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nixos docs: format =)

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Graham Christensen
2018-05-01 19:57:09 -04:00
parent 77161de454
commit eca5c99bf8
91 changed files with 9705 additions and 7852 deletions
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nixos/doc/manual/development/assertions.xml
+29 -35
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@@ -3,30 +3,29 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-assertions">
<title>Warnings and Assertions</title>
<title>Warnings and Assertions</title>
<para>
When configuration problems are detectable in a module, it is a good idea to
write an assertion or warning. Doing so provides clear feedback to the user
and prevents errors after the build.
</para>
<para>
When configuration problems are detectable in a module, it is a good
idea to write an assertion or warning. Doing so provides clear
feedback to the user and prevents errors after the build.
</para>
<para>
<para>
Although Nix has the <literal>abort</literal> and
<literal>builtins.trace</literal> <link xlink:href="https://nixos.org/nix/manual/#ssec-builtins">functions</link> to perform such tasks,
they are not ideally suited for NixOS modules. Instead of these
functions, you can declare your warnings and assertions using the
<literal>builtins.trace</literal>
<link xlink:href="https://nixos.org/nix/manual/#ssec-builtins">functions</link>
to perform such tasks, they are not ideally suited for NixOS modules. Instead
of these functions, you can declare your warnings and assertions using the
NixOS module system.
</para>
</para>
<section>
<section>
<title>Warnings</title>
<title>Warnings</title>
<para>
This is an example of using <literal>warnings</literal>.
</para>
<para>
This is an example of using <literal>warnings</literal>.
</para>
<programlisting>
<![CDATA[
@@ -43,22 +42,19 @@
}
]]>
</programlisting>
</section>
</section>
<section>
<title>Assertions</title>
<section>
<title>Assertions</title>
<para>
This example, extracted from the
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/release-17.09/nixos/modules/services/logging/syslogd.nix">
<literal>syslogd</literal> module
</link> shows how to use <literal>assertions</literal>. Since there
can only be one active syslog daemon at a time, an assertion is useful to
prevent such a broken system from being built.
</para>
<para>
This example, extracted from the
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/release-17.09/nixos/modules/services/logging/syslogd.nix">
<literal>syslogd</literal> module </link> shows how to use
<literal>assertions</literal>. Since there can only be one active syslog
daemon at a time, an assertion is useful to prevent such a broken system
from being built.
</para>
<programlisting>
<![CDATA[
@@ -74,7 +70,5 @@
}
]]>
</programlisting>
</section>
</section>
</section>