Commit 61311665 authored by Profpatsch's avatar Profpatsch
Browse files

lib: add ini configuration generator 

Many configurations are INI-style files. Attribute sets can be mapped
rather painlessly to the INI format.
This adds a function toINI inside a new generators library section.
Also, unit tests for the default values are provided.
parent ba73dbbd

lib/default.nix

+2 −1
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ let 


  # misc

  debug = import ./debug.nix;

  generators = import ./generators.nix;

  misc = import ./deprecated.nix;



  # domain-specific
@@ -39,7 +40,7 @@ in 
            customisation maintainers meta sources

            modules options types

            licenses platforms systems

            debug misc

            debug generators misc

            sandbox fetchers;

  }

  # !!! don't include everything at top-level; perhaps only the most

lib/generators.nix

0 → 100644
+53 −0
Original line number Diff line number Diff line 
/* Functions that generate widespread config file

 * formats from nix data structures.

 * Tests can be found in ./tests.nix

 */

with import ./trivial.nix;

let

  libStr = import ./strings.nix;

  libAttr = import ./attrsets.nix;



  flipMapAttrs = flip libAttr.mapAttrs;

in



{



  /* Generates an INI-style config file from an

   * attrset of sections to an attrset of key-value pairs.

   *

   * generators.toINI {} {

   *   foo = { hi = "${pkgs.hello}"; ciao = "bar"; };

   *   baz = { "also, integers" = 42; };

   * }

   *

   *> [baz]

   *> also, integers=42

   *>

   *> [foo]

   *> ciao=bar

   *> hi=/nix/store/y93qql1p5ggfnaqjjqhxcw0vqw95rlz0-hello-2.10

   *

   * The mk* configuration attributes can generically change

   * the way sections and key-value strings are generated.

   *

   * For more examples see the test cases in ./tests.nix.

   */

  toINI = {

    # apply transformations (e.g. escapes) to section names

    mkSectionName ? (name: libStr.escape [ "[" "]" ] name),

    # format a setting line from key and value

    mkKeyValue    ? (k: v: "${libStr.escape ["="] k}=${toString v}")

  }: attrsOfAttrs:

    let

        # map function to string for each key val

        mapAttrsToStringsSep = sep: mapFn: attrs:

          libStr.concatStringsSep sep

            (libAttr.mapAttrsToList mapFn attrs);

        mkLine = k: v: mkKeyValue k v + "\n";

        mkSection = sectName: sectValues: ''

          [${mkSectionName sectName}]

        '' + libStr.concatStrings (libAttr.mapAttrsToList mkLine sectValues);

    in

      # map input to ini sections

      mapAttrsToStringsSep "\n" mkSection attrsOfAttrs;

}

lib/tests.nix

+51 −0
Original line number Diff line number Diff line
@@ -130,4 +130,55 @@ runTests { 
    expected = false;

  };





  /* Generator tests */

  # these tests assume attributes are converted to lists

  # in alphabetical order



  testToINIEmpty = {

    expr = generators.toINI {} {};

    expected = "";

  };



  testToINIEmptySection = {

    expr = generators.toINI {} { foo = {}; bar = {}; };

    expected = ''

      [bar]



      [foo]

    '';

  };



  testToINIDefaultEscapes = {

    expr = generators.toINI {} {

      "no [ and ] allowed unescaped" = {

        "and also no = in keys" = 42;

      };

    };

    expected = ''

      [no \[ and \] allowed unescaped]

      and also no \= in keys=42

    '';

  };



  testToINIDefaultFull = {

    expr = generators.toINI {} {

      "section 1" = {

        attribute1 = 5;

        x = "Me-se JarJar Binx";

      };

      "foo[]" = {

        "he\\h=he" = "this is okay";

      };

    };

    expected = ''

      [foo\[\]]

      he\h\=he=this is okay



      [section 1]

      attribute1=5

      x=Me-se JarJar Binx

    '';

  };



}