nixpkgs/lib/gvariant.nix

350 lines
9 KiB
Nix
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
A partial and basic implementation of GVariant formatted strings.
See [GVariant Format Strings](https://docs.gtk.org/glib/gvariant-format-strings.html) for details.
:::{.warning}
This API is not considered fully stable and it might therefore
change in backwards incompatible ways without prior notice.
:::
*/
# This file is based on https://github.com/nix-community/home-manager
# Copyright (c) 2017-2022 Home Manager contributors
{ lib }:
let
inherit (lib)
concatMapStringsSep concatStrings escape head replaceStrings;
mkPrimitive = t: v: {
_type = "gvariant";
type = t;
value = v;
__toString = self: "@${self.type} ${toString self.value}"; # https://docs.gtk.org/glib/gvariant-text.html
};
type = {
arrayOf = t: "a${t}";
maybeOf = t: "m${t}";
tupleOf = ts: "(${concatStrings ts})";
dictionaryEntryOf = nameType: valueType: "{${nameType}${valueType}}";
string = "s";
boolean = "b";
uchar = "y";
int16 = "n";
uint16 = "q";
int32 = "i";
uint32 = "u";
int64 = "x";
uint64 = "t";
double = "d";
variant = "v";
};
/* Check if a value is a GVariant value
Type:
isGVariant :: Any -> Bool
*/
isGVariant = v: v._type or "" == "gvariant";
in
rec {
inherit type isGVariant;
intConstructors = [
{
name = "mkInt32";
type = type.int32;
min = -2147483648;
max = 2147483647;
}
{
name = "mkUint32";
type = type.uint32;
min = 0;
max = 4294967295;
}
{
name = "mkInt64";
type = type.int64;
# Nix does not support such large numbers.
min = null;
max = null;
}
{
name = "mkUint64";
type = type.uint64;
min = 0;
# Nix does not support such large numbers.
max = null;
}
{
name = "mkInt16";
type = type.int16;
min = -32768;
max = 32767;
}
{
name = "mkUint16";
type = type.uint16;
min = 0;
max = 65535;
}
{
name = "mkUchar";
type = type.uchar;
min = 0;
max = 255;
}
];
/* Returns the GVariant value that most closely matches the given Nix value.
If no GVariant value can be found unambiguously then error is thrown.
Type:
mkValue :: Any -> gvariant
*/
mkValue = v:
if builtins.isBool v then
mkBoolean v
else if builtins.isFloat v then
mkDouble v
else if builtins.isString v then
mkString v
else if builtins.isList v then
mkArray v
else if isGVariant v then
v
else if builtins.isInt v then
let
validConstructors = builtins.filter ({ min, max, ... }: (min == null || min <= v) && (max == null || v <= max)) intConstructors;
in
throw ''
The GVariant type for number ${builtins.toString v} is unclear.
Please wrap the value with one of the following, depending on the value type in GSettings schema:
${lib.concatMapStringsSep "\n" ({ name, type, ...}: "- `lib.gvariant.${name}` for `${type}`") validConstructors}
''
else if builtins.isAttrs v then
throw "Cannot construct GVariant value from an attribute set. If you want to construct a dictionary, you will need to create an array containing items constructed with `lib.gvariant.mkDictionaryEntry`."
else
throw "The GVariant type of ${builtins.typeOf v} can't be inferred.";
/* Returns the GVariant array from the given type of the elements and a Nix list.
Type:
mkArray :: [Any] -> gvariant
Example:
# Creating a string array
lib.gvariant.mkArray [ "a" "b" "c" ]
*/
mkArray = elems:
let
vs = map mkValue (lib.throwIf (elems == [ ]) "Please create empty array with mkEmptyArray." elems);
elemType = lib.throwIfNot (lib.all (t: (head vs).type == t) (map (v: v.type) vs))
"Elements in a list should have same type."
(head vs).type;
in
mkPrimitive (type.arrayOf elemType) vs // {
__toString = self:
"@${self.type} [${concatMapStringsSep "," toString self.value}]";
};
/* Returns the GVariant array from the given empty Nix list.
Type:
mkEmptyArray :: gvariant.type -> gvariant
Example:
# Creating an empty string array
lib.gvariant.mkEmptyArray (lib.gvariant.type.string)
*/
mkEmptyArray = elemType: mkPrimitive (type.arrayOf elemType) [ ] // {
__toString = self: "@${self.type} []";
};
/* Returns the GVariant variant from the given Nix value. Variants are containers
of different GVariant type.
Type:
mkVariant :: Any -> gvariant
Example:
lib.gvariant.mkArray [
(lib.gvariant.mkVariant "a string")
(lib.gvariant.mkVariant (lib.gvariant.mkInt32 1))
]
*/
mkVariant = elem:
let gvarElem = mkValue elem;
in mkPrimitive type.variant gvarElem // {
__toString = self: "<${toString self.value}>";
};
/* Returns the GVariant dictionary entry from the given key and value.
Type:
mkDictionaryEntry :: String -> Any -> gvariant
Example:
# A dictionary describing an Epiphanys search provider
[
(lib.gvariant.mkDictionaryEntry "url" (lib.gvariant.mkVariant "https://duckduckgo.com/?q=%s&t=epiphany"))
(lib.gvariant.mkDictionaryEntry "bang" (lib.gvariant.mkVariant "!d"))
(lib.gvariant.mkDictionaryEntry "name" (lib.gvariant.mkVariant "DuckDuckGo"))
]
*/
mkDictionaryEntry =
# The key of the entry
name:
# The value of the entry
value:
let
name' = mkValue name;
value' = mkValue value;
dictionaryType = type.dictionaryEntryOf name'.type value'.type;
in
mkPrimitive dictionaryType { inherit name value; } // {
__toString = self: "@${self.type} {${name'},${value'}}";
};
/* Returns the GVariant maybe from the given element type.
Type:
mkMaybe :: gvariant.type -> Any -> gvariant
*/
mkMaybe = elemType: elem:
mkPrimitive (type.maybeOf elemType) elem // {
__toString = self:
if self.value == null then
"@${self.type} nothing"
else
"just ${toString self.value}";
};
/* Returns the GVariant nothing from the given element type.
Type:
mkNothing :: gvariant.type -> gvariant
*/
mkNothing = elemType: mkMaybe elemType null;
/* Returns the GVariant just from the given Nix value.
Type:
mkJust :: Any -> gvariant
*/
mkJust = elem: let gvarElem = mkValue elem; in mkMaybe gvarElem.type gvarElem;
/* Returns the GVariant tuple from the given Nix list.
Type:
mkTuple :: [Any] -> gvariant
*/
mkTuple = elems:
let
gvarElems = map mkValue elems;
tupleType = type.tupleOf (map (e: e.type) gvarElems);
in
mkPrimitive tupleType gvarElems // {
__toString = self:
"@${self.type} (${concatMapStringsSep "," toString self.value})";
};
/* Returns the GVariant boolean from the given Nix bool value.
Type:
mkBoolean :: Bool -> gvariant
*/
mkBoolean = v:
mkPrimitive type.boolean v // {
__toString = self: if self.value then "true" else "false";
};
/* Returns the GVariant string from the given Nix string value.
Type:
mkString :: String -> gvariant
*/
mkString = v:
let sanitize = s: replaceStrings [ "\n" ] [ "\\n" ] (escape [ "'" "\\" ] s);
in mkPrimitive type.string v // {
__toString = self: "'${sanitize self.value}'";
};
/* Returns the GVariant object path from the given Nix string value.
Type:
mkObjectpath :: String -> gvariant
*/
mkObjectpath = v:
mkPrimitive type.string v // {
__toString = self: "objectpath '${escape [ "'" ] self.value}'";
};
/* Returns the GVariant uchar from the given Nix int value.
Type:
mkUchar :: Int -> gvariant
*/
mkUchar = mkPrimitive type.uchar;
/* Returns the GVariant int16 from the given Nix int value.
Type:
mkInt16 :: Int -> gvariant
*/
mkInt16 = mkPrimitive type.int16;
/* Returns the GVariant uint16 from the given Nix int value.
Type:
mkUint16 :: Int -> gvariant
*/
mkUint16 = mkPrimitive type.uint16;
/* Returns the GVariant int32 from the given Nix int value.
Type:
mkInt32 :: Int -> gvariant
*/
mkInt32 = v:
mkPrimitive type.int32 v // {
__toString = self: toString self.value;
};
/* Returns the GVariant uint32 from the given Nix int value.
Type:
mkUint32 :: Int -> gvariant
*/
mkUint32 = mkPrimitive type.uint32;
/* Returns the GVariant int64 from the given Nix int value.
Type:
mkInt64 :: Int -> gvariant
*/
mkInt64 = mkPrimitive type.int64;
/* Returns the GVariant uint64 from the given Nix int value.
Type:
mkUint64 :: Int -> gvariant
*/
mkUint64 = mkPrimitive type.uint64;
/* Returns the GVariant double from the given Nix float value.
Type:
mkDouble :: Float -> gvariant
*/
mkDouble = v:
mkPrimitive type.double v // {
__toString = self: toString self.value;
};
}