_signs (file <<< 'T') (sc_pos_vect bitand (bitnot index_bit)) (sc_neg_vect bitand (bitnot index_bit)) (inc index)
				
instance <<< TypeKind
where
	(<<<) file (KindVar _) = file <<< "**"
	(<<<) file KindConst
		= file <<< '*'
	(<<<) file (KindArrow arity)
		= write_kinds file arity
	where
		write_kinds file 1
			= file <<< "* -> *"
		write_kinds file n
			= write_kinds (file <<< "* -> ") (dec n)
		

instance <<< TypeDefInfo
where
	(<<<) file {tdi_group,tdi_group_vars,tdi_cons_vars}
		= file <<< '[' <<< tdi_group <<< '=' <<< tdi_group_vars <<< '=' <<< tdi_cons_vars <<< ']'

instance <<< DefinedSymbol
where
	(<<<) file {ds_ident}
		= file <<< ds_ident 

instance <<< (TypeDef a) | <<< a
where
	(<<<) file {td_name, td_args, td_rhs}
		= file <<< ":: " <<< td_name <<< ' ' <<< td_args <<< td_rhs

instance <<< TypeRhs
where
	(<<<) file (SynType type)
		= file <<< " :== " <<< type 
	(<<<) file (AlgType data)
		= file <<< " = " <<< data 
	(<<<) file (RecordType record)
		= file <<< " = " <<< '{' <<< record <<< '}'
	(<<<) file _
		= file 


instance <<< RecordType
where
	(<<<) file {rt_fields} = iFoldSt (\index file -> file <<< rt_fields.[index]) 0 (size rt_fields) file

instance <<< FieldSymbol
where
	(<<<) file {fs_name} = file <<< fs_name

/*
	where
		write_data_defs file []
			= file
		write_data_defs file [d:ds]
			= write_data_defs (file <<< d <<< '\n') ds
*/

instance <<< InstanceType
where
	(<<<) file it = write_contexts it.it_context (file <<< it.it_types) 

instance <<< RhsDefsOfType
where
	(<<<) file (ConsList cons_defs) = file <<< cons_defs
	(<<<) file (SelectorList _ _ sel_defs) = file <<< sel_defs
	(<<<) file (TypeSpec type) = file <<< type
	(<<<) file _ = file

instance <<< ParsedConstructor
where
	(<<<) file {pc_cons_name,pc_arg_types} = file <<< pc_cons_name <<< pc_arg_types

instance <<< ParsedSelector
where
	(<<<) file {ps_field_name,ps_field_type} = file <<< ps_field_name <<< ps_field_type


instance <<< ModuleKind
where
	(<<<) file kind 		= file

instance <<< ConsDef
where
	(<<<) file {cons_symb,cons_type} = file <<< cons_symb <<< " :: " <<< cons_type

instance <<< SelectorDef
where
	(<<<) file {sd_symb} = file <<< sd_symb

instance <<< ClassDef
where
	(<<<) file {class_name} = file <<< class_name

instance <<< ClassInstance
where
	(<<<) file {ins_class,ins_type} = file <<< ins_class <<< " :: " <<< ins_type

instance <<< (Optional a) | <<< a
where
	(<<<) file (Yes x) = file <<< x
	(<<<) file No = file
	
instance <<< (Module a) | <<< a
where
	(<<<) file {mod_name,mod_type,mod_defs} = file <<< mod_type <<< mod_name <<< mod_defs

instance <<< (CollectedDefinitions a b) | <<< a & <<< b
where
	(<<<) file {def_types,def_constructors,def_selectors,def_macros,def_classes,def_members,def_instances}
		= file

instance <<< ParsedDefinition
where
	(<<<) file (PD_Function _ name _ exprs rhs _ ) = file <<< name <<< exprs <<< " = " <<< rhs
	(<<<) file (PD_NodeDef  _ pattern rhs) = file <<< pattern <<< " =: " <<< rhs
	(<<<) file (PD_TypeSpec _ name prio st sp) = file <<< name <<< st
	(<<<) file (PD_Type td) = file <<< td
	(<<<) file _ = file

instance <<< Rhs
where
	(<<<) file {rhs_alts,rhs_locals} = file <<< rhs_alts <<< rhs_locals

instance <<< OptGuardedAlts
where
	(<<<) file (GuardedAlts guarded_exprs def_expr) = file <<< guarded_exprs <<< def_expr
	(<<<) file (UnGuardedExpr unguarded_expr) = file <<< unguarded_expr

instance <<< ExprWithLocalDefs
where
	(<<<) file {ewl_expr,ewl_locals} = file <<< ewl_expr <<< ewl_locals

instance <<< GuardedExpr
where
	(<<<) file {alt_nodes,alt_guard,alt_expr} = file <<< '|' <<< alt_guard <<< alt_expr


instance <<< IndexRange
where
	(<<<) file {ir_from,ir_to}
		| ir_from == ir_to
			= file
			= file <<< ir_from <<< "---" <<< ir_to

instance <<< Ident
where
//	(<<<) file {id_name,id_index} = file <<< id_name <<< '.' <<< id_index
	(<<<) file {id_name} = file <<< id_name

instance <<< (Global a) | <<< a
where
	(<<<) file {glob_object,glob_module} = file <<< glob_object <<< "M:" <<< glob_module

instance <<< Position
where
	(<<<) file (FunPos file_name line func) = file <<< '[' <<< file_name <<< ',' <<< line <<< ',' <<< func <<< ']'
	(<<<) file (LinePos file_name line) = file <<< '[' <<< file_name <<< ',' <<< line <<< ']'
	(<<<) file _ = file

instance <<< TypeVarInfo
where
	(<<<) file TVI_Empty				= file <<< "TVI_Empty"
	(<<<) file (TVI_Type _)				= file <<< "TVI_Type"
	(<<<) file (TVI_Forward	_) 			= file <<< "TVI_Forward"
	(<<<) file (TVI_TypeKind _)			= file <<< "TVI_TypeKind"
	(<<<) file (TVI_SignClass _ _ _) 	= file <<< "TVI_SignClass"
	(<<<) file (TVI_PropClass _ _ _) 	= file <<< "TVI_PropClass"

instance <<< (Import from_symbol) | <<< from_symbol
where
	(<<<) file {import_module, import_symbols}
		= file <<< "import " <<< import_module <<< import_symbols

instance <<< ImportDeclaration
where
	(<<<) file (ID_Function ident)			= file <<< ident
	(<<<) file (ID_Class ident optIdents)	= file <<< "class " <<< ident <<< optIdents
	(<<<) file (ID_Type ident optIdents)	= file <<< ":: " <<< ident <<< optIdents
	(<<<) file (ID_Record ident optIdents)	= file <<< ident <<< " { " <<< optIdents <<< " } "
	(<<<) file (ID_Instance i1 i2 tup)		= file <<< "instance " <<< i1 <<< i2 <<< tup // !ImportedIdent !Ident !(![Type],![TypeContext])

instance <<< ImportedIdent
where
	(<<<) file {ii_ident, ii_extended}	= file <<< ii_ident <<< ' ' <<< ii_extended

instance == ModuleKind
where
	(==) mk1 mk2 = equal_constructor mk1 mk2

instance == TypeAttribute
where
	(==) attr1 attr2 = equal_constructor attr1 attr2

instance == Annotation
where
	(==) a1 a2 = equal_constructor a1 a2

EmptySymbolTableEntry :== 
	{	ste_kind = STE_Empty, ste_index = NoIndex, ste_def_level = NotALevel, ste_previous = abort "empty SymbolTableEntry" }

cNotAGroupNumber :== -1

EmptyTypeDefInfo :== { tdi_kinds = [], tdi_properties = cAllBitsClear, tdi_group = [], tdi_group_vars = [], tdi_cons_vars = [],
					   tdi_classification = EmptyTypeClassification, tdi_group_nr = cNotAGroupNumber, tdi_tmp_index = NoIndex }

MakeTypeVar name :== { tv_name = name, tv_info_ptr = nilPtr }
MakeVar name :== { var_name = name, var_info_ptr = nilPtr, var_expr_ptr = nilPtr }

MakeAttributedType type :== { at_attribute = TA_None, at_annotation = AN_None, at_type = type }
MakeAttributedTypeVar type_var :== { atv_attribute = TA_None, atv_annotation = AN_None, atv_variable = type_var }

EmptyFunInfo :== { fi_calls = [], fi_group_index = NoIndex, fi_def_level = NotALevel,
				   fi_free_vars = [], fi_local_vars = [], fi_dynamics = [], fi_is_macro_fun=False }

BottomSignClass		:== { sc_pos_vect = 0, sc_neg_vect = 0 }
PostiveSignClass	:== { sc_pos_vect = bitnot 0, sc_neg_vect = 0 }

NoPropClass			:== 0
PropClass			:== bitnot 0

MakeNewTypeSymbIdent name arity
	:== MakeTypeSymbIdent { glob_object = NoIndex, glob_module = NoIndex } name arity

MakeTypeSymbIdent type_index name arity
	:== {	type_name = name, type_arity = arity, type_index = type_index,
			type_prop = { tsp_sign = BottomSignClass, tsp_propagation = NoPropClass, tsp_coercible = True }}

MakeSymbIdent name arity	:== { symb_name = name, symb_kind = SK_Unknown, symb_arity = arity }
MakeConstant name			:== MakeSymbIdent name 0

ParsedSelectorToSelectorDef ps :==
	{	sd_symb = ps.ps_selector_name, sd_field_nr = NoIndex, sd_pos =  ps.ps_field_pos, sd_type_index = NoIndex,
		sd_exi_vars = [], sd_type_ptr = nilPtr, sd_field = ps.ps_field_name,
		sd_type	= { st_vars = [], st_args = [], st_result = ps.ps_field_type, st_arity = 0, st_context = [],
				    st_attr_env = [], st_attr_vars = [] }}

ParsedConstructorToConsDef pc :==
	{	cons_symb = pc.pc_cons_name, cons_pos = pc.pc_cons_pos, cons_priority = pc.pc_cons_prio, cons_index = NoIndex, cons_type_index = NoIndex,
		cons_type = { st_vars = [], st_args = pc.pc_arg_types, st_result = MakeAttributedType TE, 
				  st_arity = pc.pc_cons_arity, st_context = [], st_attr_env = [], st_attr_vars = []},
		cons_exi_vars = pc.pc_exi_vars, cons_type_ptr = nilPtr, cons_arg_vars = [] }

ParsedInstanceToClassInstance pi members :==
 	{	ins_class = {glob_object = MakeDefinedSymbol pi.pi_class NoIndex (length pi.pi_types), glob_module = NoIndex}, ins_ident = pi.pi_ident, 
 		ins_type = { it_vars = [], it_types = pi.pi_types, it_attr_vars = [],
 					 it_context = pi.pi_context }, ins_members = members, ins_specials = pi.pi_specials, ins_pos = pi.pi_pos }

MakeTypeDef name lhs rhs attr contexts pos  :== 
	{	td_name = name, td_index = -1, td_arity = length lhs, td_args = lhs, td_attrs = [], td_attribute = attr, td_context = contexts,
		td_pos = pos, td_rhs = rhs }

MakeDefinedSymbol ident index arity :== { ds_ident = ident, ds_arity = arity, ds_index = index }

MakeNewFunctionType name arity prio type pos specials var_ptr
	:== { ft_symb = name, ft_arity = arity, ft_priority = prio, ft_type = type, ft_pos = pos, ft_specials = specials, ft_type_ptr = var_ptr  }