X-Git-Url: http://nitlanguage.org

diff --git a/src/syntax/mmbuilder.nit b/src/syntax/mmbuilder.nit
index de5ccbe..ce875a8 100644
--- a/src/syntax/mmbuilder.nit
+++ b/src/syntax/mmbuilder.nit
@@ -23,7 +23,7 @@ import syntax_base
 
 # Class specialization hierarchy sorter
 private class CSHSorter
-special AbstractSorter[MMLocalClass]
+	super AbstractSorter[MMLocalClass]
 	redef fun compare(a, b)
 	do
 		return a.cshe.rank <=> b.cshe.rank
@@ -42,25 +42,29 @@ redef class MMSrcModule
 
 		# Create local classes and attach them to global classes
 		var mmbv = new ClassBuilderVisitor(tc, self)
-		mmbv.visit(node)
-		if tc.error_count > 0 then exit(1)
+		mmbv.enter_visit(node)
+		tc.check_errors
+
+		if mhe.direct_greaters.is_empty then
+			process_default_classes(tc)
+		end
 
 		# Import unrefined local classes and attach them to global classes
 		import_local_classes
 
 		# Resolve classes in super clauses
 		var mmbv1 = new ClassSpecializationBuilderVisitor(tc, self)
-		mmbv1.visit(node)
-		if tc.error_count > 0 then exit(1)
+		mmbv1.enter_visit(node)
+		tc.check_errors
 
 		# Compute specialization relation
 		for c in local_classes do
-			if visibility_for(c.global.intro.module) < c.global.visibility_level then
+			if visibility_for(c.global.intro.mmmodule) < c.global.visibility_level then
 				continue
 			end
 			c.compute_super_classes
 		end
-		if tc.error_count > 0 then exit(1)
+		tc.check_errors
 
 		# Class that we will process now are those in the hierarchy
 		# Its mean all the visible classes and their super-classes
@@ -75,34 +79,31 @@ redef class MMSrcModule
 		var mmbv1b = new ClassAncestorBuilder(tc, self)
 		for c in classes do
 			c.accept_class_visitor(mmbv1b)
-			if tc.error_count > 0 then exit(1)
+			tc.check_errors
 			c.compute_ancestors
 		end
 
 		# Check class conformity
-		var mmbv1b = new ClassVerifierVisitor(tc, self)
+		var mmbv1c = new ClassVerifierVisitor(tc, self)
 		for c in classes do
-			c.accept_class_visitor(mmbv1b)
+			c.accept_class_visitor(mmbv1c)
 		end
-		if tc.error_count > 0 then exit(1)
+		tc.check_errors
 
 		# Property inhritance and introduction
 		var mmbv2 = new PropertyBuilderVisitor(tc, self)
 		for c in classes do
-			# Inherit global properties
-			c.inherit_global_properties
-
 			# Global property introduction and redefinition 
 			c.accept_class_visitor(mmbv2)
 
 			# Default and inherited constructor if needed
-			if c isa MMSrcLocalClass and c.global.intro == c and not c.global.is_universal and not c.global.is_interface then
+			if c isa MMSrcLocalClass and c.global.intro == c and not c.global.is_enum and not c.global.is_interface then
 				c.process_default_constructors(mmbv2)
 			end
 
 			# Note that inherited unredefined property are processed on demand latter
 		end
-		if tc.error_count > 0 then exit(1)
+		tc.check_errors
 
 		# Property signature analysis and inheritance conformance
 		var mmbv3 = new PropertyVerifierVisitor(tc, self)
@@ -110,15 +111,24 @@ redef class MMSrcModule
 			c.accept_properties_visitor(mmbv3)
 		end
 
-		# Check inherited local properties
-		for c in classes do
-			for g in c.global_properties do
-				if visibility_for(g.intro.module) < g.visibility_level then continue
-				var p = c[g]
-			end
-		end
+		tc.check_errors
+	end
 
-		if tc.error_count > 0 then exit(1)
+	# Create some primitive default classes if they do not exists
+	fun process_default_classes(tc: ToolContext)
+	do
+		var name = once ("Object".to_symbol)
+		if not has_global_class_named(name) then
+			var c = new MMSrcLocalClass(self, name, null, 0)
+			c.new_global
+			src_local_classes[name] = c
+		end
+		name = once ("Bool".to_symbol)
+		if not has_global_class_named(name) then
+			var c = new MMSrcLocalClass(self, name, null, 0)
+			c.new_global
+			src_local_classes[name] = c
+		end
 	end
 end
 
@@ -137,16 +147,20 @@ end
 redef class MMSrcLocalClass
 	redef fun accept_class_visitor(v)
 	do
-		for n in nodes do
-			v.visit(n)
+		var n = node
+		while n != null do
+			v.enter_visit(n)
+			n = n.next_node
 		end
 	end
 
 	# Accept a class visitor (on class properties)
 	redef fun accept_properties_visitor(v)
 	do
-		for n in nodes do
-			v.visit(n)
+		var n = node
+		while n != null do
+			v.enter_visit(n)
+			n = n.next_node
 		end
 
 		for p in src_local_properties do
@@ -169,7 +183,7 @@ redef class MMSrcLocalClass
 		var super_inits = new ArraySet[MMLocalProperty]
 		var super_constructors = new ArraySet[MMGlobalProperty]
 		for sc in che.direct_greaters do
-			if sc.global.is_universal or sc.global.is_interface then continue
+			if sc.global.is_enum or sc.global.is_interface then continue
 			for gp in sc.global_properties do
 				if not gp.is_init then continue
 				super_constructors.add(gp)
@@ -207,7 +221,7 @@ redef class MMSrcLocalClass
 			var superclass: nullable MMLocalClass = null # This most specific non-mixin superclass (if any)
 
 			if supers.length > 1 then
-				v.error(nodes.first, "Error: Explicit constructor required in {self} since multiple inheritance of constructor is forbiden. Conflicting classes are {supers.join(", ")}. Costructors are {super_constructors.join(", ")}.")
+				v.error(node, "Error: Explicit constructor required in {self} since multiple inheritance of constructor is forbiden. Conflicting classes are {supers.join(", ")}. Costructors are {super_constructors.join(", ")}.")
 				return
 			else if supers.length == 1 then
 				superclass = supers.first
@@ -262,7 +276,7 @@ redef class MMLocalProperty
 end
 
 redef class MMImplicitInit
-	readable var _super_init: nullable MMLocalProperty = null
+	redef readable var _super_init: nullable MMLocalProperty = null
 	redef fun accept_property_visitor(v)
 	do
 		var base: nullable MMLocalProperty = null
@@ -297,14 +311,11 @@ end
 
 # Concrete NIT class specialization relation
 class MMSrcAncestor
-special MMAncestor
-	# The related AST node
-	readable var _node: ASuperclass
+	super MMAncestor
 	redef readable var _local_class: MMLocalClass
 
-	init(n: ASuperclass, c: MMLocalClass)
+	init(c: MMLocalClass)
 	do
-		_node = n
 		_local_class = c
 	end
 end
@@ -315,7 +326,7 @@ end
 # * Build the classes and attach them to global classes
 # * Collect generic formal parameters.
 private class ClassBuilderVisitor
-special AbsSyntaxVisitor
+	super AbsSyntaxVisitor
 	# Current class arity
 	readable writable var _local_class_arity: Int = 0
 
@@ -329,7 +340,7 @@ end
 # Another pass visitor for syntax analysis.
 # * Build ancertors (with only class informations not the type one)
 private class ClassSpecializationBuilderVisitor
-special AbsSyntaxVisitor
+	super AbsSyntaxVisitor
 	redef fun visit(n) do n.accept_class_specialization_builder(self)
 	init(tc, m) do super
 end
@@ -337,7 +348,7 @@ end
 # Another pass visitor for syntax analysis.
 # * Compute types in ancestors
 private class ClassAncestorBuilder
-special AbsSyntaxVisitor
+	super AbsSyntaxVisitor
 	redef fun visit(n) do n.accept_class_ancestor_builder(self)
 	init(tc, m) do super
 end
@@ -345,7 +356,7 @@ end
 # Another pass visitor for syntax analysis.
 # * Checks classes in regard to superclasses
 private class ClassVerifierVisitor
-special AbsSyntaxVisitor
+	super AbsSyntaxVisitor
 	redef fun visit(n) do n.accept_class_verifier(self)
 	init(tc, m) do super
 end
@@ -356,7 +367,7 @@ end
 # * Build local properties and attache them to global properties
 # * Attach bound to formal types
 private class PropertyBuilderVisitor
-special AbsSyntaxVisitor
+	super AbsSyntaxVisitor
 	redef fun visit(n) do n.accept_property_builder(self)
 	init(tc, m) do super
 end
@@ -364,7 +375,7 @@ end
 # Another pass pass visitor for syntax analysis.
 # * Check property conformance
 private class PropertyVerifierVisitor
-special AbsSyntaxVisitor
+	super AbsSyntaxVisitor
 
 	# The signature currently build
 	readable writable var _signature_builder: SignatureBuilder
@@ -381,10 +392,10 @@ end
 # Information about a signature currently build
 private class SignatureBuilder
 	# Current visited parameter types
-	readable writable var _params: Array[PParam] = new Array[PParam]
+	readable writable var _params: Array[AParam] = new Array[AParam]
 	
 	# Visited parameters without type information added
-	readable writable var _untyped_params: Array[PParam] = new Array[PParam]
+	readable writable var _untyped_params: Array[AParam] = new Array[AParam]
 
 	# Position of the current star parameter
 	readable writable var _vararg_rank: Int = -1
@@ -401,7 +412,7 @@ end
 
 ###############################################################################
 
-redef class PNode
+redef class ANode
 	private fun accept_class_builder(v: ClassBuilderVisitor) do accept_abs_syntax_visitor(v)
 	private fun accept_class_specialization_builder(v: ClassSpecializationBuilderVisitor) do accept_abs_syntax_visitor(v)
 	private fun accept_class_ancestor_builder(v: ClassAncestorBuilder) do accept_abs_syntax_visitor(v)
@@ -417,7 +428,7 @@ redef class AModule
 		# Import super-modules
 		var module_names_to_import = new Array[Symbol]
 		var module_visibility = new HashMap[Symbol, Int]
-		var no_import: nullable PImport = null
+		var no_import: nullable AImport = null
 		for i in n_imports do
 			var n = i.module_name
 			if n != null then
@@ -429,7 +440,7 @@ redef class AModule
 		end
 		if no_import != null then
 			if not module_names_to_import.is_empty then
-				tc.error("{no_import.locate}: Error: Top modules cannot import other modules.")
+				tc.error(no_import.location, "Error: Top modules cannot import other modules.")
 			end
 		else if module_names_to_import.is_empty then
 			var stdname = once "standard".to_symbol
@@ -447,23 +458,23 @@ redef class AModule
 	end
 end
 
-redef class APackagedecl
+redef class AModuledecl
 	redef fun accept_class_builder(v)
 	do
-		if n_id.to_symbol != v.module.name then
-			v.error(n_id, "Error: Package name missmatch between {v.module.name} and {n_id.to_symbol}")
+		if n_id.to_symbol != v.mmmodule.name then
+			v.error(n_id, "Error: Module name missmatch between {v.mmmodule.name} and {n_id.to_symbol}")
 		end
 	end
 end
 
-redef class PImport
+redef class AImport
 	# Imported module name (or null)
 	fun module_name: nullable Symbol is abstract
 
 	# Visibility level (intrude/public/private)
 	fun visibility_level: Int is abstract
 end
-redef class AImport
+redef class AStdImport
 	redef fun module_name
 	do
 		return n_id.to_symbol
@@ -480,7 +491,7 @@ redef class ANoImport
 	end
 end
 
-redef class PVisibility
+redef class AVisibility
 	# Visibility level
 	fun level: Int is abstract
 end
@@ -498,7 +509,7 @@ redef class AIntrudeVisibility
 end
 
 
-redef class PClassdef
+redef class AClassdef
 	redef fun local_class: MMSrcLocalClass do return _local_class.as(not null)
 	var _local_class: nullable MMSrcLocalClass
 
@@ -514,16 +525,19 @@ redef class PClassdef
 	redef fun accept_class_builder(v)
 	do
 		var local_class: MMSrcLocalClass
-		var mod = v.module
+		var mod = v.mmmodule
 		var local_classes = mod.src_local_classes
 		if (local_classes.has_key(name)) then
 			local_class = local_classes[name]
-			if self isa AClassdef then
+			if self isa AStdClassdef then
 				# If we are not a special implicit class then rant
-				v.error(self, "Error: A class {name} is already defined at line {local_class.nodes.first.first_token.line}.")
+				v.error(self, "Error: A class {name} is already defined at line {local_class.node.location.line_start}.")
 				return
 			end
-			local_class.nodes.add(self)
+			# Add the new node after the last node
+			var n = local_class.node
+			while n.next_node != null do n = n.next_node
+			n.next_node = self
 		else
 			local_class = new MMSrcLocalClass(mod, name, self, arity)
 			local_classes[name] = local_class
@@ -553,23 +567,23 @@ redef class PClassdef
 	end
 end
 
-redef class PClasskind
+redef class AClasskind
 	fun is_interface: Bool do return false
-	fun is_universal: Bool do return false
+	fun is_enum: Bool do return false
 	fun is_abstract: Bool do return false
 end
 
 redef class AInterfaceClasskind
 	redef fun is_interface do return true
 end
-redef class AUniversalClasskind
-	redef fun is_universal do return true
+redef class AEnumClasskind
+	redef fun is_enum do return true
 end
 redef class AAbstractClasskind
 	redef fun is_abstract do return true
 end
 
-redef class AClassdef
+redef class AStdClassdef
 	redef fun name
 	do
 		return n_id.to_symbol
@@ -587,7 +601,7 @@ redef class AClassdef
 			glob.visibility_level = visibility_level
 			glob.is_interface = n_classkind.is_interface
 			glob.is_abstract = n_classkind.is_abstract
-			glob.is_universal = n_classkind.is_universal
+			glob.is_enum = n_classkind.is_enum
 			if n_kwredef != null then
 				v.error(self, "Redef error: No class {name} is imported. Remove the redef keyword to define a new class.")
 			end
@@ -595,18 +609,18 @@ redef class AClassdef
 			for c in _local_class.cshe.direct_greaters do
 				var cg = c.global
 				if glob.is_interface then
-					if cg.is_universal then
-						v.error(self, "Special error: Interface {name} try to specialise universal class {c.name}.")
+					if cg.is_enum then
+						v.error(self, "Special error: Interface {name} try to specialise enum class {c.name}.")
 					else if not cg.is_interface then
 						v.error(self, "Special error: Interface {name} try to specialise class {c.name}.")
 					end
-				else if glob.is_universal then
-					if not cg.is_interface and not cg.is_universal then
-						v.error(self, "Special error: Universal class {name} try to specialise class {c.name}.")
+				else if glob.is_enum then
+					if not cg.is_interface and not cg.is_enum then
+						v.error(self, "Special error: Enum class {name} try to specialise class {c.name}.")
 					end
 				else
-					if cg.is_universal then
-						v.error(self, "Special error: Class {name} try to specialise universal class {c.name}.")
+					if cg.is_enum then
+						v.error(self, "Special error: Class {name} try to specialise enum class {c.name}.")
 					end
 				end
 
@@ -616,7 +630,7 @@ redef class AClassdef
 
 		# Redef
 
-		glob.check_visibility(v, self, v.module)
+		glob.check_visibility(v, self, v.mmmodule)
 		if n_kwredef == null then
 			v.error(self, "Redef error: {name} is an imported class. Add the redef keyword to refine it.")
 			return
@@ -629,7 +643,7 @@ redef class AClassdef
 		if 
 			not glob.is_interface and n_classkind.is_interface or
 			not glob.is_abstract and n_classkind.is_abstract or
-			not glob.is_universal and n_classkind.is_universal
+			not glob.is_enum and n_classkind.is_enum
 		then
 			v.error(self, "Redef error: cannot change kind of class {name}.")
 		end
@@ -655,26 +669,14 @@ redef class ATopClassdef
 	end
 end
 
-class MMSrcTypeFormalParameter
-special MMTypeFormalParameter
-	# The associated node
-	readable var _node: AFormaldef 
-
-	init(name: Symbol, pos: Int, local_class: MMLocalClass, n: AFormaldef)
-	do
-		super(name, pos, local_class)
-		_node = n
-	end
-end
-
 redef class AFormaldef
 	# The associated formal generic parameter (MM entity)
-	var _formal: nullable MMSrcTypeFormalParameter
+	var _formal: nullable MMTypeFormalParameter
 
 	redef fun accept_class_builder(v)
 	do
 		var name = n_id.to_symbol
-		var formal_type = new MMSrcTypeFormalParameter(name, v.local_class_arity, v.local_class, self)
+		var formal_type = new MMTypeFormalParameter(name, v.local_class_arity, v.local_class)
 		_formal = formal_type
 		v.local_class_arity = v.local_class_arity + 1
 		v.local_class.register_formal(formal_type)
@@ -689,14 +691,14 @@ redef class AFormaldef
 		var o = c.global.intro
 		if c == o then
 			if n_type == null then
-				_formal.bound = v.module.type_any.as_nullable
+				_formal.bound = v.mmmodule.type_any.as_nullable
 			else
 				var stype = n_type.get_stype(v)
 				if stype == null then return
 				_formal.bound = stype
 			end
 		else
-			var ob = o.get_formal(_formal.position).bound.for_module(v.module)
+			var ob = o.get_formal(_formal.position).bound.for_module(v.mmmodule)
 			if n_type == null then
 				_formal.bound = ob
 			else
@@ -719,7 +721,7 @@ redef class ASuperclass
 		super
 		var c = n_type.get_local_class(v)
 		if c == null then return
-		var ancestor = new MMSrcAncestor(self, c)
+		var ancestor = new MMSrcAncestor(c)
 		_ancestor = ancestor
 		v.local_class.add_direct_parent(ancestor)
 	end
@@ -738,7 +740,7 @@ redef class ASuperclass
 	end
 end
 
-redef class PPropdef
+redef class APropdef
 	# Process and check properties of the property.
 	# * Distinguish inits and methods
 	# * Inherit or check visibility.
@@ -770,14 +772,14 @@ redef class PPropdef
 		if glob.is_attribute then
 			if gbc.is_interface then
 				v.error(self, "Error: Attempt to define attribute {prop} in the interface {prop.local_class}.")
-			else if gbc.is_universal then
-				v.error(self, "Error: Attempt to define attribute {prop} in the universal class {prop.local_class}.")
+			else if gbc.is_enum then
+				v.error(self, "Error: Attempt to define attribute {prop} in the enum class {prop.local_class}.")
 			end
 		else if glob.is_init then
 			if gbc.is_interface then
 				v.error(self, "Error: Attempt to define a constructor {prop} in the class {prop.local_class}.")
-			else if gbc.is_universal then
-				v.error(self, "Error: Attempt to define a constructor {prop} in the universal {prop.local_class}.")
+			else if gbc.is_enum then
+				v.error(self, "Error: Attempt to define a constructor {prop} in the enum {prop.local_class}.")
 			end
 		end
 		if prop.signature == null then
@@ -806,7 +808,6 @@ redef class PPropdef
 
 			if s == null then
 				if v.signature_builder.params.length != isig.arity then
-					#prop.node.printl("v.params.length {v.params.length} != isig.arity {isig.arity} ; {prop.full_name} vs {ip.full_name}")
 					return
 				end
 				for p in v.signature_builder.params do
@@ -841,10 +842,12 @@ redef class PPropdef
 		end
 
 		var s = prop.signature
-		#print "process {prop.local_class.module}::{prop.local_class}::{prop} from global {prop.global.local_property.local_class.module}::{prop.global.local_property.local_class}::{prop.global.local_property}"
+		#print "process {prop.local_class.mmmodule}::{prop.local_class}::{prop} from global {prop.global.local_property.local_class.mmmodule}::{prop.global.local_property.local_class}::{prop.global.local_property}"
 		for i in prop.prhe.direct_greaters do
 			var ip = i.local_class[prop.global]
-			var isig = i.signature.adaptation_to(v.local_class.get_type)
+			var isig = i.signature
+			if isig == null then break # previous signature is invalid
+			isig = isig.adaptation_to(v.local_class.get_type)
 
 			if s == null then
 				#print "{prop.full_name} inherits signature from {ip.full_name}"
@@ -880,9 +883,9 @@ redef class PPropdef
 			if s.arity != isig.arity then
 				v.error(self, "Redef error: {prop.local_class}::{prop} redefines {ip.local_class}::{ip} with {isig.arity} parameter(s).")
 			else
-				for i in [0..s.arity[ do
-					if s[i] != isig[i] then
-						v.error(self, "Redef error: Expected {isig[i]} (as in {ip.local_class}::{ip}), got {s[i]} in {prop.local_class}::{prop}.")
+				for j in [0..s.arity[ do
+					if s[j] != isig[j] then
+						v.error(self, "Redef error: Expected {isig[j]} (as in {ip.local_class}::{ip}), got {s[j]} in {prop.local_class}::{prop}.")
 					end
 				end
 			end
@@ -907,7 +910,7 @@ redef class PPropdef
 		if visibility_level != 1 and glob.visibility_level != visibility_level then
 			v.error(self, "Redef error: {prop.local_class}::{prop} redefinition cannot change visibility.")
 		end
-		glob.check_visibility(v, self, v.module, true)
+		glob.check_visibility(v, self, v.mmmodule, true)
 	end
 end
 
@@ -920,20 +923,33 @@ redef class AAttrPropdef
 	redef fun accept_property_builder(v)
 	do
 		super
-		var name = n_id.to_symbol
+		var name: Symbol
+		if n_id != null then
+			name = n_id.to_symbol
+		else
+			name = ("@" + n_id2.text).to_symbol
+		end
 		var lc = v.local_class
 		var prop = new MMSrcAttribute(name, lc, self)
 		_prop = prop
 		v.local_class.add_src_local_property(v, prop)
 
-		if n_readable != null then
-			name = n_id.text.substring_from(1).to_symbol
+		if n_readable != null or n_id == null then
+			if n_id != null then
+				name = n_id.text.substring_from(1).to_symbol
+			else
+				name = n_id2.to_symbol
+			end
 			var readmethod = new MMReadImplementationMethod(name, lc, self)
 			_readmethod = readmethod
 			v.local_class.add_src_local_property(v, readmethod)
 		end
-		if n_writable != null then
-			name = (n_id.text.substring_from(1) + "=").to_symbol
+		if n_writable != null or n_id == null then
+			if n_id != null then
+				name = (n_id.text.substring_from(1) + "=").to_symbol
+			else
+				name = (n_id2.text + "=").to_symbol
+			end
 			var writemethod = new MMWriteImplementationMethod(name, lc, self)
 			_writemethod = writemethod
 			v.local_class.add_src_local_property(v, writemethod)
@@ -948,7 +964,7 @@ redef class AAttrPropdef
 			var t0 = n_type.get_stype(v)
 			if t0 != null then t = t0 else return
 		else
-			v.error(self, "Not yet implemented: Attribute definition {_prop.local_class}::{_prop} requires an explicit type.")
+			v.error(self, "Not yet implemented: Attribute definition {prop.local_class}::{prop} requires an explicit type.")
 			return
 		end
 
@@ -956,17 +972,21 @@ redef class AAttrPropdef
 		var signature = new MMSignature(new Array[MMType], t, v.local_class.get_type)
 		prop.signature = signature
 		var visibility_level = n_visibility.level
-		process_and_check(v, prop, n_kwredef != null, visibility_level)
-		if n_readable != null then
+		process_and_check(v, prop, n_id != null and n_kwredef != null, visibility_level)
+		if n_readable != null or n_id == null then
 			var m = _readmethod.as(not null)
 			m.signature = signature
-			process_and_check(v, m, n_readable.n_kwredef != null, visibility_level)
+			process_and_check(v, m, (n_readable != null and n_readable.n_kwredef != null) or (n_id == null and n_kwredef != null), visibility_level)
 			n_type.check_visibility(v, m)
 		end
-		if n_writable != null then
+		if n_writable != null or n_id == null then
 			var m = _writemethod.as(not null)
 			m.signature = new MMSignature(new Array[MMType].with_items(t), null, v.local_class.get_type)
-			process_and_check(v, m, n_writable.n_kwredef != null, visibility_level)
+			var vl = visibility_level
+			if n_id == null then
+				if n_writable == null then vl = 3 else vl = n_writable.n_visibility.level # write accessor has a specific visibility
+			end
+			process_and_check(v, m, n_writable != null and n_writable.n_kwredef != null, vl)
 			n_type.check_visibility(v, m)
 		end
 	end
@@ -1001,7 +1021,7 @@ redef class AMethPropdef
 			# FIXME: Add the 'unary' keyword
 			if n_methid.name == (once "-".to_symbol) then
 				var ns = n_signature
-				if ns isa ASignature and ns.n_params.length == 0 then
+				if ns != null and ns.n_params.length == 0 then
 					name = once "unary -".to_symbol
 				end
 			end
@@ -1049,6 +1069,21 @@ redef class AMainMethPropdef
 	end
 end
 
+redef class AExternMethPropdef
+	redef fun accept_property_verifier(v)
+	do
+		super # Compute signature
+		var ename: String
+		if n_extern != null then
+			ename = n_extern.text
+			ename = ename.substring(1, ename.length-2)
+		else
+			ename = "{method.mmmodule.name}_{method.local_class.name}_{method.local_class.name}_{method.name}_{method.signature.arity}"
+		end
+		method.extern_name = ename
+	end
+end
+
 redef class ATypePropdef
 	redef fun prop do return _prop.as(not null)
 	var _prop: nullable MMSrcTypeProperty
@@ -1081,7 +1116,7 @@ end
 
 # Visitor used to build a full method name from multiple tokens
 private class MethidAccumulator
-special Visitor
+	super Visitor
 	readable var _name: Buffer = new Buffer
 	redef fun visit(n)
 	do
@@ -1093,24 +1128,19 @@ special Visitor
 	end
 end
 
-redef class PMethid
+redef class AMethid
 	# Method name
 	readable var _name: nullable Symbol 
 
 	redef fun accept_property_builder(v)
 	do
 		var accumulator = new MethidAccumulator
-		accumulator.visit(self)
+		accumulator.enter_visit(self)
 		_name = accumulator.name.to_s.to_symbol
 		super
 	end
 end
 
-redef class PSignature
-	# Check that visibilities of types in the signature are compatible with the visibility of the property.
-	fun check_visibility(v: AbsSyntaxVisitor, p: MMLocalProperty) is abstract
-end
-
 redef class ASignature
 	redef fun accept_property_verifier(v)
 	do
@@ -1145,7 +1175,8 @@ redef class ASignature
 		end
 	end
 
-	redef fun check_visibility(v, p)
+	# Check that visibilities of types in the signature are compatible with the visibility of the property.
+	fun check_visibility(v: AbsSyntaxVisitor, p: MMLocalProperty)
 	do
 		if p.global.visibility_level >= 3 then return
 		for n in n_params do
@@ -1155,7 +1186,7 @@ redef class ASignature
 	end
 end
 
-redef class PParam
+redef class AParam
 	redef readable var _position: Int = 0
 
 	redef fun variable: ParamVariable do return _variable.as(not null)
@@ -1168,7 +1199,7 @@ redef class PParam
 	do
 		super
 		_position = v.signature_builder.params.length
-		_variable = new ParamVariable(n_id.to_symbol, self)
+		_variable = new ParamVariable(n_id.to_symbol, n_id)
 		v.signature_builder.params.add(self)
 		v.signature_builder.untyped_params.add(self)
 		if n_type != null then
@@ -1193,14 +1224,12 @@ redef class PParam
 		end
 	end
 
-	fun is_vararg: Bool is abstract
-end
-
-redef class AParam
-	redef fun is_vararg do return n_dotdotdot != null
+	fun is_vararg: Bool do return n_dotdotdot != null
 end
 
 redef class AClosureDecl
+	redef readable var _position: Int = 0
+
 	redef fun variable: ClosureVariable do return _variable.as(not null)
 	var _variable: nullable ClosureVariable
 
@@ -1221,24 +1250,28 @@ redef class AClosureDecl
 		end
 
 		# Add the finalizer to the closure signature
-		var finalize_sig = new MMSignature(new Array[MMType], null, v.module.type_any) # FIXME should be no receiver
-		var finalizer_clos = new MMClosure(finalize_sig, false, true)
+		var finalize_sig = new MMSignature(new Array[MMType], null, v.mmmodule.type_any) # FIXME should be no receiver
+		var finalizer_clos = new MMClosure(once ("break".to_symbol), finalize_sig, false, true)
 		sig.closures.add(finalizer_clos)
 
-		var clos = new MMClosure(sig, n_kwbreak != null, n_expr != null)
+		var name = n_id.to_symbol
+		var clos = new MMClosure(name, sig, n_kwbreak != null, n_expr != null)
+		for c in old_signature_builder.closure_decls do
+			if c.n_id.to_symbol == name then
+				v.error(n_id, "A closure '!{name}' already defined at {c.n_id.location.relative_to(n_id.location)}.")
+				return
+			end
+		end
 		v.signature_builder = old_signature_builder
+		_position = old_signature_builder.closure_decls.length
 		old_signature_builder.closure_decls.add(self)
-		_variable = new ClosureVariable(n_id.to_symbol, self, clos)
+		_variable = new ClosureVariable(n_id.to_symbol, n_id, clos)
 	end
 end
 
-redef class PType
-	# Check that visibilities of types in the signature are compatible with the visibility of the property.
-	private fun check_visibility(v: AbsSyntaxVisitor, p: MMLocalProperty) is abstract
-end
-
 redef class AType
-	redef fun check_visibility(v, p)
+	# Check that visibilities of types in the signature are compatible with the visibility of the property.
+	private fun check_visibility(v: AbsSyntaxVisitor, p: MMLocalProperty)
 	do
 		if p.global.visibility_level >= 3 then return
 		var t = get_stype(v)
@@ -1253,7 +1286,7 @@ redef class AType
 	end
 end
 
-redef class PExpr
+redef class AExpr
 	redef fun accept_class_builder(v) do end
 	redef fun accept_property_builder(v) do end
 	redef fun accept_property_verifier(v) do end