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<H1> 5.7 Exit Statements</H1>
<DIV Class="Paranum"><FONT SIZE=-2>1</FONT></DIV>
<DIV Class="Normal"> [An <FONT FACE="Arial, Helvetica">exit_statement</FONT>
is used to complete the execution of an enclosing <FONT FACE="Arial, Helvetica">loop_statement</FONT>;
the completion is conditional if the <FONT FACE="Arial, Helvetica">exit_statement</FONT>
includes a <FONT FACE="Arial, Helvetica">condition</FONT>.] </DIV>
<H4 ALIGN=CENTER>Syntax</H4>
<DIV Class="Paranum"><FONT SIZE=-2>2</FONT></DIV>
<DIV Class="SyntaxIndented"><FONT FACE="Arial, Helvetica">exit_statement<A NAME="I2989"></A>
::= </FONT><BR>
<B>exit</B> [<I>loop_</I><A NAME="I2990"></A><FONT FACE="Arial, Helvetica">name</FONT>] [<B>when</B> <A NAME="I2991"></A><FONT FACE="Arial, Helvetica">condition</FONT>];</DIV>
<H4 ALIGN=CENTER>Name Resolution Rules</H4>
<DIV Class="Paranum"><FONT SIZE=-2>3</FONT></DIV>
<DIV Class="Normal"> The <I>loop_</I><FONT FACE="Arial, Helvetica">name</FONT>,
if any, in an <FONT FACE="Arial, Helvetica">exit_statement</FONT> shall
resolve to denote a <FONT FACE="Arial, Helvetica">loop_statement</FONT>.
</DIV>
<H4 ALIGN=CENTER>Legality Rules</H4>
<DIV Class="Paranum"><FONT SIZE=-2>4</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2992"></A>Each <FONT FACE="Arial, Helvetica">exit_statement</FONT>
<I>applies to</I> a <FONT FACE="Arial, Helvetica">loop_statement</FONT>;
this is the <FONT FACE="Arial, Helvetica">loop_statement</FONT> being
exited. An <FONT FACE="Arial, Helvetica">exit_statement</FONT> with a
<FONT FACE="Arial, Helvetica">name</FONT> is only allowed within the
<FONT FACE="Arial, Helvetica">loop_statement</FONT> denoted by the <FONT FACE="Arial, Helvetica">name</FONT>,
and applies to that <FONT FACE="Arial, Helvetica">loop_statement</FONT>.
An <FONT FACE="Arial, Helvetica">exit_statement</FONT> without a <FONT FACE="Arial, Helvetica">name</FONT>
is only allowed within a <FONT FACE="Arial, Helvetica">loop_statement</FONT>,
and applies to the innermost enclosing one. An <FONT FACE="Arial, Helvetica">exit_statement</FONT>
that applies to a given <FONT FACE="Arial, Helvetica">loop_statement</FONT>
shall not appear within a body or <FONT FACE="Arial, Helvetica">accept_statement</FONT>,
if this construct is itself enclosed by the given <FONT FACE="Arial, Helvetica">loop_statement</FONT>.
</DIV>
<H4 ALIGN=CENTER>Dynamic Semantics</H4>
<DIV Class="Paranum"><FONT SIZE=-2>5</FONT></DIV>
<DIV Class="Normal"> <A NAME="I2993"></A>For the execution of an <FONT FACE="Arial, Helvetica">exit_statement</FONT>,
the <FONT FACE="Arial, Helvetica">condition</FONT>, if present, is first
evaluated. If the value of the <FONT FACE="Arial, Helvetica">condition</FONT>
is True, or if there is no <FONT FACE="Arial, Helvetica">condition</FONT>,
a transfer of control is done to complete the <FONT FACE="Arial, Helvetica">loop_statement</FONT>.
If the value of the <FONT FACE="Arial, Helvetica">condition</FONT> is
False, no transfer of control takes place. </DIV>
<DIV Class="NotesHeader"><FONT SIZE=-1>NOTES</FONT></DIV>
<DIV Class="Paranum"><FONT SIZE=-2>6</FONT></DIV>
<DIV Class="Notes"><FONT SIZE=-1>9 Several nested loops can
be exited by an <FONT FACE="Arial, Helvetica">exit_statement</FONT> that
names the outer loop. </FONT></DIV>
<H4 ALIGN=CENTER>Examples</H4>
<DIV Class="Paranum"><FONT SIZE=-2>7</FONT></DIV>
<DIV Class="Normal"> <I>Examples of loops with exit statements:</I>
</DIV>
<DIV Class="Paranum"><FONT SIZE=-2>8</FONT></DIV>
<DIV Class="Examples"><TT><B>for</B> N <B>in</B> 1 .. Max_Num_Items <B>loop</B><BR>
Get_New_Item(New_Item);<BR>
Merge_Item(New_Item, Storage_File);<BR>
<B>exit</B> <B>when</B> New_Item = Terminal_Item;<BR>
<B>end</B> <B>loop</B>;</TT></DIV>
<DIV Class="Paranum"><FONT SIZE=-2>9</FONT></DIV>
<DIV Class="Examples"><TT>Main_Cycle:<BR>
<B>loop</B><BR>
--<I> initial statements</I><BR>
<B>exit</B> Main_Cycle <B>when</B> Found;<BR>
--<I> final statements</I><BR>
<B>end</B> <B>loop</B> Main_Cycle;</TT></DIV>
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