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<title>Debugging with GDB: M2 Scope</title>
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<a name="M2-Scope"></a>
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Next: <a href="GDB_002fM2.html#GDB_002fM2" accesskey="n" rel="next">GDB/M2</a>, Previous: <a href="M2-Checks.html#M2-Checks" accesskey="p" rel="prev">M2 Checks</a>, Up: <a href="Modula_002d2.html#Modula_002d2" accesskey="u" rel="up">Modula-2</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<a name="The-Scope-Operators-_003a_003a-and-_002e"></a>
<h4 class="subsubsection">15.4.8.8 The Scope Operators <code>::</code> and <code>.</code></h4>
<a name="index-scope"></a>
<a name="index-_002e_002c-Modula_002d2-scope-operator"></a>
<a name="index-colon_002c-doubled-as-scope-operator"></a>
<a name="index-_003a_003a_002c-in-Modula_002d2"></a>
<p>There are a few subtle differences between the Modula-2 scope operator
(<code>.</code>) and the <small>GDB</small> scope operator (<code>::</code>). The two have
similar syntax:
</p>
<div class="smallexample">
<pre class="smallexample">
<var>module</var> . <var>id</var>
<var>scope</var> :: <var>id</var>
</pre></div>
<p>where <var>scope</var> is the name of a module or a procedure,
<var>module</var> the name of a module, and <var>id</var> is any declared
identifier within your program, except another module.
</p>
<p>Using the <code>::</code> operator makes <small>GDB</small> search the scope
specified by <var>scope</var> for the identifier <var>id</var>. If it is not
found in the specified scope, then <small>GDB</small> searches all scopes
enclosing the one specified by <var>scope</var>.
</p>
<p>Using the <code>.</code> operator makes <small>GDB</small> search the current scope for
the identifier specified by <var>id</var> that was imported from the
definition module specified by <var>module</var>. With this operator, it is
an error if the identifier <var>id</var> was not imported from definition
module <var>module</var>, or if <var>id</var> is not an identifier in
<var>module</var>.
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