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<h5 class="subsubsection">23.3.3.20 Guile representation of lazy strings.</h5>

<p><a name="index-lazy-strings-in-guile-2804"></a><a name="index-g_t_003cgdb_003alazy_002dstring_003e-2805"></a>
A <dfn>lazy string</dfn> is a string whose contents is not retrieved or
encoded until it is needed.

   <p>A <code>&lt;gdb:lazy-string&gt;</code> is represented in <span class="sc">gdb</span> as an
<code>address</code> that points to a region of memory, an <code>encoding</code>
that will be used to encode that region of memory, and a <code>length</code>
to delimit the region of memory that represents the string.  The
difference between a <code>&lt;gdb:lazy-string&gt;</code> and a string wrapped within
a <code>&lt;gdb:value&gt;</code> is that a <code>&lt;gdb:lazy-string&gt;</code> will be treated
differently by <span class="sc">gdb</span> when printing.  A <code>&lt;gdb:lazy-string&gt;</code> is
retrieved and encoded during printing, while a <code>&lt;gdb:value&gt;</code>
wrapping a string is immediately retrieved and encoded on creation.

   <p>The following lazy-string-related procedures are provided by the
<code>(gdb)</code> module:

<div class="defun">
&mdash; Scheme Procedure: <b>lazy-string?</b><var> object<a name="index-lazy_002dstring_003f-2806"></a></var><br>
<blockquote><p>Return <code>#t</code> if <var>object</var> is an object of type <code>&lt;gdb:lazy-string&gt;</code>. 
Otherwise return <code>#f</code>. 
</p></blockquote></div>

<div class="defun">
&mdash; Scheme Procedure: <b>lazy-string-address</b><var> lazy-sring<a name="index-lazy_002dstring_002daddress-2807"></a></var><br>
<blockquote><p>Return the address of <var>lazy-string</var>. 
</p></blockquote></div>

<div class="defun">
&mdash; Scheme Procedure: <b>lazy-string-length</b><var> lazy-string<a name="index-lazy_002dstring_002dlength-2808"></a></var><br>
<blockquote><p>Return the length of <var>lazy-string</var> in characters.  If the
length is -1, then the string will be fetched and encoded up to the
first null of appropriate width. 
</p></blockquote></div>

<div class="defun">
&mdash; Scheme Procedure: <b>lazy-string-encoding</b><var> lazy-string<a name="index-lazy_002dstring_002dencoding-2809"></a></var><br>
<blockquote><p>Return the encoding that will be applied to <var>lazy-string</var>
when the string is printed by <span class="sc">gdb</span>.  If the encoding is not
set, or contains an empty string,  then <span class="sc">gdb</span> will select the
most appropriate encoding when the string is printed. 
</p></blockquote></div>

<div class="defun">
&mdash; Scheme Procedure: <b>lazy-string-type</b><var> lazy-string<a name="index-lazy_002dstring_002dtype-2810"></a></var><br>
<blockquote><p>Return the type that is represented by <var>lazy-string</var>'s type. 
For a lazy string this is a pointer or array type.  To
resolve this to the lazy string's character type, use <code>type-target-type</code>. 
See <a href="Types-In-Guile.html#Types-In-Guile">Types In Guile</a>. 
</p></blockquote></div>

<div class="defun">
&mdash; Scheme Procedure: <b>lazy-string-&gt;value</b><var> lazy-string<a name="index-lazy_002dstring_002d_003evalue-2811"></a></var><br>
<blockquote><p>Convert the <code>&lt;gdb:lazy-string&gt;</code> to a <code>&lt;gdb:value&gt;</code>.  This value
will point to the string in memory, but will lose all the delayed
retrieval, encoding and handling that <span class="sc">gdb</span> applies to a
<code>&lt;gdb:lazy-string&gt;</code>. 
</p></blockquote></div>

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