bugfixes

git-svn-id: https://svn.cs.ru.nl/repos/clean-compiler/trunk@122 1f8540f1-abd5-4d5b-9d24-4c5ce8603e2d

8 files changed, 101 insertions, 141 deletions

diff --git a/frontend/check.icl b/frontend/check.icl
index 86a4cf4..6b3461d 100644
--- a/frontend/check.icl
+++ b/frontend/check.icl
@@ -2611,7 +2611,7 @@ checkModule {mod_type,mod_name,mod_imports,mod_imported_objects,mod_defs = cdefs
 	  (icl_functions, e_info, heaps, cs) = checkMacros cIclModIndex cdefs.def_macros icl_functions e_info heaps cs
 	  (icl_functions, e_info, heaps, cs) = checkFunctions cIclModIndex cGlobalScope 0 nr_of_global_funs icl_functions e_info heaps cs
 
-	  (e_info, cs) = check_needed_modules_are_imported mod_name ".icl" e_info cs
+	  cs = check_needed_modules_are_imported mod_name ".icl" cs
 
 	  (icl_functions, e_info, heaps, {cs_symbol_table, cs_predef_symbols, cs_error})
 	  	= checkInstanceBodies {ir_from = first_inst_index, ir_to = nr_of_functions} icl_functions e_info heaps cs
@@ -2831,28 +2831,31 @@ checkModule {mod_type,mod_name,mod_imports,mod_imported_objects,mod_defs = cdefs
 				  (Yes symbol_type) = inst_def.fun_type
 				= { instance_defs & [ds_index] = { inst_def & fun_type = Yes (makeElemTypeOfArrayFunctionStrict symbol_type ins_offset offset_table) } }
 
-check_needed_modules_are_imported mod_name extension e_info cs=:{cs_needed_modules}
-	# (e_info, cs) = case cs_needed_modules bitand cNeedStdDynamics of
-						0 -> (e_info, cs)
-						_ -> check_it PD_StdDynamics mod_name extension e_info cs
-	# (e_info, cs) = case cs_needed_modules bitand cNeedStdArray of
-						0 -> (e_info, cs)
-						_ -> check_it PD_StdArray mod_name extension e_info cs
-	# (e_info, cs) = case cs_needed_modules bitand cNeedStdEnum of
-						0 -> (e_info, cs)
-						_ -> check_it PD_StdEnum mod_name extension e_info cs
-	= (e_info, cs)
+check_needed_modules_are_imported mod_name extension cs=:{cs_needed_modules}
+	# cs = case cs_needed_modules bitand cNeedStdDynamics of
+			0 -> cs
+			_ -> check_it PD_StdDynamics mod_name extension cs
+	# cs = case cs_needed_modules bitand cNeedStdArray of
+			0 -> cs
+			_ -> check_it PD_StdArray mod_name extension cs
+	# cs = case cs_needed_modules bitand cNeedStdEnum of
+			0 -> cs
+			_ -> check_it PD_StdEnum mod_name extension cs
+	= cs
   where
-	check_it pd mod_name extension e_info=:{ef_modules} cs=:{cs_predef_symbols}
+	check_it pd mod_name extension cs=:{cs_predef_symbols, cs_symbol_table}
   		#! {pds_ident} = cs_predef_symbols.[pd]	
-		   is_imported = any ((==) pds_ident) [ dcl_name \\ {dcl_name}<-:ef_modules ]
-		| is_imported
-			= (e_info, cs)
-		# error_location = { ip_ident = mod_name, ip_line = 1, ip_file = mod_name.id_name+++extension}
-		  cs_error = pushErrorAdmin error_location cs.cs_error
-		  cs_error = checkError pds_ident "not imported" cs_error
-		  cs_error = popErrorAdmin cs_error
-		= (e_info, { cs & cs_error = cs_error })
+		# ({ste_kind}, cs_symbol_table) = readPtr pds_ident.id_info cs_symbol_table
+		  cs = { cs & cs_symbol_table = cs_symbol_table }
+		= case ste_kind of
+			STE_ClosedModule
+				-> cs
+			STE_Empty
+				# error_location = { ip_ident = mod_name, ip_line = 1, ip_file = mod_name.id_name+++extension}
+				  cs_error = pushErrorAdmin error_location cs.cs_error
+				  cs_error = checkError pds_ident "not imported" cs_error
+				  cs_error = popErrorAdmin cs_error
+				-> { cs & cs_error = cs_error }
 
 arrayFunOffsetToPD_IndexTable :: !{# MemberDef} !v:{# PredefinedSymbol} -> (!{# Index}, !{#MemberDef}, !v:{#PredefinedSymbol})
 arrayFunOffsetToPD_IndexTable member_defs predef_symbols
@@ -2992,7 +2995,7 @@ checkDclModule {mod_name,mod_imports,mod_defs} mod_index modules icl_functions h
 	  (icl_functions, e_info, heaps, cs)
 			= checkMacros mod_index dcl_macros icl_functions e_info heaps { cs & cs_error = cs_error }
 
-	  (e_info, cs) = check_needed_modules_are_imported mod_name ".dcl" e_info cs
+	  cs = check_needed_modules_are_imported mod_name ".dcl" cs
 
 	  com_instance_defs = dcl_common.com_instance_defs
 	  com_instance_defs = { inst_def \\ inst_def <- [ inst_def \\ inst_def <-: com_instance_defs ] ++ new_class_instances }
diff --git a/frontend/comparedefimp.icl b/frontend/comparedefimp.icl
index 41bf4e7..296ab9c 100644
--- a/frontend/comparedefimp.icl
+++ b/frontend/comparedefimp.icl
@@ -409,6 +409,8 @@ instance t_corresponds AType where
 		= t_corresponds_at_type dclDef iclDef
 	  where
 		t_corresponds_at_type dclDef iclDef tc_state
+			| dclDef.at_annotation<>iclDef.at_annotation
+				= (False, tc_state)
 			# (corresponds, tc_state) = simple_corresponds dclDef iclDef tc_state
 			| corresponds
 				= (corresponds, tc_state)
@@ -419,13 +421,13 @@ instance t_corresponds AType where
 					#! x = sreadPtr tv_info_ptr tc_state.tc_type_vars.hwn_heap
 					-> case x of
 						TVI_AType dcl_atype
-							-> t_corresponds dcl_atype iclDef tc_state
+							-> t_corresponds { dcl_atype & at_annotation = dclDef.at_annotation } iclDef tc_state
 						_	-> (False, tc_state)
 				_	-> (False, tc_state)
 		  where
+
 			simple_corresponds dclDef iclDef
 				=	t_corresponds dclDef.at_attribute iclDef.at_attribute
-				&&&	equal dclDef.at_annotation iclDef.at_annotation
 				&&&	t_corresponds dclDef.at_type iclDef.at_type
 
 			corresponds_with_expanded_syn_type {glob_module, glob_object} dclArgs icl_atype
@@ -472,7 +474,7 @@ instance t_corresponds AType where
 					# (actual_arg, type_var_heap) = possibly_dereference actual_arg type_var_heap
 					= bind_type_vars` formal_args actual_args
 							(writePtr atv_variable.tv_info_ptr (TVI_AType actual_arg) type_var_heap)
-							//	--->("binding", atv_variable.tv_name,"to",actual_arg)
+//								--->("binding", atv_variable.tv_name,"to",actual_arg)
 				bind_type_vars` _ _ type_var_heap
 					= type_var_heap
 				
diff --git a/frontend/explicitimports.icl b/frontend/explicitimports.icl
index f0c3623..b10df13 100644
--- a/frontend/explicitimports.icl
+++ b/frontend/explicitimports.icl
@@ -783,8 +783,8 @@ instance consequences Expression
 instance consequences FunctionBody
   where	consequences (CheckedBody body) = consequences body
 		consequences (TransformedBody body) = consequences body
-		consequences (RhsMacroBody body) = consequences body
-		
+		// other alternatives should not occur
+				
 instance consequences FunType
   where
 	consequences {ft_type}	= consequences ft_type	
diff --git a/frontend/frontend.icl b/frontend/frontend.icl
index d779c35..bde4809 100644
--- a/frontend/frontend.icl
+++ b/frontend/frontend.icl
@@ -22,6 +22,7 @@ frontEndInterface :: !Ident !SearchPaths !*PredefinedSymbols !*HashTable !*Files
 frontEndInterface mod_ident search_paths predef_symbols hash_table files error io out
 	# (ok, mod, hash_table, error, predef_symbols, files)
 		= wantModule cWantIclFile mod_ident (hash_table ---> ("Parsing:", mod_ident)) error search_paths predef_symbols files
+	#! mod_type = mod.mod_type
 	| not ok
 		= (predef_symbols, hash_table, files, error, io, out, No)
 	# (ok, mod, nr_of_global_funs, mod_functions, dcl_mod, predef_mod, modules, hash_table, error, predef_symbols, files)
@@ -37,7 +38,7 @@ frontEndInterface mod_ident search_paths predef_symbols hash_table files error i
 	# {icl_functions,icl_instances,icl_specials,icl_common,icl_declared={dcls_import}} = icl_mod
 //	  (components, icl_functions, error) = showComponents components 0 True icl_functions error
 	  (ok, fun_defs, array_instances, type_code_instances, common_defs, imported_funs, heaps, predef_symbols, error)
-		= typeProgram (components -*-> "Typing") icl_functions icl_specials icl_common dcls_import dcl_mods heaps predef_symbols error
+		= typeProgram mod_type (components -*-> "Typing") icl_functions icl_specials icl_common dcls_import dcl_mods heaps predef_symbols error
 	| not ok
 		= (predef_symbols, hash_table, files, error, io, out, No)
 
diff --git a/frontend/part.icl b/frontend/part.icl
deleted file mode 100644
index 8a080e2..0000000
--- a/frontend/part.icl
+++ /dev/null
@@ -1,92 +0,0 @@
-module part
-
-import StdEnv
-
-import syntax, transform, checksupport, StdCompare, check, utilities
-
-::	PartitioningInfo = 
-	{	pi_marks :: 		!.{# Int}
-	,	pi_next_num ::		!Int
-	,	pi_next_group ::	!Int
-	,	pi_groups ::		![[Int]]
-	,	pi_deps ::			![Int]
-	}
-
-NotChecked :== -1	
-
-Start = 3
-
-partitionateFunctions :: !*{# FunDef} !*{# FunDef} -> (!{! Group}, !*{# FunDef}, !*{# FunDef})
-partitionateFunctions fun_defs inst_defs
-	#! nr_of_functions = size fun_defs
-	   nr_of_instances = size inst_defs
-	#! max_fun_nr = nr_of_functions + nr_of_instances
-	# partitioning_info = { pi_marks = createArray max_fun_nr NotChecked, pi_deps = [], pi_next_num = 0, pi_next_group = 0, pi_groups = [] }
-	  (fun_defs, inst_defs, {pi_groups,pi_next_group}) = partitionate_functions 0 max_fun_nr nr_of_functions fun_defs inst_defs partitioning_info
-	  groups = { {group_members = group} \\ group <- reverse pi_groups }
-	= (groups, fun_defs, inst_defs)
-where
-	partitionate_functions :: !Int !Int !Int !*{# FunDef} !*{# FunDef} !*PartitioningInfo -> (!*{# FunDef}, !*{# FunDef}, !*PartitioningInfo)
-	partitionate_functions from_index max_fun_nr nr_of_functions fun_defs inst_defs pi=:{pi_marks}
-		| from_index == max_fun_nr
-			= (fun_defs, inst_defs, pi)
-		| pi_marks.[from_index] == NotChecked
-			# (_, fun_defs, inst_defs, pi) = partitionate_function from_index max_fun_nr nr_of_functions fun_defs inst_defs pi
-			= partitionate_functions (inc from_index) max_fun_nr nr_of_functions fun_defs inst_defs pi
-			= partitionate_functions (inc from_index) max_fun_nr nr_of_functions fun_defs inst_defs pi
-
-	partitionate_function :: !Int !Int !Int !*{# FunDef} !*{# FunDef} !*PartitioningInfo -> *(!Int, !*{# FunDef}, !*{# FunDef}, !*PartitioningInfo)
-	partitionate_function fun_index max_fun_nr nr_of_functions fun_defs inst_defs pi=:{pi_next_num}
-		| fun_index < nr_of_functions
-			#! fd = fun_defs.[fun_index]
-			| fd.fun_kind
-				# {fi_calls,fi_instance_calls} = fd.fun_info
-				  (min_dep, fun_defs, inst_defs, pi) = visit_functions fi_calls max_fun_nr max_fun_nr nr_of_functions fun_defs inst_defs (push_on_dep_stack fun_index pi)
-				  (min_dep, fun_defs, inst_defs, pi) = visit_functions fi_calls min_dep max_fun_nr nr_of_functions fun_defs inst_defs pi
-				= try_to_close_group fun_index pi_next_num min_dep max_fun_nr nr_of_functions fun_defs inst_defs pi
-			#! fd = inst_defs.[fun_index-nr_of_functions]
-			# {fi_calls,fi_instance_calls} = fd.fun_info
-			  (min_dep, fun_defs, inst_defs, pi) = visit_functions fi_calls max_fun_nr max_fun_nr nr_of_functions fun_defs inst_defs (push_on_dep_stack fun_index pi)
-			  (min_dep, fun_defs, inst_defs, pi) = visit_functions fi_calls min_dep max_fun_nr nr_of_functions fun_defs inst_defs pi
-			= try_to_close_group fun_index pi_next_num min_dep max_fun_nr nr_of_functions fun_defs inst_defs pi
-				  
-	push_on_dep_stack :: !Int !*PartitioningInfo -> *PartitioningInfo;
-	push_on_dep_stack fun_index pi=:{pi_deps,pi_marks,pi_next_num}
-		= { pi & pi_deps = [fun_index : pi_deps], pi_marks = { pi_marks & [fun_index] = pi_next_num}, pi_next_num = inc pi_next_num}
-
-	visit_functions :: ![FunCall] !Int !Int !Int !*{# FunDef} !*{# FunDef} !*PartitioningInfo -> *(!Int, !*{# FunDef}, !*{# FunDef}, !*PartitioningInfo)
-	visit_functions [{fc_index}:funs] min_dep max_fun_nr nr_of_functions fun_defs inst_defs pi=:{pi_marks} 
-		#! mark = pi_marks.[fc_index]
-		| mark == NotChecked
-			# (mark, fun_defs, inst_defs, pi) = partitionate_function fc_index max_fun_nr nr_of_functions fun_defs inst_defs  pi
-			= visit_functions funs (min min_dep mark) max_fun_nr nr_of_functions fun_defs inst_defs pi
-			= visit_functions funs (min min_dep mark) max_fun_nr nr_of_functions fun_defs inst_defs pi
-	visit_functions [] min_dep max_fun_nr nr_of_functions fun_defs inst_defs pi
-		= (min_dep, fun_defs, inst_defs, pi)
-		
-
-	try_to_close_group :: !Int !Int !Int !Int !Int !*{# FunDef} !*{# FunDef} !*PartitioningInfo -> *(!Int, !*{# FunDef}, !*{# FunDef}, !*PartitioningInfo)
-	try_to_close_group fun_index fun_nr min_dep max_fun_nr nr_of_functions fun_defs inst_defs pi=:{pi_marks, pi_deps, pi_groups, pi_next_group}
-		| fun_nr <= min_dep
-			# (pi_deps, pi_marks, group, fun_defs, inst_defs)
-				= close_group fun_index pi_deps pi_marks [] max_fun_nr nr_of_functions pi_next_group fun_defs inst_defs
-				
-			  pi = { pi & pi_deps = pi_deps, pi_marks = pi_marks, pi_next_group = inc pi_next_group,  pi_groups = [group : pi_groups] }
-			= (max_fun_nr, fun_defs, inst_defs, pi)
-			= (min_dep, fun_defs, inst_defs, pi)
-	where
-		close_group :: !Int ![Int] !*{# Int} ![Int] !Int !Int !Index !*{# FunDef} !*{# FunDef} -> (![Int], !*{# Int}, ![Int], !*{# FunDef}, !*{# FunDef})
-		close_group fun_index [d:ds] marks group max_fun_nr nr_of_functions group_number fun_defs inst_defs
-			#! fd = fun_defs.[d]
-			# marks = { marks & [d] = max_fun_nr }
-			| d < nr_of_functions
-				#! fd = fun_defs.[d]
-				# fun_defs = { fun_defs & [d] = { fd & fun_info.fi_group_index = group_number }}
-				| d == fun_index
-					= (ds, marks, [d : group], fun_defs, inst_defs)
-					= close_group fun_index ds marks group max_fun_nr nr_of_functions group_number fun_defs inst_defs
-				#! fd = inst_defs.[d-nr_of_functions]
-				# inst_defs = { inst_defs & [d] = { fd & fun_info.fi_group_index = group_number }}
-				| d == fun_index
-					= (ds, marks, [d : group], fun_defs, inst_defs)
-					= close_group fun_index ds marks group max_fun_nr nr_of_functions group_number fun_defs inst_defs
diff --git a/frontend/transform.icl b/frontend/transform.icl
index d6972ae..4adb5b8 100644
--- a/frontend/transform.icl
+++ b/frontend/transform.icl
@@ -549,9 +549,9 @@ partitionateMacros {ir_from,ir_to} mod_index fun_defs modules var_heap symbol_he
 	# partitioning_info = { pi_var_heap = var_heap, pi_symbol_heap = symbol_heap,
 							pi_symbol_table = symbol_table,
 							pi_error = error, pi_deps = [], pi_next_num = 0, pi_next_group = 0, pi_groups = [] }
-	  (fun_defs, modules, {pi_symbol_table, pi_var_heap, pi_symbol_heap, pi_error, pi_next_group, pi_groups, pi_marks})
+	  (fun_defs, modules, {pi_symbol_table, pi_var_heap, pi_symbol_heap, pi_error, pi_next_group, pi_groups, pi_marks, pi_deps})
 	  		= iFoldSt (pationate_macro mod_index max_fun_nr) ir_from ir_to (fun_defs, modules, partitioning_info)
-	= (iFoldSt reset_body_of_rhs_macro ir_from ir_to fun_defs, modules, pi_var_heap, pi_symbol_heap, pi_symbol_table, pi_error)
+	= (foldSt reset_body_of_rhs_macro pi_deps fun_defs, modules, pi_var_heap, pi_symbol_heap, pi_symbol_table, pi_error)
 where
 	
 	reset_body_of_rhs_macro macro_index macro_defs
@@ -592,6 +592,7 @@ where
 			  			fun_info = { fun_info & fi_calls = fi_calls, fi_local_vars = local_vars }}
 			= ({ macro_defs & [macro_index] = macro }, modules,
 					{ pi & pi_symbol_table = es_symbol_table, pi_symbol_heap = es_symbol_heap, pi_var_heap = es_var_heap, pi_error = es_error })
+			# pi = { pi & pi_deps = [macro_index:pi.pi_deps] }
 			= ({ macro_defs & [macro_index] = { macro & fun_body = RhsMacroBody body }}, modules, pi)
 
 	macros_are_simple [] macro_defs
diff --git a/frontend/type.dcl b/frontend/type.dcl
index 9fe9b24..d0f9bcb 100644
--- a/frontend/type.dcl
+++ b/frontend/type.dcl
@@ -3,6 +3,7 @@ definition module type
 import StdArray
 import syntax, check
 
-typeProgram ::!{! Group} !*{# FunDef} !IndexRange !CommonDefs ![Declaration] !{# DclModule} !*Heaps !*PredefinedSymbols !*File
+// MW0 typeProgram ::!{! Group} !*{# FunDef} !IndexRange !CommonDefs ![Declaration] !{# DclModule} !*Heaps !*PredefinedSymbols !*File
+typeProgram :: !ModuleKind !{! Group} !*{# FunDef} !IndexRange !CommonDefs ![Declaration] !{# DclModule} !*Heaps !*PredefinedSymbols !*File
 	-> (!Bool, !*{# FunDef}, !IndexRange, {! GlobalTCType}, !{# CommonDefs}, !{# {# FunType} }, !*Heaps, !*PredefinedSymbols, !*File)
 
diff --git a/frontend/type.icl b/frontend/type.icl
index 9279beb..766841a 100644
--- a/frontend/type.icl
+++ b/frontend/type.icl
@@ -1371,9 +1371,11 @@ addLiftedArgumentsToSymbolType st=:{st_arity,st_args,st_vars,st_attr_vars,st_con
 	,	fe_location		:: !IdentPos
 	}
 
-typeProgram ::!{! Group} !*{# FunDef} !IndexRange !CommonDefs ![Declaration] !{# DclModule} !*Heaps !*PredefinedSymbols !*File
+// MW0 was typeProgram ::!{! Group} !*{# FunDef} !IndexRange !CommonDefs ![Declaration] !{# DclModule} !*Heaps !*PredefinedSymbols !*File
+typeProgram :: !ModuleKind !{! Group} !*{# FunDef} !IndexRange !CommonDefs ![Declaration] !{# DclModule} !*Heaps !*PredefinedSymbols !*File
 	-> (!Bool, !*{# FunDef}, !IndexRange, {! GlobalTCType}, !{# CommonDefs}, !{# {# FunType} }, !*Heaps, !*PredefinedSymbols, !*File)
-typeProgram comps fun_defs specials icl_defs imports modules {hp_var_heap, hp_expression_heap, hp_type_heaps} predef_symbols file
+// MW0 was typeProgram comps fun_defs specials icl_defs imports modules {hp_var_heap, hp_expression_heap, hp_type_heaps} predef_symbols file
+typeProgram mod_type comps fun_defs specials icl_defs imports modules {hp_var_heap, hp_expression_heap, hp_type_heaps} predef_symbols file
 	#! fun_env_size = size fun_defs
 	# ts_error = {ea_file = file, ea_loc = [], ea_ok = True }
 
@@ -1393,11 +1395,18 @@ typeProgram comps fun_defs specials icl_defs imports modules {hp_var_heap, hp_ex
 	  		 ts_type_heaps = { hp_type_heaps & th_vars = th_vars }, ts_td_infos = td_infos, ts_error = ts_error }
 	  ti = { ti_common_defs = ti_common_defs, ti_functions = ti_functions }
 	  special_instances = { si_next_array_member_index = fun_env_size, si_array_instances = [], si_next_TC_member_index = 0, si_TC_instances = [] }
-	# (type_error, fun_defs, predef_symbols, special_instances, ts) = type_components 0 comps  class_instances ti (False, fun_defs, predef_symbols, special_instances, ts)
-	  (fun_defs,ts_fun_env) = update_function_types 0 comps ts.ts_fun_env fun_defs
+// MW0 was	# (type_error, fun_defs, predef_symbols, special_instances, ts) = type_components 0 comps  class_instances ti (False, fun_defs, predef_symbols, special_instances, ts)
+	  (type_error, fun_defs, predef_symbols, special_instances, ts=:{ts_error})
+	  		= type_components 0 comps  class_instances ti (False, fun_defs, predef_symbols, special_instances, ts)
+// MW0 was	  (fun_defs,ts_fun_env) = update_function_types 0 comps ts.ts_fun_env fun_defs
+	  (fun_defs, ts_fun_env, ts_error=:{ea_ok=no_start_rule_error}) = update_function_types 0 comps ts.ts_fun_env fun_defs ts_error
+	    
 	  (type_error, fun_defs, predef_symbols, special_instances, {ts_fun_env,ts_error,ts_var_heap, ts_expr_heap, ts_type_heaps})
-			= type_instances specials.ir_from specials.ir_to class_instances ti (type_error, fun_defs, predef_symbols, special_instances,
-				{ ts & ts_fun_env = ts_fun_env })
+// MW0 was			= type_instances specials.ir_from specials.ir_to class_instances ti (type_error, fun_defs, predef_symbols, special_instances,
+// MW0 was				{ ts & ts_fun_env = ts_fun_env })
+			= type_instances specials.ir_from specials.ir_to class_instances ti
+				(type_error || not no_start_rule_error, fun_defs, predef_symbols, special_instances,
+					{ ts & ts_fun_env = ts_fun_env, ts_error = { ts_error & ea_ok = True }})
 	  {si_array_instances, si_next_array_member_index, si_next_TC_member_index, si_TC_instances}= special_instances
 	  (fun_defs, predef_symbols, ts_type_heaps) = convert_array_instances si_array_instances ti_common_defs fun_defs predef_symbols ts_type_heaps
 	  type_code_instances = {createArray si_next_TC_member_index GTT_Function & [gtci_index] = gtci_type \\ {gtci_index, gtci_type} <- si_TC_instances}
@@ -1654,31 +1663,49 @@ where
 		= (subst, ts_fun_env)
 			
 
-	update_function_types :: !Index !{!Group} !*{!FunctionType} !*{#FunDef} -> (!*{#FunDef}, !*{!FunctionType})
-	update_function_types group_index comps fun_env fun_defs
+// MW0 was	update_function_types :: !Index !{!Group} !*{!FunctionType} !*{#FunDef} -> (!*{#FunDef}, !*{!FunctionType})
+	update_function_types :: !Index !{!Group} !*{!FunctionType} !*{#FunDef} !*ErrorAdmin -> (!*{#FunDef}, !*{!FunctionType}, !.ErrorAdmin)
+	update_function_types group_index comps fun_env fun_defs error_admin
 		| group_index == size comps
-			= (fun_defs, fun_env)
+// MW0 was			= (fun_defs, fun_env)
+			= (fun_defs, fun_env, error_admin)
 			#! comp = comps.[group_index]	
-			# (fun_defs, fun_env) = update_function_types_in_component comp.group_members fun_env fun_defs
-			= update_function_types (inc group_index) comps fun_env fun_defs
+// MW0 was			# (fun_defs, fun_env) = update_function_types_in_component comp.group_members fun_env fun_defs
+			# (fun_defs, fun_env, error_admin) = update_function_types_in_component comp.group_members fun_env fun_defs error_admin
+// MW0 was			= update_function_types (inc group_index) comps fun_env fun_defs
+			= update_function_types (inc group_index) comps fun_env fun_defs error_admin
 
 	where
-		update_function_types_in_component :: ![Index] !*{!FunctionType} !*{#FunDef} -> (!*{#FunDef}, !*{!FunctionType})
-		update_function_types_in_component [ fun_index : funs ] fun_env fun_defs
+// MW0 was		update_function_types_in_component :: ![Index] !*{!FunctionType} !*{#FunDef} -> (!*{#FunDef}, !*{!FunctionType})
+		update_function_types_in_component :: ![Index] !*{!FunctionType} !*{#FunDef} !*ErrorAdmin
+											-> (!*{#FunDef}, !*{!FunctionType}, !.ErrorAdmin)
+// MW0 was		update_function_types_in_component [ fun_index : funs ] fun_env fun_defs
+		update_function_types_in_component [ fun_index : funs ] fun_env fun_defs error_admin
 			# (CheckedType checked_fun_type, fun_env) = fun_env![fun_index]
 			#! fd = fun_defs.[fun_index]
+// MW0..
+			# is_start_rule  = fd.fun_symb.id_name=="Start" && fd.fun_info.fi_def_level==1 && mod_type==MK_Main
+			  error_admin = case is_start_rule  of
+			  					False	-> error_admin
+			  					_		-> check_type_of_start_rule fd checked_fun_type error_admin
+// ..MW0
 			= case fd.fun_type of
 				No
-					-> update_function_types_in_component funs fun_env { fun_defs & [fun_index] = { fd & fun_type = Yes checked_fun_type }}
+// MW0 was					-> update_function_types_in_component funs fun_env { fun_defs & [fun_index] = { fd & fun_type = Yes checked_fun_type }}
+					-> update_function_types_in_component funs fun_env { fun_defs & [fun_index] = { fd & fun_type = Yes checked_fun_type }} error_admin
 				Yes fun_type
 					# nr_of_lifted_arguments = checked_fun_type.st_arity - fun_type.st_arity
 					| nr_of_lifted_arguments > 0
 						# fun_type = addLiftedArgumentsToSymbolType fun_type nr_of_lifted_arguments
 									checked_fun_type.st_args checked_fun_type.st_vars checked_fun_type.st_attr_vars checked_fun_type.st_context
-						-> update_function_types_in_component funs fun_env { fun_defs & [fun_index] = { fd & fun_type = Yes fun_type }}
-						-> update_function_types_in_component funs fun_env fun_defs
-		update_function_types_in_component [] fun_env fun_defs
-			= (fun_defs, fun_env)
+// MW0 was						-> update_function_types_in_component funs fun_env { fun_defs & [fun_index] = { fd & fun_type = Yes fun_type }}
+						-> update_function_types_in_component funs fun_env { fun_defs & [fun_index] = { fd & fun_type = Yes fun_type }} error_admin
+// MW0 was						-> update_function_types_in_component funs fun_env fun_defs
+						-> update_function_types_in_component funs fun_env fun_defs error_admin
+// MW0 was		update_function_types_in_component [] fun_env fun_defs
+// MW0 was			= (fun_defs, fun_env)
+		update_function_types_in_component [] fun_env fun_defs error_admin
+			= (fun_defs, fun_env, error_admin)
 	
 	type_functions group ti cons_variables fun_defs ts
 		= mapSt (type_function ti) group (cons_variables, fun_defs, ts) // ((cons_variables, fun_defs, ts) ---> "[(") ---> ")]"
@@ -1769,6 +1796,23 @@ where
 			CheckedType _
 				-> ts
 
+// MW0..
+	check_type_of_start_rule fd checked_fun_type error_admin
+		| not (isEmpty checked_fun_type.st_context)
+			= checkErrorWithIdentPos (newPosition fd.fun_symb fd.fun_pos) "must not be overloaded" error_admin
+		| isEmpty checked_fun_type.st_args
+			= error_admin
+		| length checked_fun_type.st_args > 1
+			= checkErrorWithIdentPos (newPosition fd.fun_symb fd.fun_pos) "should have arity 0 or 1" error_admin
+		= case checked_fun_type.st_args of
+			[]	-> error_admin
+			[{at_type=TB BT_World}] 
+				-> error_admin
+			[{at_type=TV _}]
+				-> error_admin
+			_	-> checkErrorWithIdentPos (newPosition fd.fun_symb fd.fun_pos) "argument must be of type World" error_admin
+// ..MW0
+
 instance <<< AttrCoercion
 where
 	(<<<) file {ac_demanded,ac_offered} = file <<< ac_demanded <<< '~' <<< ac_offered