6.3 Subprogram Bodies
A subprogram_body specifies the execution of a subprogram.
subprogram_body ::= subprogram_specification is declarative_part begin handled_sequence_of_statements end [designator];
If a designator appears at the end of a subprogram_body, it shall repeat the defining_designator of the subprogram_specification.
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.
A subprogram_body is considered a declaration. It can either complete a previous declaration, or itself be the initial declaration of the subprogram.
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.
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.
Example of procedure body:
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;
Example of a function body:
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;
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Copyright © 2000 The MITRE Corporation, Inc. Ada Reference Manual