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

diff --git a/src/semantize/typing.nit b/src/semantize/typing.nit
index 7c1adf4..41b5eeb 100644
--- a/src/semantize/typing.nit
+++ b/src/semantize/typing.nit
@@ -43,10 +43,10 @@ private class TypeVisitor
 	var anchor: nullable MClassType = null
 
 	# The analyzed mclassdef
-	var mclassdef: nullable MClassDef = null
+	var mclassdef: MClassDef is noinit
 
 	# The analyzed property
-	var mpropdef: nullable MPropDef
+	var mpropdef: MPropDef
 
 	var selfvariable = new Variable("self")
 
@@ -59,33 +59,24 @@ private class TypeVisitor
 	init
 	do
 		var mpropdef = self.mpropdef
+		var mclassdef = mpropdef.mclassdef
+		self.mclassdef = mclassdef
+		self.anchor = mclassdef.bound_mtype
 
-		if mpropdef != null then
-			self.mpropdef = mpropdef
-			var mclassdef = mpropdef.mclassdef
-			self.mclassdef = mclassdef
-			self.anchor = mclassdef.bound_mtype
-
-			var mclass = mclassdef.mclass
+		var mclass = mclassdef.mclass
 
-			var selfvariable = new Variable("self")
-			self.selfvariable = selfvariable
-			selfvariable.declared_type = mclass.mclass_type
+		var selfvariable = new Variable("self")
+		self.selfvariable = selfvariable
+		selfvariable.declared_type = mclass.mclass_type
 
-			var mprop = mpropdef.mproperty
-			if mprop isa MMethod and mprop.is_new then
-				is_toplevel_context = true
-			end
+		var mprop = mpropdef.mproperty
+		if mprop isa MMethod and mprop.is_new then
+			is_toplevel_context = true
 		end
 	end
 
 	fun anchor_to(mtype: MType): MType
 	do
-		var anchor = anchor
-		if anchor == null then
-			assert not mtype.need_anchor
-			return mtype
-		end
 		return mtype.anchor_to(mmodule, anchor)
 	end
 
@@ -580,7 +571,16 @@ private class TypeVisitor
 				return mtypes.first
 			else
 				var res = merge_types(node,mtypes)
-				if res == null then res = variable.declared_type
+				if res == null then
+					res = variable.declared_type
+					# Try to fallback to a non-null version
+					if res != null and can_be_null(res) then do
+						for t in mtypes do
+							if t != null and can_be_null(t) then break label
+						end
+						res = res.as_notnull
+					end label
+				end
 				return res
 			end
 		end
@@ -736,7 +736,7 @@ end
 class CallSite
 	super MEntity
 
-	redef var location: Location
+	redef var location
 
 	# The static type of the receiver (possibly unresolved)
 	var recv: MType
@@ -781,11 +781,13 @@ class CallSite
 	fun dump_info(v: ASTDump): String do
 		return "{recv}.{mpropdef}{msignature}"
 	end
+
+	redef fun mdoc_or_fallback do return mproperty.intro.mdoc
 end
 
 redef class Variable
 	# The declared type of the variable
-	var declared_type: nullable MType is writable
+	var declared_type: nullable MType = null is writable
 
 	# Was the variable type-adapted?
 	# This is used to speedup type retrieval while it remains `false`
@@ -1788,9 +1790,16 @@ redef class AIsaExpr
 			#var to = if mtype != null then mtype.to_s else "invalid"
 			#debug("adapt {variable}: {from} -> {to}")
 
-			# Do not adapt if there is no information gain (i.e. adapt to a supertype)
-			if mtype == null or orig == null or not v.is_subtype(orig, mtype) then
-				self.after_flow_context.when_true.set_var(v, variable, mtype)
+			var thentype = v.intersect_types(self, orig, mtype)
+			if thentype != orig then
+				self.after_flow_context.when_true.set_var(v, variable, thentype)
+				#debug "{variable}:{orig or else "?"} isa {mtype or else "?"} -> then {thentype or else "?"}"
+			end
+
+			var elsetype = v.diff_types(self, orig, mtype)
+			if elsetype != orig then
+				self.after_flow_context.when_false.set_var(v, variable, elsetype)
+				#debug "{variable}:{orig or else "?"} isa {mtype or else "?"} -> else {elsetype or else "?"}"
 			end
 		end