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<H1> 6.3 Subprogram Bodies</H1>
<DIV Class="Paranum"><FONT SIZE=-2>1</FONT></DIV>
<DIV Class="Normal"> A <FONT FACE="Arial, Helvetica">subprogram_body</FONT>
specifies the execution of a subprogram. </DIV>
<H4 ALIGN=CENTER>Syntax</H4>
<DIV Class="Paranum"><FONT SIZE=-2>2</FONT></DIV>
<DIV Class="SyntaxIndented"><FONT FACE="Arial, Helvetica">subprogram_body<A NAME="I2946"></A>
::= </FONT><BR>
<A NAME="I2947"></A><FONT FACE="Arial, Helvetica">subprogram_specification</FONT> <B>is</B><BR>
<A NAME="I2948"></A><FONT FACE="Arial, Helvetica">declarative_part</FONT><BR>
<B>begin</B><BR>
<A NAME="I2949"></A><FONT FACE="Arial, Helvetica">handled_sequence_of_statements</FONT><BR>
<B>end</B> [<A NAME="I2950"></A><FONT FACE="Arial, Helvetica">designator</FONT>];</DIV>
<DIV Class="Paranum"><FONT SIZE=-2>3</FONT></DIV>
<DIV Class="SyntaxIndented">If a <FONT FACE="Arial, Helvetica">designator</FONT>
appears at the end of a <FONT FACE="Arial, Helvetica">subprogram_body</FONT>,
it shall repeat the <FONT FACE="Arial, Helvetica">defining_designator</FONT>
of the <FONT FACE="Arial, Helvetica">subprogram_specification</FONT>.
</DIV>
<H4 ALIGN=CENTER>Legality Rules</H4>
<DIV Class="Paranum"><FONT SIZE=-2>4</FONT></DIV>
<DIV Class="Normal"> In contrast to other bodies, a <FONT FACE="Arial, Helvetica">subprogram_body</FONT>
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 <FONT FACE="Arial, Helvetica">subprogram_declaration</FONT>
or <FONT FACE="Arial, Helvetica">generic_subprogram_declaration</FONT>.
The profile of a <FONT FACE="Arial, Helvetica">subprogram_body</FONT>
that completes a declaration shall conform fully to that of the declaration.
<A NAME="I2951"></A></DIV>
<H4 ALIGN=CENTER>Static Semantics</H4>
<DIV Class="Paranum"><FONT SIZE=-2>5</FONT></DIV>
<DIV Class="Normal"> A <FONT FACE="Arial, Helvetica">subprogram_body</FONT>
is considered a declaration. It can either complete a previous declaration,
or itself be the initial declaration of the subprogram. </DIV>
<H4 ALIGN=CENTER>Dynamic Semantics</H4>
<DIV Class="Paranum"><FONT SIZE=-2>6</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2952"></A>The elaboration of a non-generic
<FONT FACE="Arial, Helvetica">subprogram_body</FONT> has no other effect
than to establish that the subprogram can from then on be called without
failing the Elaboration_Check. </DIV>
<DIV Class="Paranum"><FONT SIZE=-2>7</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2953"></A>The execution of a <FONT FACE="Arial, Helvetica">subprogram_body</FONT>
is invoked by a subprogram call. For this execution the <FONT FACE="Arial, Helvetica">declarative_part</FONT>
is elaborated, and the <FONT FACE="Arial, Helvetica">handled_sequence_of_statements</FONT>
is then executed. </DIV>
<H4 ALIGN=CENTER>Examples</H4>
<DIV Class="Paranum"><FONT SIZE=-2>8</FONT></DIV>
<DIV Class="Normal" Style="margin-bottom: 0.4em"> <I>Example of procedure
body:</I> </DIV>
<DIV Class="Paranum"><FONT SIZE=-2>9</FONT></DIV>
<DIV Class="Examples"><TT><B>procedure</B> Push(E : <B>in</B> Element_Type; S : <B>in</B> <B>out</B> Stack) <B>is</B><BR>
<B>begin</B><BR>
<B>if</B> S.Index = S.Size <B>then</B><BR>
<B>raise</B> Stack_Overflow;<BR>
<B>else</B><BR>
S.Index := S.Index + 1;<BR>
S.Space(S.Index) := E;<BR>
<B>end</B> <B>if</B>;<BR>
<B>end</B> Push;</TT></DIV>
<DIV Class="Paranum"><FONT SIZE=-2>10</FONT></DIV>
<DIV Class="Wide" Style="margin-bottom: 0.4em"> <I>Example of a function
body:</I> </DIV>
<DIV Class="Paranum"><FONT SIZE=-2>11</FONT></DIV>
<DIV Class="Examples"><TT><B>function</B> Dot_Product(Left, Right : Vector) <B>return</B> Real <B>is</B><BR>
Sum : Real := 0.0;<BR>
<B>begin</B><BR>
Check(Left'First = Right'First <B>and</B> Left'Last = Right'Last);<BR>
<B>for</B> J <B>in</B> Left'Range <B>loop</B><BR>
Sum := Sum + Left(J)*Right(J);<BR>
<B>end</B> <B>loop</B>;<BR>
<B>return</B> Sum;<BR>
<B>end</B> Dot_Product;</TT></DIV>
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