145 lines
6.8 KiB
HTML
145 lines
6.8 KiB
HTML
|
|
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
|
|
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
|
|
<title>Differences between D:YAML and the YAML specification — D:YAML v0.3 documentation</title>
|
|
<link rel="stylesheet" href="../_static/default.css" type="text/css" />
|
|
<link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
|
|
<script type="text/javascript">
|
|
var DOCUMENTATION_OPTIONS = {
|
|
URL_ROOT: '../',
|
|
VERSION: '0.3',
|
|
COLLAPSE_INDEX: false,
|
|
FILE_SUFFIX: '.html',
|
|
HAS_SOURCE: true
|
|
};
|
|
</script>
|
|
<script type="text/javascript" src="../_static/jquery.js"></script>
|
|
<script type="text/javascript" src="../_static/underscore.js"></script>
|
|
<script type="text/javascript" src="../_static/doctools.js"></script>
|
|
<link rel="top" title="D:YAML v0.3 documentation" href="../index.html" />
|
|
<link rel="prev" title="YAML syntax" href="../tutorials/yaml_syntax.html" />
|
|
</head>
|
|
<body>
|
|
<div class="related">
|
|
<h3>Navigation</h3>
|
|
<ul>
|
|
<li class="right" style="margin-right: 10px">
|
|
<a href="../tutorials/yaml_syntax.html" title="YAML syntax"
|
|
accesskey="P">previous</a></li>
|
|
<li><a href="../index.html">D:YAML v0.3 documentation</a> »</li>
|
|
</ul>
|
|
</div>
|
|
|
|
<div class="document">
|
|
<div class="documentwrapper">
|
|
<div class="bodywrapper">
|
|
<div class="body">
|
|
|
|
<div class="section" id="differences-between-d-yaml-and-the-yaml-specification">
|
|
<h1>Differences between D:YAML and the YAML specification<a class="headerlink" href="#differences-between-d-yaml-and-the-yaml-specification" title="Permalink to this headline">¶</a></h1>
|
|
<p>There are some differences between D:YAML and the YAML 1.1 specification. Some
|
|
are caused by difficulty of implementation of some features, such as multiple
|
|
Unicode encodings within single stream, and some by unnecessary restrictions or
|
|
ambiguities in the specification.</p>
|
|
<p>Still, D:YAML tries to be as close to the specification as possible. It should
|
|
never load documents with different meaning than according to the specification,
|
|
and documents that fail to load should be very rare (for instance, very few
|
|
files use multiple Unicode encodings).</p>
|
|
<div class="section" id="list-of-known-differences">
|
|
<h2>List of known differences:<a class="headerlink" href="#list-of-known-differences" title="Permalink to this headline">¶</a></h2>
|
|
<p>Differences that can cause valid YAML documents not to load:</p>
|
|
<ul>
|
|
<li><p class="first">No support for byte order marks and multiple Unicode encodings in a stream.</p>
|
|
</li>
|
|
<li><p class="first">Plain scalars in flow context cannot contain <tt class="docutils literal"><span class="pre">,</span></tt>, <tt class="docutils literal"><span class="pre">:</span></tt> and <tt class="docutils literal"><span class="pre">?</span></tt>.
|
|
This might change with <tt class="docutils literal"><span class="pre">:</span></tt> in the future.
|
|
See <a class="reference external" href="http://pyyaml.org/wiki/YAMLColonInFlowContext">http://pyyaml.org/wiki/YAMLColonInFlowContext</a> for details.</p>
|
|
</li>
|
|
<li><p class="first">The specification does not restrict characters for anchors and
|
|
aliases. This may lead to problems, for instance, the document:</p>
|
|
<div class="highlight-yaml"><div class="highlight"><pre><span class="p-Indicator">[</span> <span class="nv">*alias</span><span class="p-Indicator">,</span> <span class="nv">value</span> <span class="p-Indicator">]</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>can be interpteted in two ways, as:</p>
|
|
<div class="highlight-yaml"><div class="highlight"><pre><span class="p-Indicator">[</span> <span class="s">"value"</span> <span class="p-Indicator">]</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>and:</p>
|
|
<div class="highlight-yaml"><div class="highlight"><pre><span class="p-Indicator">[</span> <span class="nv">*alias</span> <span class="p-Indicator">,</span> <span class="s">"value"</span> <span class="p-Indicator">]</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>Therefore we restrict aliases and anchors to ASCII alphanumeric characters.</p>
|
|
</li>
|
|
<li><p class="first">The specification is confusing about tabs in plain scalars. We don’t use tabs
|
|
in plain scalars at all.</p>
|
|
</li>
|
|
<li><p class="first">There is no support for recursive data structures in DYAML.</p>
|
|
</li>
|
|
</ul>
|
|
<p>Other differences:</p>
|
|
<ul>
|
|
<li><p class="first">Indentation is ignored in the flow context, which is less restrictive than the
|
|
specification. This allows code such as:</p>
|
|
<div class="highlight-yaml"><div class="highlight"><pre><span class="l-Scalar-Plain">key</span><span class="p-Indicator">:</span> <span class="p-Indicator">{</span>
|
|
<span class="p-Indicator">}</span>
|
|
</pre></div>
|
|
</div>
|
|
</li>
|
|
<li><p class="first">Indentation rules for quoted scalars are loosed: They don’t need to adhere
|
|
indentation as <tt class="docutils literal"><span class="pre">"</span></tt> and <tt class="docutils literal"><span class="pre">'</span></tt> clearly mark the beginning and the end of them.</p>
|
|
</li>
|
|
<li><p class="first">We allow <tt class="docutils literal"><span class="pre">_</span></tt> in tag handles.</p>
|
|
</li>
|
|
<li><p class="first">Right now, two mappings with the same contents but different orderings are
|
|
considered unequal, even if they are unordered mappings. This is because all
|
|
mappings are ordered in the D:YAML implementation. This should change in
|
|
future, once D associative arrays work with variant types or a map class or
|
|
struct appears in Phobos.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sphinxsidebar">
|
|
<div class="sphinxsidebarwrapper">
|
|
<p class="logo"><a href="../index.html">
|
|
<img class="logo" src="../_static/logo210.png" alt="Logo"/>
|
|
</a></p>
|
|
<h3><a href="../index.html">Table Of Contents</a></h3>
|
|
<ul>
|
|
<li><a class="reference internal" href="#">Differences between D:YAML and the YAML specification</a><ul>
|
|
<li><a class="reference internal" href="#list-of-known-differences">List of known differences:</a></li>
|
|
</ul>
|
|
</li>
|
|
</ul>
|
|
|
|
</div>
|
|
</div>
|
|
<div class="clearer"></div>
|
|
</div>
|
|
<div class="related">
|
|
<h3>Navigation</h3>
|
|
<ul>
|
|
<li class="right" style="margin-right: 10px">
|
|
<a href="../tutorials/yaml_syntax.html" title="YAML syntax"
|
|
>previous</a></li>
|
|
<li><a href="../index.html">D:YAML v0.3 documentation</a> »</li>
|
|
</ul>
|
|
</div>
|
|
<div class="footer">
|
|
© Copyright 2011, Ferdinand Majerech. Based on PyYAML http://www.pyyaml.org by Kirill Simonov.
|
|
Last updated on Nov 18, 2011.
|
|
Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.0.7.
|
|
</div>
|
|
</body>
|
|
</html> |