nixpkgs manual: split languages into separate files

There's no change in content except for amending the title of the
section to mention "frameworks", as e.g. I don't consider Qt a language,
and it's likely there will be more of similar cases in future.

To be certain, I checked diff of the generated HTMLs.

1 files changed, 124 insertions, 0 deletions

diff --git a/doc/languages-frameworks/go.xml b/doc/languages-frameworks/go.xml
new file mode 100644
index 00000000000..89908b3b8ff
--- /dev/null
+++ b/doc/languages-frameworks/go.xml
@@ -0,0 +1,124 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-go">
+
+<title>Go</title>
+
+<para>The function <varname>buildGoPackage</varname> builds
+standard Go packages.
+</para>
+
+<example xml:id='ex-buildGoPackage'><title>buildGoPackage</title>
+<programlisting>
+net = buildGoPackage rec {
+  name = "go.net-${rev}";
+  goPackagePath = "golang.org/x/net"; <co xml:id='ex-buildGoPackage-1' />
+  subPackages = [ "ipv4" "ipv6" ]; <co xml:id='ex-buildGoPackage-2' />
+  rev = "e0403b4e005";
+  src = fetchFromGitHub {
+    inherit rev;
+    owner = "golang";
+    repo = "net";
+    sha256 = "1g7cjzw4g4301a3yqpbk8n1d4s97sfby2aysl275x04g0zh8jxqp";
+  };
+  goPackageAliases = [ "code.google.com/p/go.net" ]; <co xml:id='ex-buildGoPackage-3' />
+  propagatedBuildInputs = [ goPackages.text ]; <co xml:id='ex-buildGoPackage-4' />
+  buildFlags = "--tags release"; <co xml:id='ex-buildGoPackage-5' />
+  disabled = isGo13;<co xml:id='ex-buildGoPackage-6' />
+};
+</programlisting>
+</example>
+
+<para><xref linkend='ex-buildGoPackage'/> is an example expression using buildGoPackage,
+the following arguments are of special significance to the function:
+
+<calloutlist>
+
+  <callout arearefs='ex-buildGoPackage-1'>
+    <para>
+      <varname>goPackagePath</varname> specifies the package's canonical Go import path.
+    </para>
+  </callout>
+
+  <callout arearefs='ex-buildGoPackage-2'>
+    <para>
+      <varname>subPackages</varname> limits the builder from building child packages that
+      have not been listed. If <varname>subPackages</varname> is not specified, all child
+      packages will be built.
+    </para>
+    <para>
+      In this example only <literal>code.google.com/p/go.net/ipv4</literal> and
+      <literal>code.google.com/p/go.net/ipv6</literal> will be built.
+    </para>
+  </callout>
+
+  <callout arearefs='ex-buildGoPackage-3'>
+    <para>
+      <varname>goPackageAliases</varname> is a list of alternative import paths
+      that are valid for this library.
+      Packages that depend on this library will automatically rename
+      import paths that match any of the aliases to <literal>goPackagePath</literal>.
+    </para>
+    <para>
+      In this example imports will be renamed from
+      <literal>code.google.com/p/go.net</literal> to
+      <literal>golang.org/x/net</literal> in every package that depend on the
+      <literal>go.net</literal> library.
+    </para>
+  </callout>
+
+  <callout arearefs='ex-buildGoPackage-4'>
+    <para>
+      <varname>propagatedBuildInputs</varname> is where the dependencies of a Go library are
+      listed. Only libraries should list <varname>propagatedBuildInputs</varname>. If a standalone
+      program is being built instead, use <varname>buildInputs</varname>. If a library's tests require
+      additional dependencies that are not propagated, they should be listed in <varname>buildInputs</varname>.
+    </para>
+  </callout>
+
+  <callout arearefs='ex-buildGoPackage-5'>
+    <para>
+      <varname>buildFlags</varname> is a list of flags passed to the go build command.
+    </para>
+  </callout>
+
+  <callout arearefs='ex-buildGoPackage-6'>
+    <para>
+      If <varname>disabled</varname> is <literal>true</literal>,
+      nix will refuse to build this package.
+    </para>
+    <para>
+      In this example the package will not be built for go 1.3. The <literal>isGo13</literal>
+      is an utility function that returns <literal>true</literal> if go used to build the
+      package has version 1.3.x.
+    </para>
+  </callout>
+
+</calloutlist>
+
+</para>
+
+<para>
+Reusable Go libraries may be found in the <varname>goPackages</varname> set. You can test
+build a Go package as follows:
+
+<screen>
+$ nix-build -A goPackages.net
+</screen>
+
+</para>
+
+<para>
+You may use Go packages installed into the active Nix profiles by adding
+the following to your ~/.bashrc:
+
+<screen>
+for p in $NIX_PROFILES; do
+    GOPATH="$p/share/go:$GOPATH"
+done
+</screen>
+</para>
+
+  <para>To extract dependency information from a Go package in automated way use <link xlink:href="https://github.com/cstrahan/go2nix">go2nix</link>.</para>
+</section>
+