You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
143 lines
7.0 KiB
HTML
143 lines
7.0 KiB
HTML
4 years ago
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- Copyright (C) 1988-2019 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
Permission is granted to copy, distribute and/or modify this document
|
||
|
|
under the terms of the GNU Free Documentation License, Version 1.3 or
|
||
|
|
any later version published by the Free Software Foundation; with the
|
||
|
|
Invariant Sections being "Free Software" and "Free Software Needs
|
||
|
|
Free Documentation", with the Front-Cover Texts being "A GNU Manual,"
|
||
|
|
and with the Back-Cover Texts as in (a) below.
|
||
|
|
|
||
|
|
(a) The FSF's Back-Cover Text is: "You are free to copy and modify
|
||
|
|
this GNU Manual. Buying copies from GNU Press supports the FSF in
|
||
|
|
developing GNU and promoting software freedom." -->
|
||
|
|
<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>Lazy Strings In Guile (Debugging with GDB)</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Lazy Strings In Guile (Debugging with GDB)">
|
||
|
|
<meta name="keywords" content="Lazy Strings In Guile (Debugging with GDB)">
|
||
|
|
<meta name="resource-type" content="document">
|
||
|
|
<meta name="distribution" content="global">
|
||
|
|
<meta name="Generator" content="makeinfo">
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<link href="index.html#Top" rel="start" title="Top">
|
||
|
|
<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="Guile-API.html#Guile-API" rel="up" title="Guile API">
|
||
|
|
<link href="Architectures-In-Guile.html#Architectures-In-Guile" rel="next" title="Architectures In Guile">
|
||
|
|
<link href="Breakpoints-In-Guile.html#Breakpoints-In-Guile" rel="prev" title="Breakpoints In Guile">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.indentedblock {margin-right: 0em}
|
||
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
div.smalllisp {margin-left: 3.2em}
|
||
|
|
kbd {font-style: oblique}
|
||
|
|
pre.display {font-family: inherit}
|
||
|
|
pre.format {font-family: inherit}
|
||
|
|
pre.menu-comment {font-family: serif}
|
||
|
|
pre.menu-preformatted {font-family: serif}
|
||
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smallexample {font-size: smaller}
|
||
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smalllisp {font-size: smaller}
|
||
|
|
span.nolinebreak {white-space: nowrap}
|
||
|
|
span.roman {font-family: initial; font-weight: normal}
|
||
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en">
|
||
|
|
<a name="Lazy-Strings-In-Guile"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Architectures-In-Guile.html#Architectures-In-Guile" accesskey="n" rel="next">Architectures In Guile</a>, Previous: <a href="Breakpoints-In-Guile.html#Breakpoints-In-Guile" accesskey="p" rel="prev">Breakpoints In Guile</a>, Up: <a href="Guile-API.html#Guile-API" accesskey="u" rel="up">Guile API</a> [<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>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="Guile-representation-of-lazy-strings_002e"></a>
|
||
|
|
<h4 class="subsubsection">23.3.3.20 Guile representation of lazy strings.</h4>
|
||
|
|
|
||
|
|
<a name="index-lazy-strings-in-guile"></a>
|
||
|
|
<a name="index-_003cgdb_003alazy_002dstring_003e"></a>
|
||
|
|
|
||
|
|
<p>A <em>lazy string</em> is a string whose contents is not retrieved or
|
||
|
|
encoded until it is needed.
|
||
|
|
</p>
|
||
|
|
<p>A <code><gdb:lazy-string></code> is represented in <small>GDB</small> 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><gdb:lazy-string></code> and a string wrapped within
|
||
|
|
a <code><gdb:value></code> is that a <code><gdb:lazy-string></code> will be treated
|
||
|
|
differently by <small>GDB</small> when printing. A <code><gdb:lazy-string></code> is
|
||
|
|
retrieved and encoded during printing, while a <code><gdb:value></code>
|
||
|
|
wrapping a string is immediately retrieved and encoded on creation.
|
||
|
|
</p>
|
||
|
|
<p>The following lazy-string-related procedures are provided by the
|
||
|
|
<code>(gdb)</code> module:
|
||
|
|
</p>
|
||
|
|
<dl>
|
||
|
|
<dt><a name="index-lazy_002dstring_003f"></a>Scheme Procedure: <strong>lazy-string?</strong> <em>object</em></dt>
|
||
|
|
<dd><p>Return <code>#t</code> if <var>object</var> is an object of type <code><gdb:lazy-string></code>.
|
||
|
|
Otherwise return <code>#f</code>.
|
||
|
|
</p></dd></dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt><a name="index-lazy_002dstring_002daddress"></a>Scheme Procedure: <strong>lazy-string-address</strong> <em>lazy-sring</em></dt>
|
||
|
|
<dd><p>Return the address of <var>lazy-string</var>.
|
||
|
|
</p></dd></dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt><a name="index-lazy_002dstring_002dlength"></a>Scheme Procedure: <strong>lazy-string-length</strong> <em>lazy-string</em></dt>
|
||
|
|
<dd><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></dd></dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt><a name="index-lazy_002dstring_002dencoding"></a>Scheme Procedure: <strong>lazy-string-encoding</strong> <em>lazy-string</em></dt>
|
||
|
|
<dd><p>Return the encoding that will be applied to <var>lazy-string</var>
|
||
|
|
when the string is printed by <small>GDB</small>. If the encoding is not
|
||
|
|
set, or contains an empty string, then <small>GDB</small> will select the
|
||
|
|
most appropriate encoding when the string is printed.
|
||
|
|
</p></dd></dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt><a name="index-lazy_002dstring_002dtype"></a>Scheme Procedure: <strong>lazy-string-type</strong> <em>lazy-string</em></dt>
|
||
|
|
<dd><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></dd></dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt><a name="index-lazy_002dstring_002d_003evalue"></a>Scheme Procedure: <strong>lazy-string->value</strong> <em>lazy-string</em></dt>
|
||
|
|
<dd><p>Convert the <code><gdb:lazy-string></code> to a <code><gdb:value></code>. This value
|
||
|
|
will point to the string in memory, but will lose all the delayed
|
||
|
|
retrieval, encoding and handling that <small>GDB</small> applies to a
|
||
|
|
<code><gdb:lazy-string></code>.
|
||
|
|
</p></dd></dl>
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Architectures-In-Guile.html#Architectures-In-Guile" accesskey="n" rel="next">Architectures In Guile</a>, Previous: <a href="Breakpoints-In-Guile.html#Breakpoints-In-Guile" accesskey="p" rel="prev">Breakpoints In Guile</a>, Up: <a href="Guile-API.html#Guile-API" accesskey="u" rel="up">Guile API</a> [<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>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|