1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
|
# Definitions related to run-time type checking. Used in particular
# to type-check NixOS configurations.
with import ./lists.nix;
with import ./attrsets.nix;
with import ./options.nix;
with import ./trivial.nix;
with import ./strings.nix;
let inherit (import ./modules.nix) mergeDefinitions filterOverrides; in
rec {
isType = type: x: (x._type or "") == type;
setType = typeName: value: value // {
_type = typeName;
};
# Default type merging function
# takes two type functors and return the merged type
defaultTypeMerge = f: f':
let wrapped = f.wrapped.typeMerge f'.wrapped.functor;
payload = f.binOp f.payload f'.payload;
in
# cannot merge different types
if f.name != f'.name
then null
# simple types
else if (f.wrapped == null && f'.wrapped == null)
&& (f.payload == null && f'.payload == null)
then f.type
# composed types
else if (f.wrapped != null && f'.wrapped != null) && (wrapped != null)
then f.type wrapped
# value types
else if (f.payload != null && f'.payload != null) && (payload != null)
then f.type payload
else null;
# Default type functor
defaultFunctor = name: {
inherit name;
type = types."${name}" or null;
wrapped = null;
payload = null;
binOp = a: b: null;
};
isOptionType = isType "option-type";
mkOptionType =
{ # Human-readable representation of the type, should be equivalent to
# the type function name.
name
, # Description of the type, defined recursively by embedding the wrapped type if any.
description ? null
, # Function applied to each definition that should return true if
# its type-correct, false otherwise.
check ? (x: true)
, # Merge a list of definitions together into a single value.
# This function is called with two arguments: the location of
# the option in the configuration as a list of strings
# (e.g. ["boot" "loader "grub" "enable"]), and a list of
# definition values and locations (e.g. [ { file = "/foo.nix";
# value = 1; } { file = "/bar.nix"; value = 2 } ]).
merge ? mergeDefaultOption
, # Return a flat list of sub-options. Used to generate
# documentation.
getSubOptions ? prefix: {}
, # List of modules if any, or null if none.
getSubModules ? null
, # Function for building the same option type with a different list of
# modules.
substSubModules ? m: null
, # Function that merge type declarations.
# internal, takes a functor as argument and returns the merged type.
# returning null means the type is not mergeable
typeMerge ? defaultTypeMerge functor
, # The type functor.
# internal, representation of the type as an attribute set.
# name: name of the type
# type: type function.
# wrapped: the type wrapped in case of compound types.
# payload: values of the type, two payloads of the same type must be
# combinable with the binOp binary operation.
# binOp: binary operation that merge two payloads of the same type.
functor ? defaultFunctor name
}:
{ _type = "option-type";
inherit name check merge getSubOptions getSubModules substSubModules typeMerge functor;
description = if description == null then name else description;
};
# When adding new types don't forget to document them in
# nixos/doc/manual/development/option-types.xml!
types = rec {
unspecified = mkOptionType {
name = "unspecified";
};
bool = mkOptionType {
name = "bool";
description = "boolean";
check = isBool;
merge = mergeEqualOption;
};
int = mkOptionType rec {
name = "int";
description = "integer";
check = isInt;
merge = mergeOneOption;
};
str = mkOptionType {
name = "str";
description = "string";
check = isString;
merge = mergeOneOption;
};
# Merge multiple definitions by concatenating them (with the given
# separator between the values).
separatedString = sep: mkOptionType rec {
name = "separatedString";
description = "string";
check = isString;
merge = loc: defs: concatStringsSep sep (getValues defs);
functor = (defaultFunctor name) // {
payload = sep;
binOp = sepLhs: sepRhs:
if sepLhs == sepRhs then sepLhs
else null;
};
};
lines = separatedString "\n";
commas = separatedString ",";
envVar = separatedString ":";
# Deprecated; should not be used because it quietly concatenates
# strings, which is usually not what you want.
string = separatedString "";
attrs = mkOptionType {
name = "attrs";
description = "attribute set";
check = isAttrs;
merge = loc: foldl' (res: def: mergeAttrs res def.value) {};
};
# derivation is a reserved keyword.
package = mkOptionType {
name = "package";
check = x: isDerivation x || isStorePath x;
merge = loc: defs:
let res = mergeOneOption loc defs;
in if isDerivation res then res else toDerivation res;
};
shellPackage = package // {
check = x: (package.check x) && (hasAttr "shellPath" x);
};
path = mkOptionType {
name = "path";
# Hacky: there is no ‘isPath’ primop.
check = x: builtins.substring 0 1 (toString x) == "/";
merge = mergeOneOption;
};
# drop this in the future:
list = builtins.trace "`types.list' is deprecated; use `types.listOf' instead" types.listOf;
listOf = elemType: mkOptionType rec {
name = "listOf";
description = "list of ${elemType.description}s";
check = isList;
merge = loc: defs:
map (x: x.value) (filter (x: x ? value) (concatLists (imap (n: def:
if isList def.value then
imap (m: def':
(mergeDefinitions
(loc ++ ["[definition ${toString n}-entry ${toString m}]"])
elemType
[{ inherit (def) file; value = def'; }]
).optionalValue
) def.value
else
throw "The option value `${showOption loc}' in `${def.file}' is not a list.") defs)));
getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["*"]);
getSubModules = elemType.getSubModules;
substSubModules = m: listOf (elemType.substSubModules m);
functor = (defaultFunctor name) // { wrapped = elemType; };
};
attrsOf = elemType: mkOptionType rec {
name = "attrsOf";
description = "attribute set of ${elemType.description}s";
check = isAttrs;
merge = loc: defs:
mapAttrs (n: v: v.value) (filterAttrs (n: v: v ? value) (zipAttrsWith (name: defs:
(mergeDefinitions (loc ++ [name]) elemType defs).optionalValue
)
# Push down position info.
(map (def: listToAttrs (mapAttrsToList (n: def':
{ name = n; value = { inherit (def) file; value = def'; }; }) def.value)) defs)));
getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["<name>"]);
getSubModules = elemType.getSubModules;
substSubModules = m: attrsOf (elemType.substSubModules m);
functor = (defaultFunctor name) // { wrapped = elemType; };
};
# List or attribute set of ...
loaOf = elemType:
let
convertIfList = defIdx: def:
if isList def.value then
{ inherit (def) file;
value = listToAttrs (
imap (elemIdx: elem:
{ name = elem.name or "unnamed-${toString defIdx}.${toString elemIdx}";
value = elem;
}) def.value);
}
else
def;
listOnly = listOf elemType;
attrOnly = attrsOf elemType;
in mkOptionType rec {
name = "loaOf";
description = "list or attribute set of ${elemType.description}s";
check = x: isList x || isAttrs x;
merge = loc: defs: attrOnly.merge loc (imap convertIfList defs);
getSubOptions = prefix: elemType.getSubOptions (prefix ++ ["<name?>"]);
getSubModules = elemType.getSubModules;
substSubModules = m: loaOf (elemType.substSubModules m);
functor = (defaultFunctor name) // { wrapped = elemType; };
};
# List or element of ...
loeOf = elemType: mkOptionType rec {
name = "loeOf";
description = "element or list of ${elemType.description}s";
check = x: isList x || elemType.check x;
merge = loc: defs:
let
defs' = filterOverrides defs;
res = (head defs').value;
in
if isList res then concatLists (getValues defs')
else if lessThan 1 (length defs') then
throw "The option `${showOption loc}' is defined multiple times, in ${showFiles (getFiles defs)}."
else if !isString res then
throw "The option `${showOption loc}' does not have a string value, in ${showFiles (getFiles defs)}."
else res;
functor = (defaultFunctor name) // { wrapped = elemType; };
};
uniq = elemType: mkOptionType rec {
name = "uniq";
inherit (elemType) description check;
merge = mergeOneOption;
getSubOptions = elemType.getSubOptions;
getSubModules = elemType.getSubModules;
substSubModules = m: uniq (elemType.substSubModules m);
functor = (defaultFunctor name) // { wrapped = elemType; };
};
nullOr = elemType: mkOptionType rec {
name = "nullOr";
description = "null or ${elemType.description}";
check = x: x == null || elemType.check x;
merge = loc: defs:
let nrNulls = count (def: def.value == null) defs; in
if nrNulls == length defs then null
else if nrNulls != 0 then
throw "The option `${showOption loc}' is defined both null and not null, in ${showFiles (getFiles defs)}."
else elemType.merge loc defs;
getSubOptions = elemType.getSubOptions;
getSubModules = elemType.getSubModules;
substSubModules = m: nullOr (elemType.substSubModules m);
functor = (defaultFunctor name) // { wrapped = elemType; };
};
submodule = opts:
let
opts' = toList opts;
inherit (import ./modules.nix) evalModules;
in
mkOptionType rec {
name = "submodule";
check = x: isAttrs x || isFunction x;
merge = loc: defs:
let
coerce = def: if isFunction def then def else { config = def; };
modules = opts' ++ map (def: { _file = def.file; imports = [(coerce def.value)]; }) defs;
in (evalModules {
inherit modules;
args.name = last loc;
prefix = loc;
}).config;
getSubOptions = prefix: (evalModules
{ modules = opts'; inherit prefix;
# FIXME: hack to get shit to evaluate.
args = { name = ""; }; }).options;
getSubModules = opts';
substSubModules = m: submodule m;
functor = (defaultFunctor name) // {
# Merging of submodules is done as part of mergeOptionDecls, as we have to annotate
# each submodule with its location.
payload = [];
binOp = lhs: rhs: [];
};
};
enum = values:
let
show = v:
if builtins.isString v then ''"${v}"''
else if builtins.isInt v then builtins.toString v
else ''<${builtins.typeOf v}>'';
in
mkOptionType rec {
name = "enum";
description = "one of ${concatMapStringsSep ", " show values}";
check = flip elem values;
merge = mergeOneOption;
functor = (defaultFunctor name) // { payload = values; binOp = a: b: unique (a ++ b); };
};
either = t1: t2: mkOptionType rec {
name = "either";
description = "${t1.description} or ${t2.description}";
check = x: t1.check x || t2.check x;
merge = loc: defs:
let
defList = map (d: d.value) defs;
in
if all (x: t1.check x) defList
then t1.merge loc defs
else if all (x: t2.check x) defList
then t2.merge loc defs
else mergeOneOption loc defs;
typeMerge = f':
let mt1 = t1.typeMerge (elemAt f'.wrapped 0).functor;
mt2 = t2.typeMerge (elemAt f'.wrapped 1).functor;
in
if (name == f'.name) && (mt1 != null) && (mt2 != null)
then functor.type mt1 mt2
else null;
functor = (defaultFunctor name) // { wrapped = [ t1 t2 ]; };
};
coercedTo = coercedType: coerceFunc: finalType:
assert coercedType.getSubModules == null;
mkOptionType rec {
name = "coercedTo";
description = "${finalType.description} or ${coercedType.description}";
check = x: finalType.check x || coercedType.check x;
merge = loc: defs:
let
coerceVal = val:
if finalType.check val then val
else let
coerced = coerceFunc val;
in assert finalType.check coerced; coerced;
in finalType.merge loc (map (def: def // { value = coerceVal def.value; }) defs);
getSubOptions = finalType.getSubOptions;
getSubModules = finalType.getSubModules;
substSubModules = m: coercedTo coercedType coerceFunc (finalType.substSubModules m);
typeMerge = t1: t2: null;
functor = (defaultFunctor name) // { wrapped = finalType; };
};
# Obsolete alternative to configOf. It takes its option
# declarations from the ‘options’ attribute of containing option
# declaration.
optionSet = mkOptionType {
name = builtins.trace "types.optionSet is deprecated; use types.submodule instead" "optionSet";
description = "option set";
};
# Augment the given type with an additional type check function.
addCheck = elemType: check: elemType // { check = x: elemType.check x && check x; };
};
}
|