typing: advice if a receiver is nullable

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

diff --git a/src/semantize/typing.nit b/src/semantize/typing.nit
index f21ade7..10edaf1 100644 (file)
--- a/src/semantize/typing.nit
+++ b/src/semantize/typing.nit
@@ -301,15 +301,9 @@ private class TypeVisitor
 
                #debug("recv: {recvtype} (aka {unsafe_type})")
                if recvtype isa MNullType then
-                       # `null` only accepts some methods of object.
-                       if name == "==" or name == "!=" or name == "is_same_instance" then
-                               var objclass = get_mclass(node, "Object")
-                               if objclass == null then return null # Forward error
-                               unsafe_type = objclass.mclass_type
-                       else
-                               self.error(node, "Error: method `{name}` called on `null`.")
-                               return null
-                       end
+                       var objclass = get_mclass(node, "Object")
+                       if objclass == null then return null # Forward error
+                       unsafe_type = objclass.mclass_type
                end
 
                var mproperty = self.try_get_mproperty_by_name2(node, unsafe_type, name)
@@ -331,6 +325,14 @@ private class TypeVisitor
 
                assert mproperty isa MMethod
 
+               # `null` only accepts some methods of object.
+               if recvtype isa MNullType and not mproperty.is_null_safe then
+                       self.error(node, "Error: method `{name}` called on `null`.")
+                       return null
+               else if unsafe_type isa MNullableType and not mproperty.is_null_safe then
+                       modelbuilder.advice(node, "call-on-nullable", "Warning: method call on a nullable receiver `{recvtype}`.")
+               end
+
                if is_toplevel_context and recv_is_self and not mproperty.is_toplevel then
                        error(node, "Error: `{name}` is not a top-level method, thus need a receiver.")
                end
@@ -427,9 +429,39 @@ private class TypeVisitor
                var map = new SignatureMap
 
                var setted = args.length - msignature.min_arity
+
+               # First, handle named arguments
+               for i in [0..args.length[ do
+                       var e = args[i]
+                       if not e isa ANamedargExpr then continue
+                       var name = e.n_id.text
+                       var param = msignature.mparameter_by_name(name)
+                       if param == null then
+                               modelbuilder.error(e.n_id, "Error: no parameter `{name}` for `{mproperty}{msignature}`.")
+                               return null
+                       end
+                       if not param.is_default then
+                               modelbuilder.error(e, "Error: parameter `{name}` is not optional for `{mproperty}{msignature}`.")
+                               return null
+                       end
+                       var idx = msignature.mparameters.index_of(param)
+                       var prev = map.map.get_or_null(idx)
+                       if prev != null then
+                               modelbuilder.error(e, "Error: parameter `{name}` already associated with argument #{prev} for `{mproperty}{msignature}`.")
+                               return null
+                       end
+                       map.map[idx] = i
+                       setted -= 1
+                       e.mtype = self.visit_expr_subtype(e.n_expr, param.mtype)
+               end
+
+               # Second, associate remaining parameters
                var vararg_decl = args.length - msignature.arity
                var j = 0
                for i in [0..msignature.arity[ do
+                       # Skip parameters associated by name
+                       if map.map.has_key(i) then continue
+
                        var param = msignature.mparameters[i]
                        if param.is_default then
                                if setted > 0 then
@@ -438,6 +470,9 @@ private class TypeVisitor
                                        continue
                                end
                        end
+
+                       # Search the next free argument: skip named arguments since they are already associated
+                       while args[j] isa ANamedargExpr do j += 1
                        var arg = args[j]
                        map.map[i] = j
                        j += 1
@@ -450,6 +485,8 @@ private class TypeVisitor
                        var paramtype = param.mtype
                        self.visit_expr_subtype(arg, paramtype)
                end
+
+               # Third, check varargs
                if vararg_rank >= 0 then
                        var paramtype = msignature.mparameters[vararg_rank].mtype
                        var first = args[vararg_rank]