model: add `MType::as_notnullable` to remove the `nullable` modifier

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/model/model.nit b/src/model/model.nit
index 8f92a87..f69f4c4 100644 (file)
--- a/src/model/model.nit
+++ b/src/model/model.nit
@@ -887,6 +887,16 @@ abstract class MType
                return res
        end
 
+       # Return the not nullable version of the type
+       # Is the type is already not nullable, then self is returned.
+       #
+       # Note: this just remove the `nullable` notation, but the result can still contains null.
+       # For instance if `self isa MNullType` or self is a a formal type bounded by a nullable type.
+       fun as_notnullable: MType
+       do
+               return self
+       end
+
        private var as_nullable_cache: nullable MType = null
 
 
@@ -1371,6 +1381,7 @@ class MNullableType
 
        redef fun need_anchor do return mtype.need_anchor
        redef fun as_nullable do return self
+       redef fun as_notnullable do return mtype
        redef fun resolve_for(mtype, anchor, mmodule, cleanup_virtual)
        do
                var res = self.mtype.resolve_for(mtype, anchor, mmodule, cleanup_virtual)