ee4f8c2dc9
Also mention about docs in types.nix and fix a small error in related documentation. Fixes #26055.
392 lines
14 KiB
Nix
392 lines
14 KiB
Nix
# 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; };
|
||
|
||
};
|
||
|
||
}
|