- A subprogram_renaming_declaration can serve as the completion of a
subprogram_declaration; such a renaming_declaration is called a
renaming-as-body. A subprogram_renaming_declaration that is not a completion
is called a renaming-as-declaration, and is used to rename a subprogram
(possibly an enumeration literal) or an entry.
subprogram_renaming_declaration ::= subprogram_specification renames callable_entity_name;
Name Resolution Rules
- The expected profile for the callable_entity_name is the profile given in
- The profile of a renaming-as-declaration shall be mode-conformant with
that of the renamed callable entity.
- The profile of a renaming-as-body shall be subtype-conformant with that
of the renamed callable entity, and shall conform fully to that of the
declaration it completes. If the renaming-as-body completes that declaration
before the subprogram it declares is frozen, the subprogram it declares takes
its convention from the renamed subprogram; otherwise the convention of the
renamed subprogram shall not be Intrinsic.
- A name that denotes a formal parameter of the subprogram_specification is
not allowed within the callable_entity_name.
- A renaming-as-declaration declares a new view of the renamed entity. The
profile of this new view takes its subtypes, parameter modes, and calling
convention from the original profile of the callable entity, while taking the
formal parameter names and default_expressions from the profile given in the
subprogram_renaming_declaration. The new view is a function or procedure,
never an entry.
- For a call on a renaming of a dispatching subprogram that is overridden,
if the overriding occurred before the renaming, then the body executed is
that of the overriding declaration, even if the overriding declaration is not
visible at the place of the renaming; otherwise, the inherited or predefined
subprogram is called.
(11) A procedure can only be renamed as a procedure. A function whose defining_designator
is either an identifier or an operator_symbol can be renamed with either
an identifier or an operator_symbol; for renaming as an operator, the subprogram
specification given in the renaming_declaration is subject to the rules
given in 6.6 for operator declarations. Enumeration
literals can be renamed as functions; similarly, attribute_references that
denote functions (such as references to Succ and Pred) can be renamed as
functions. An entry can only be renamed as a procedure; the new name is
only allowed to appear in contexts that allow a procedure name. An entry
of a family can be renamed, but an entry family cannot be renamed as a whole.
(12) The operators of the root numeric types cannot be renamed because
the types in the profile are anonymous, so the corresponding
specifications cannot be written; the same holds for certain attributes,
such as Pos.
(13) Calls with the new name of a renamed entry are procedure_call_statements and are not allowed at places where the syntax requires an
entry_call_statement in conditional_ and timed_entry_calls, nor in an
asynchronous_select; similarly, the Count attribute is not available for
the new name.
(14) The primitiveness of a renaming-as-declaration is determined by its
profile, and by where it occurs, as for any declaration of (a view of) a
subprogram; primitiveness is not determined by the renamed view. In
order to perform a dispatching call, the subprogram name has to denote a
primitive subprogram, not a non-primitive renaming of a primitive
- Examples of subprogram renaming declarations:
procedure My_Write(C : in Character) renames Pool(K).Write; -- see 4.1.3
function Real_Plus(Left, Right : Real ) return Real renames "+";
function Int_Plus (Left, Right : Integer) return Integer renames "+";
function Rouge return Color renames Red; -- see 3.5.1
function Rot return Color renames Red;
function Rosso return Color renames Rouge;
function Next(X : Color) return Color renames Color'Succ; -- see 3.5.1
- Example of a subprogram renaming declaration with new parameter names:
function "*" (X,Y : Vector) return Real renames Dot_Product; -- see 6.1
- Example of a subprogram renaming declaration with a new default
function Minimum(L : Link := Head) return Cell renames Min_Cell; -- see 6.1
-- Email comments, additions, corrections, gripes, kudos, etc. to:
Magnus Kempe -- Magnus.Kempe@di.epfl.ch
Page last generated: 95-03-12