var res = v.compile_callsite(callsite, args)
if is_safe then
if res != null then
- var orig_res = res
+ # `callsite.mpropdef` may reference a method whose
+ # return type is a primitive type in C. If it is
+ # the case, we must convert the primitive type to
+ # a `val*` to support nullable assignment.
+ # Autobox's job is to convert primitive type to
+ # nullable type, eg from `Int` to `nullable `Int`.
+ # The target type reside in `self.mtype`.
+ var original_res = v.autobox(res, self.mtype.as(not null))
+
+ # Here we must create a new_var in case the original
+ # type is not nullable. We can't call `autobox` to
+ # convert a complex type to its nullable version.
+ # eg if we have a type `A`, calling autobox like
+ # `autobox(A, nullable A)` will return `A` since
+ # `A` and `nullable A` have the same primitive
+ # type. The nullable qualifier is only used at
+ # compile time to add appropriate null checks.
res = v.new_var(self.mtype.as(not null))
- v.add("{res} = {orig_res};")
+ v.add("{res} = {original_res};")
v.add("\} else \{")
v.add("{res} = NULL;")
end
--- /dev/null
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+redef class Int
+ fun foo do print self
+end
+
+class A
+ var x: Int
+end
+
+class B
+ var a: nullable A = null
+end
+
+class C
+ var x: Int
+ var c: nullable C = null
+end
+
+class D
+ var x: nullable Int
+ var d: nullable D = null
+end
+
+var b = new B
+
+#alt1#b.a?.x.foo
+
+var a = new A(10)
+
+b.a = a
+print "b.a.x: {b.a?.x or else "nothing"}"
+
+var c1 = new C(1)
+var c2 = new C(10)
+var c3 = new C(100)
+c1.c = c2
+c2.c = c3
+
+print c1.c?.c?.x or else "null"
+print c1.c?.c?.c or else "null"
+
+var d1 = new D(1)
+var d2 = new D(10)
+var d3 = new D(null)
+
+d1.d = d2
+d2.d = d3
+
+print d1.d?.x or else "null"
+print d1.d?.d?.x or else "null"