6.3 Subprogram Bodies

1. A subprogram_body specifies the execution of a subprogram.
   Syntax
   

2. subprogram_body ::=
      subprogram_specification is
         declarative_part
      begin
         handled_sequence_of_statements
      end [designator];
   

   1. If a designator appears at the end of a subprogram_body, it shall repeat the defining_designator of the subprogram_specification.

1. In contrast to other bodies, a subprogram_body need not be the completion of a previous declaration, in which case the body declares the subprogram. If the body is a completion, it shall be the completion of a subprogram_declaration or generic_subprogram_declaration. The profile of a subprogram_body that completes a declaration shall conform fully to that of the declaration.
   Static Semantics
   
2. A subprogram_body is considered a declaration. It can either complete a previous declaration, or itself be the initial declaration of the subprogram.
   Dynamic Semantics
   
3. The elaboration of a non-generic subprogram_body has no other effect than to establish that the subprogram can from then on be called without failing the Elaboration_Check.
4. The execution of a subprogram_body is invoked by a subprogram call. For this execution the declarative_part is elaborated, and the handled_sequence_of_statements is then executed.
   Examples
   
5. Example of procedure body:

6. procedure Push(E : in Element_Type; S : in out Stack) is
   begin
      if S.Index = S.Size then
         raise Stack_Overflow;
      else
         S.Index := S.Index + 1;
         S.Space(S.Index) := E;
      end if;
   end Push;
   

7. Example of a function body:

8. function Dot_Product(Left, Right : Vector) return Real is
      Sum : Real := 0.0;
   begin
      Check(Left'First = Right'First and Left'Last = Right'Last);
      for J in Left'Range loop
         Sum := Sum + Left(J)*Right(J);
      end loop;
      return Sum;
   end Dot_Product;
   

• 6.3.1: Conformance Rules
• 6.3.2: Inline Expansion of Subprograms

Go to the first, previous, next, last section, table of contents.