| Message ID | 20141017091132.GA30045@adacore.com |
|---|---|
| State | New |
| Headers | show |
Index: sem_ch5.adb =================================================================== --- sem_ch5.adb (revision 216367) +++ sem_ch5.adb (working copy) @@ -1838,6 +1838,17 @@ else Typ := Etype (Iter_Name); + + -- Verify that the expression produces an iterator. + + if not Of_Present (N) and then not Is_Iterator (Typ) + and then not Is_Array_Type (Typ) + and then No (Find_Aspect (Typ, Aspect_Iterable)) + then + Error_Msg_N + ("expect object that implements iterator interface", + Iter_Name); + end if; end if; -- Protect against malformed iterator
This patch improves the error message on an iterator specification whose name is a function call that does not yield a type that implements an iterator interface. Compiling try_containers.adb must yield: try_containers.adb:17:18: expect object that implements iterator interface -- with Ada.Text_Io; use Ada.Text_Io; with Ada.Containers.Vectors; procedure Try_Containers is package Integer_Vectors is new Ada.Containers.Vectors (Natural, Integer); use Integer_Vectors; A : Vector := To_Vector (1, 10); begin Loop_1 : for Element of A loop Put_Line ("A (i) => " & Integer'Image (Element)); -- can't do Element := 2; end loop Loop_1; Loop_2 : for Cursor in First (A) loop -- oops! should be: -- for Cursor in Iterate (A) loop Put_Line ("A (I) => " & Integer'Image (Element (Cursor))); Replace_Element (A, Cursor, 2); Reference (A, Cursor) := 2; end loop Loop_2; end Try_Containers; Tested on x86_64-pc-linux-gnu, committed on trunk 2014-10-17 Ed Schonberg <schonberg@adacore.com> * sem_ch5.adb (Analyze_Iterator_Specification): If the domain of iteration is given by an expression that is not an array type, verify that its type implements an iterator iterface.