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Define single complete types in the overview of the type system

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Reviewed-by: Will Thompson <will.thompson@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=38252
This commit is contained in:
Simon McVittie 2011-05-25 17:59:07 +01:00
parent 8624dbec2d
commit 7461c704b9
1 changed files with 39 additions and 30 deletions
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69
doc/dbus-specification.xml
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@ -295,13 +295,50 @@
<para>
The D-Bus protocol does not include type tags in the marshaled data; a
block of marshaled values must have a known <firstterm>type
signature</firstterm>. The type signature is made up of <firstterm>type
codes</firstterm>. A type code is an ASCII character representing the
signature</firstterm>. The type signature is made up of zero or more
<firstterm id="term-single-complete-type">single complete
types</firstterm>, each made up of one or more
<firstterm>type codes</firstterm>.
</para>
<para>
A type code is an ASCII character representing the
type of a value. Because ASCII characters are used, the type signature
will always form a valid ASCII string. A simple string compare
determines whether two type signatures are equivalent.
</para>
<para>
A single complete type is a sequence of type codes that fully describes
one type: either a basic type, or a single fully-described container type.
A single complete type is a basic type code, a variant type code,
an array with its element type, or a struct with its fields (all of which
are defined below). So the following signatures are not single complete
types:
<programlisting>
"aa"
</programlisting>
<programlisting>
"(ii"
</programlisting>
<programlisting>
"ii)"
</programlisting>
And the following signatures contain multiple complete types:
<programlisting>
"ii"
</programlisting>
<programlisting>
"aiai"
</programlisting>
<programlisting>
"(ii)(ii)"
</programlisting>
Note however that a single complete type may <emphasis>contain</emphasis>
multiple other single complete types, by containing a struct or dict
entry.
</para>
<sect2 id="basic-types">
<title>Basic types</title>
@ -384,34 +421,6 @@
</programlisting>
</para>
<para>
The phrase <firstterm>single complete type</firstterm> deserves some
definition. A single complete type is a basic type code, a variant type code,
an array with its element type, or a struct with its fields.
So the following signatures are not single complete types:
<programlisting>
"aa"
</programlisting>
<programlisting>
"(ii"
</programlisting>
<programlisting>
"ii)"
</programlisting>
And the following signatures contain multiple complete types:
<programlisting>
"ii"
</programlisting>
<programlisting>
"aiai"
</programlisting>
<programlisting>
"(ii)(ii)"
</programlisting>
Note however that a single complete type may <emphasis>contain</emphasis>
multiple other single complete types.
</para>
<para>
<literal>VARIANT</literal> has ASCII character 'v' as its type code. A marshaled value of
type <literal>VARIANT</literal> will have the signature of a single complete type as part