typing: Make `TypeVisitor::mclassdef` non-nullable

[nit.git] / src / semantize / typing.nit

diff --git a/src/semantize/typing.nit b/src/semantize/typing.nit
index 7c1adf4..41b5eeb 100644 (file)
--- 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