diff options
Diffstat (limited to 'doc/manual')
| -rw-r--r-- | doc/manual/builtins.xml | 150 |
1 files changed, 96 insertions, 54 deletions
diff --git a/doc/manual/builtins.xml b/doc/manual/builtins.xml index 64d4e13ad997..9f5f4438ce55 100644 --- a/doc/manual/builtins.xml +++ b/doc/manual/builtins.xml @@ -19,7 +19,7 @@ is also available as <function>builtins.derivation</function>.</para> <variablelist> - + <varlistentry><term><function>abort</function> <replaceable>s</replaceable></term> <listitem><para>Abort Nix expression evaluation, print error @@ -27,7 +27,7 @@ is also available as <function>builtins.derivation</function>.</para> </varlistentry> - + <varlistentry><term><function>builtins.add</function> <replaceable>e1</replaceable> <replaceable>e2</replaceable></term> @@ -37,7 +37,7 @@ is also available as <function>builtins.derivation</function>.</para> </varlistentry> - + <varlistentry><term><function>builtins.attrNames</function> <replaceable>attrs</replaceable></term> @@ -55,7 +55,7 @@ attrValues = attrs: map (name: builtins.getAttr name attrs) (builtins.attrNames </varlistentry> - + <varlistentry><term><function>baseNameOf</function> <replaceable>s</replaceable></term> <listitem><para>Return the <emphasis>base name</emphasis> of the @@ -65,7 +65,7 @@ attrValues = attrs: map (name: builtins.getAttr name attrs) (builtins.attrNames </varlistentry> - + <varlistentry><term><varname>builtins</varname></term> <listitem><para>The attribute set <varname>builtins</varname> @@ -82,7 +82,7 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.compareVersions</function> <replaceable>s1</replaceable> <replaceable>s2</replaceable></term> @@ -99,7 +99,16 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting> </varlistentry> - + + <varlistentry><term><function>builtins.concatLists</function> + <replaceable>lists</replaceable></term> + + <listitem><para>Concatenate a list of lists into a single + list.</para></listitem> + + </varlistentry> + + <varlistentry xml:id='builtin-currentSystem'><term><varname>builtins.currentSystem</varname></term> @@ -124,7 +133,7 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting> </varlistentry> --> - + <!-- <varlistentry><term><function>dependencyClosure</function></term> @@ -133,7 +142,7 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting> </varlistentry> --> - + <varlistentry><term><function>derivation</function> <replaceable>attrs</replaceable></term> @@ -152,7 +161,7 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.div</function> <replaceable>e1</replaceable> <replaceable>e2</replaceable></term> @@ -162,7 +171,40 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting> </varlistentry> - + + <varlistentry><term><function>builtins.elem</function> + <replaceable>x</replaceable> <replaceable>xs</replaceable></term> + + <listitem><para>Return <literal>true</literal> if a value equal to + <replaceable>x</replaceable> occurs in the list + <replaceable>xs</replaceable>, and <literal>false</literal> + otherwise.</para></listitem> + + </varlistentry> + + + <varlistentry><term><function>builtins.elemAt</function> + <replaceable>xs</replaceable> <replaceable>n</replaceable></term> + + <listitem><para>Return element <replaceable>n</replaceable> from + the list <replaceable>xs</replaceable>. Elements are counted + starting from 0. A fatal error occurs in the index is out of + bounds.</para></listitem> + + </varlistentry> + + + <varlistentry><term><function>builtins.filter</function> + <replaceable>f</replaceable> <replaceable>xs</replaceable></term> + + <listitem><para>Return a list consisting of the elements of + <replaceable>xs</replaceable> for which the function + <replaceable>f</replaceable> returns + <literal>true</literal>.</para></listitem> + + </varlistentry> + + <varlistentry><term><function>builtins.filterSource</function> <replaceable>e1</replaceable> <replaceable>e2</replaceable></term> @@ -214,7 +256,7 @@ stdenv.mkDerivation { </varlistentry> - + <varlistentry><term><function>builtins.getAttr</function> <replaceable>s</replaceable> <replaceable>attrs</replaceable></term> @@ -227,7 +269,7 @@ stdenv.mkDerivation { </varlistentry> - + <varlistentry><term><function>builtins.getEnv</function> <replaceable>s</replaceable></term> @@ -245,7 +287,7 @@ stdenv.mkDerivation { </varlistentry> - + <varlistentry><term><function>builtins.hasAttr</function> <replaceable>s</replaceable> <replaceable>attrs</replaceable></term> @@ -259,7 +301,7 @@ stdenv.mkDerivation { </varlistentry> - + <varlistentry><term><function>builtins.head</function> <replaceable>list</replaceable></term> @@ -270,7 +312,7 @@ stdenv.mkDerivation { </varlistentry> - + <varlistentry><term><function>import</function> <replaceable>path</replaceable></term> @@ -290,7 +332,7 @@ stdenv.mkDerivation { built-in). Therefore, it cannot refer to variables that are in scope at the call site. For instance, if you have a calling expression - + <programlisting> rec { x = 123; @@ -325,7 +367,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.intersectAttrs</function> <replaceable>e1</replaceable> <replaceable>e2</replaceable></term> @@ -334,8 +376,8 @@ x: x + 456</programlisting> exist in the set <replaceable>e1</replaceable>.</para></listitem> </varlistentry> - - + + <varlistentry><term><function>builtins.isAttrs</function> <replaceable>e</replaceable></term> @@ -345,7 +387,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.isList</function> <replaceable>e</replaceable></term> @@ -355,7 +397,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.isFunction</function> <replaceable>e</replaceable></term> @@ -365,7 +407,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.isString</function> <replaceable>e</replaceable></term> @@ -375,7 +417,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.isInt</function> <replaceable>e</replaceable></term> @@ -385,7 +427,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.isBool</function> <replaceable>e</replaceable></term> @@ -395,7 +437,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>isNull</function> <replaceable>e</replaceable></term> @@ -405,12 +447,12 @@ x: x + 456</programlisting> <warning><para>This function is <emphasis>deprecated</emphasis>; just write <literal>e == null</literal> instead.</para></warning> - + </listitem> </varlistentry> - + <varlistentry><term><function>builtins.length</function> <replaceable>e</replaceable></term> @@ -419,7 +461,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.lessThan</function> <replaceable>e1</replaceable> <replaceable>e2</replaceable></term> @@ -432,7 +474,7 @@ x: x + 456</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.listToAttrs</function> <replaceable>e</replaceable></term> @@ -459,7 +501,7 @@ builtins.listToAttrs </para></listitem> </varlistentry> - + <varlistentry><term><function>map</function> <replaceable>f</replaceable> <replaceable>list</replaceable></term> @@ -472,10 +514,10 @@ map (x: "foo" + x) [ "bar" "bla" "abc" ]</programlisting> evaluates to <literal>[ "foobar" "foobla" "fooabc" ]</literal>.</para></listitem> - + </varlistentry> - + <varlistentry><term><function>builtins.mul</function> <replaceable>e1</replaceable> <replaceable>e2</replaceable></term> @@ -485,7 +527,7 @@ map (x: "foo" + x) [ "bar" "bla" "abc" ]</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.parseDrvName</function> <replaceable>s</replaceable></term> @@ -500,7 +542,7 @@ map (x: "foo" + x) [ "bar" "bla" "abc" ]</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.pathExists</function> <replaceable>path</replaceable></term> @@ -533,7 +575,7 @@ in config.someSetting</programlisting> </varlistentry> --> - + <varlistentry><term><function>builtins.readFile</function> <replaceable>path</replaceable></term> @@ -541,8 +583,8 @@ in config.someSetting</programlisting> <replaceable>path</replaceable> as a string.</para></listitem> </varlistentry> - - + + <varlistentry><term><function>removeAttrs</function> <replaceable>attrs</replaceable> <replaceable>list</replaceable></term> @@ -558,7 +600,7 @@ removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]</screen> </varlistentry> - + <varlistentry><term><function>builtins.stringLength</function> <replaceable>e</replaceable></term> @@ -568,7 +610,7 @@ removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]</screen> </varlistentry> - + <varlistentry><term><function>builtins.sub</function> <replaceable>e1</replaceable> <replaceable>e2</replaceable></term> @@ -578,7 +620,7 @@ removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]</screen> </varlistentry> - + <varlistentry><term><function>builtins.substring</function> <replaceable>start</replaceable> <replaceable>len</replaceable> <replaceable>s</replaceable></term> @@ -596,7 +638,7 @@ removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]</screen> </varlistentry> - + <varlistentry><term><function>builtins.tail</function> <replaceable>list</replaceable></term> @@ -606,7 +648,7 @@ removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]</screen> </varlistentry> - + <varlistentry><term><function>throw</function> <replaceable>s</replaceable></term> @@ -620,7 +662,7 @@ removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]</screen> </varlistentry> - + <varlistentry xml:id='builtin-toFile'><term><function>builtins.toFile</function> <replaceable>name</replaceable> <replaceable>s</replaceable></term> @@ -638,7 +680,7 @@ removeAttrs { x = 1; y = 2; z = 3; } [ "a" "x" "z" ]</screen> stdenv.mkDerivation { name = "hello-2.1.1"; - + builder = builtins.toFile "builder.sh" " source $stdenv/setup @@ -657,7 +699,7 @@ stdenv.mkDerivation { }; inherit perl; }</programlisting> - + </para> <para>It is even possible for one file to refer to another, e.g., @@ -695,7 +737,7 @@ in foo</programlisting> </varlistentry> - + <varlistentry><term><function>builtins.toPath</function> <replaceable>s</replaceable></term> <listitem><para>Convert the string value @@ -708,7 +750,7 @@ in foo</programlisting> </varlistentry> - + <varlistentry><term><function>toString</function> <replaceable>e</replaceable></term> <listitem><para>Convert the expression @@ -720,7 +762,7 @@ in foo</programlisting> </varlistentry> - + <varlistentry xml:id='builtin-toXML'><term><function>builtins.toXML</function> <replaceable>e</replaceable></term> <listitem><para>Return a string containing an XML representation @@ -765,7 +807,7 @@ in foo</programlisting> <example xml:id='ex-toxml'><title>Passing information to a builder using <function>toXML</function></title> - + <programlisting><![CDATA[ { stdenv, fetchurl, libxslt, jira, uberwiki }: @@ -773,7 +815,7 @@ stdenv.mkDerivation (rec { name = "web-server"; buildInputs = [ libxslt ]; - + builder = builtins.toFile "builder.sh" " source $stdenv/setup mkdir $out @@ -806,7 +848,7 @@ stdenv.mkDerivation (rec { <example xml:id='ex-toxml-result'><title>XML representation produced by <function>toXML</function></title> - + <programlisting><![CDATA[<?xml version='1.0' encoding='utf-8'?> <expr> <list> @@ -835,7 +877,7 @@ stdenv.mkDerivation (rec { </varlistentry> - + <varlistentry><term><function>builtins.trace</function> <replaceable>e1</replaceable> <replaceable>e2</replaceable></term> @@ -846,7 +888,7 @@ stdenv.mkDerivation (rec { </varlistentry> - + </variablelist> |