diff options
Diffstat (limited to 'doc/manual/expressions/builtins.xml')
| -rw-r--r-- | doc/manual/expressions/builtins.xml | 29 |
1 files changed, 6 insertions, 23 deletions
diff --git a/doc/manual/expressions/builtins.xml b/doc/manual/expressions/builtins.xml index 873f30b062ee..3f396ac1d991 100644 --- a/doc/manual/expressions/builtins.xml +++ b/doc/manual/expressions/builtins.xml @@ -1027,22 +1027,8 @@ Evaluates to <literal>[ "foo" ]</literal>. <replaceable>path</replaceable></term> <listitem><para>Return <literal>true</literal> if the path - <replaceable>path</replaceable> exists, and - <literal>false</literal> otherwise. One application of this - function is to conditionally include a Nix expression containing - user configuration: - -<programlisting> -let - fileName = builtins.getEnv "CONFIG_FILE"; - config = - if fileName != "" && builtins.pathExists (builtins.toPath fileName) - then import (builtins.toPath fileName) - else { someSetting = false; }; <lineannotation># default configuration</lineannotation> -in config.someSetting</programlisting> - - (Note that <envar>CONFIG_FILE</envar> must be an absolute path for - this to work.)</para></listitem> + <replaceable>path</replaceable> exists at evaluation time, and + <literal>false</literal> otherwise. </varlistentry> @@ -1344,13 +1330,10 @@ in foo</programlisting> <varlistentry><term><function>builtins.toPath</function> <replaceable>s</replaceable></term> - <listitem><para>Convert the string value - <replaceable>s</replaceable> into a path value. The string - <replaceable>s</replaceable> must represent an absolute path - (i.e., must start with <literal>/</literal>). The path need not - exist. The resulting path is canonicalised, e.g., - <literal>builtins.toPath "//foo/xyzzy/../bar/"</literal> returns - <literal>/foo/bar</literal>.</para></listitem> + <listitem><para> DEPRECATED. Use <literal>/. + "/path"</literal> + to convert a string into an absolute path. For relative paths, + use <literal>./. + "/path"</literal>. + </para></listitem> </varlistentry> |