From 6d6c68c0d29310b6eca35f58b1e68f495d6cd33a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <e.dolstra@tudelft.nl>
Date: Fri, 30 Nov 2007 16:48:45 +0000
Subject: * Added a new kind of multi-line string literal delimited by two  
 single quotes.  Example (from NixOS):

    job = ''
      start on network-interfaces

      start script

        rm -f /var/run/opengl-driver
        ${if videoDriver == "nvidia"
          then "ln -sf ${nvidiaDrivers} /var/run/opengl-driver"
          else if cfg.driSupport
          then "ln -sf ${mesa} /var/run/opengl-driver"
          else ""
        }

        rm -f /var/log/slim.log

      end script
    '';

  This style has two big advantages:

  - \, ' and " aren't special, only '' and ${.  So you get a lot less
    escaping in shell scripts / configuration files in Nixpkgs/NixOS.
    The delimiter '' is rare in scripts (and can usually be written as
    "").  ${ is also fairly rare.

    Other delimiters such as <<...>>, {{...}} and <|...|> were also
    considered but this one appears to have the fewest drawbacks
    (thanks Martin).

  - Indentation is intelligently stripped so that multi-line strings
    can follow the nesting structure of the containing Nix
    expression.  E.g. in the example above 6 spaces are stripped from
    the start of each line.  This prevents unnecessary indentation in
    generated files (which sometimes even breaks things).

  See tests/lang/eval-okay-ind-string.nix for some examples.
---
 doc/manual/release-notes.xml | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'doc')

diff --git a/doc/manual/release-notes.xml b/doc/manual/release-notes.xml
index 727a3e4a6..ef2905d8a 100644
--- a/doc/manual/release-notes.xml
+++ b/doc/manual/release-notes.xml
@@ -131,6 +131,10 @@
   <listitem><para>TODO: chroot support.</para></listitem>
   
 
+  <listitem><para>TODO: <literal>''</literal>-style string
+  literals.</para></listitem>
+  
+
 </itemizedlist>
 
 </section>
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