226 lines
7.2 KiB
Nix
226 lines
7.2 KiB
Nix
/* Functions that generate widespread file
|
|
* formats from nix data structures.
|
|
*
|
|
* They all follow a similar interface:
|
|
* generator { config-attrs } data
|
|
*
|
|
* `config-attrs` are “holes” in the generators
|
|
* with sensible default implementations that
|
|
* can be overwritten. The default implementations
|
|
* are mostly generators themselves, called with
|
|
* their respective default values; they can be reused.
|
|
*
|
|
* Tests can be found in ./tests.nix
|
|
* Documentation in the manual, #sec-generators
|
|
*/
|
|
{ lib }:
|
|
with (lib).trivial;
|
|
let
|
|
libStr = lib.strings;
|
|
libAttr = lib.attrsets;
|
|
|
|
flipMapAttrs = flip libAttr.mapAttrs;
|
|
|
|
inherit (lib) isFunction;
|
|
in
|
|
|
|
rec {
|
|
|
|
## -- HELPER FUNCTIONS & DEFAULTS --
|
|
|
|
/* Convert a value to a sensible default string representation.
|
|
* The builtin `toString` function has some strange defaults,
|
|
* suitable for bash scripts but not much else.
|
|
*/
|
|
mkValueStringDefault = {}: v: with builtins;
|
|
let err = t: v: abort
|
|
("generators.mkValueStringDefault: " +
|
|
"${t} not supported: ${toPretty {} v}");
|
|
in if isInt v then toString v
|
|
# we default to not quoting strings
|
|
else if isString v then v
|
|
# isString returns "1", which is not a good default
|
|
else if true == v then "true"
|
|
# here it returns to "", which is even less of a good default
|
|
else if false == v then "false"
|
|
else if null == v then "null"
|
|
# if you have lists you probably want to replace this
|
|
else if isList v then err "lists" v
|
|
# same as for lists, might want to replace
|
|
else if isAttrs v then err "attrsets" v
|
|
else if isFunction v then err "functions" v
|
|
else err "this value is" (toString v);
|
|
|
|
|
|
/* Generate a line of key k and value v, separated by
|
|
* character sep. If sep appears in k, it is escaped.
|
|
* Helper for synaxes with different separators.
|
|
*
|
|
* mkValueString specifies how values should be formatted.
|
|
*
|
|
* mkKeyValueDefault {} ":" "f:oo" "bar"
|
|
* > "f\:oo:bar"
|
|
*/
|
|
mkKeyValueDefault = {
|
|
mkValueString ? mkValueStringDefault {}
|
|
}: sep: k: v:
|
|
"${libStr.escape [sep] k}${sep}${mkValueString v}";
|
|
|
|
|
|
## -- FILE FORMAT GENERATORS --
|
|
|
|
|
|
/* Generate a key-value-style config file from an attrset.
|
|
*
|
|
* mkKeyValue is the same as in toINI.
|
|
*/
|
|
toKeyValue = {
|
|
mkKeyValue ? mkKeyValueDefault {} "="
|
|
}: attrs:
|
|
let mkLine = k: v: mkKeyValue k v + "\n";
|
|
in libStr.concatStrings (libAttr.mapAttrsToList mkLine attrs);
|
|
|
|
|
|
/* Generate an INI-style config file from an
|
|
* attrset of sections to an attrset of key-value pairs.
|
|
*
|
|
* generators.toINI {} {
|
|
* foo = { hi = "${pkgs.hello}"; ciao = "bar"; };
|
|
* baz = { "also, integers" = 42; };
|
|
* }
|
|
*
|
|
*> [baz]
|
|
*> also, integers=42
|
|
*>
|
|
*> [foo]
|
|
*> ciao=bar
|
|
*> hi=/nix/store/y93qql1p5ggfnaqjjqhxcw0vqw95rlz0-hello-2.10
|
|
*
|
|
* The mk* configuration attributes can generically change
|
|
* the way sections and key-value strings are generated.
|
|
*
|
|
* For more examples see the test cases in ./tests.nix.
|
|
*/
|
|
toINI = {
|
|
# apply transformations (e.g. escapes) to section names
|
|
mkSectionName ? (name: libStr.escape [ "[" "]" ] name),
|
|
# format a setting line from key and value
|
|
mkKeyValue ? mkKeyValueDefault {} "="
|
|
}: attrsOfAttrs:
|
|
let
|
|
# map function to string for each key val
|
|
mapAttrsToStringsSep = sep: mapFn: attrs:
|
|
libStr.concatStringsSep sep
|
|
(libAttr.mapAttrsToList mapFn attrs);
|
|
mkSection = sectName: sectValues: ''
|
|
[${mkSectionName sectName}]
|
|
'' + toKeyValue { inherit mkKeyValue; } sectValues;
|
|
in
|
|
# map input to ini sections
|
|
mapAttrsToStringsSep "\n" mkSection attrsOfAttrs;
|
|
|
|
|
|
/* Generates JSON from an arbitrary (non-function) value.
|
|
* For more information see the documentation of the builtin.
|
|
*/
|
|
toJSON = {}: builtins.toJSON;
|
|
|
|
|
|
/* YAML has been a strict superset of JSON since 1.2, so we
|
|
* use toJSON. Before it only had a few differences referring
|
|
* to implicit typing rules, so it should work with older
|
|
* parsers as well.
|
|
*/
|
|
toYAML = {}@args: toJSON args;
|
|
|
|
|
|
/* Pretty print a value, akin to `builtins.trace`.
|
|
* Should probably be a builtin as well.
|
|
*/
|
|
toPretty = {
|
|
/* If this option is true, attrsets like { __pretty = fn; val = …; }
|
|
will use fn to convert val to a pretty printed representation.
|
|
(This means fn is type Val -> String.) */
|
|
allowPrettyValues ? false
|
|
}@args: v: with builtins;
|
|
let isPath = v: typeOf v == "path";
|
|
in if isInt v then toString v
|
|
else if isString v then ''"${libStr.escape [''"''] v}"''
|
|
else if true == v then "true"
|
|
else if false == v then "false"
|
|
else if null == v then "null"
|
|
else if isPath v then toString v
|
|
else if isList v then "[ "
|
|
+ libStr.concatMapStringsSep " " (toPretty args) v
|
|
+ " ]"
|
|
else if isAttrs v then
|
|
# apply pretty values if allowed
|
|
if attrNames v == [ "__pretty" "val" ] && allowPrettyValues
|
|
then v.__pretty v.val
|
|
# TODO: there is probably a better representation?
|
|
else if v ? type && v.type == "derivation" then
|
|
"<δ:${v.name}>"
|
|
# "<δ:${concatStringsSep "," (builtins.attrNames v)}>"
|
|
else "{ "
|
|
+ libStr.concatStringsSep " " (libAttr.mapAttrsToList
|
|
(name: value:
|
|
"${toPretty args name} = ${toPretty args value};") v)
|
|
+ " }"
|
|
else if isFunction v then
|
|
let fna = lib.functionArgs v;
|
|
showFnas = concatStringsSep "," (libAttr.mapAttrsToList
|
|
(name: hasDefVal: if hasDefVal then "(${name})" else name)
|
|
fna);
|
|
in if fna == {} then "<λ>"
|
|
else "<λ:{${showFnas}}>"
|
|
else abort "toPretty: should never happen (v = ${v})";
|
|
|
|
# PLIST handling
|
|
|
|
toPLIST = x: ''
|
|
<?xml version="1.0" encoding="UTF-8"?>
|
|
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
|
|
<plist version="1.0">
|
|
'' + pprExpr "" x
|
|
+ "\n</plist>";
|
|
|
|
pprExpr = ind: x: with builtins;
|
|
if isNull x then "" else
|
|
if isBool x then pprBool ind x else
|
|
if isInt x then pprInt ind x else
|
|
if isString x then pprStr ind x else
|
|
if isList x then pprList ind x else
|
|
if isAttrs x then pprAttrs ind x else
|
|
throw "invalid plist type";
|
|
|
|
pprLiteral = ind: x: ind + x;
|
|
|
|
pprBool = ind: x: pprLiteral ind (if x then "<true/>" else "<false/>");
|
|
pprInt = ind: x: pprLiteral ind "<integer>${toString x}</integer>";
|
|
pprStr = ind: x: pprLiteral ind "<string>${x}</string>";
|
|
pprKey = ind: x: pprLiteral ind "<key>${x}</key>";
|
|
|
|
pprIndent = ind: pprExpr "\t${ind}";
|
|
|
|
pprItem = ind: libStr.concatMapStringsSep "\n" (pprIndent ind);
|
|
|
|
pprList = ind: x: libStr.concatStringsSep "\n" [
|
|
(pprLiteral ind "<array>")
|
|
(pprItem ind x)
|
|
(pprLiteral ind "</array>")
|
|
];
|
|
|
|
pprAttrs = ind: x: libStr.concatStringsSep "\n" [
|
|
(pprLiteral ind "<dict>")
|
|
(pprAttr ind x)
|
|
(pprLiteral ind "</dict>")
|
|
];
|
|
|
|
attrFilter = name: value: name != "_module" && value != null;
|
|
|
|
pprAttr = ind: x: libStr.concatStringsSep "\n" (lib.flatten (lib.mapAttrsToList (name: value: lib.optional (attrFilter name value) [
|
|
(pprKey "\t${ind}" name)
|
|
(pprExpr "\t${ind}" value)
|
|
]) x));
|
|
|
|
}
|