866 lines
27 KiB
Nix
866 lines
27 KiB
Nix
# Nixpkgs/NixOS option handling.
|
|
|
|
let lib = import ./default.nix; in
|
|
|
|
with { inherit (builtins) head tail; };
|
|
with import ./trivial.nix;
|
|
with import ./lists.nix;
|
|
with import ./misc.nix;
|
|
with import ./attrsets.nix;
|
|
|
|
rec {
|
|
|
|
|
|
hasType = x: isAttrs x && x ? _type;
|
|
typeOf = x: if hasType x then x._type else "";
|
|
|
|
isOption = attrs: (typeOf attrs) == "option";
|
|
mkOption = attrs: attrs // {
|
|
_type = "option";
|
|
# name (this is the name of the attributem it is automatically generated by the traversal)
|
|
# default (value used when no definition exists)
|
|
# example (documentation)
|
|
# description (documentation)
|
|
# type (option type, provide a default merge function and ensure type correctness)
|
|
# merge (function used to merge definitions into one definition: [ /type/ ] -> /type/)
|
|
# apply (convert the option value to ease the manipulation of the option result)
|
|
# options (set of sub-options declarations & definitions)
|
|
};
|
|
|
|
# Make the option declaration more user-friendly by adding default
|
|
# settings and some verifications based on the declaration content (like
|
|
# type correctness).
|
|
addOptionMakeUp = {name, recurseInto}: decl:
|
|
let
|
|
init = {
|
|
inherit name;
|
|
merge = mergeDefaultOption;
|
|
apply = lib.id;
|
|
};
|
|
|
|
mergeFromType = opt:
|
|
if decl ? type && decl.type ? merge then
|
|
opt // { merge = decl.type.merge; }
|
|
else
|
|
opt;
|
|
|
|
addDeclaration = opt: opt // decl;
|
|
|
|
ensureMergeInputType = opt:
|
|
if decl ? type then
|
|
opt // {
|
|
merge = list:
|
|
if all decl.type.check list then
|
|
opt.merge list
|
|
else
|
|
throw "One of the definitions has a bad type.";
|
|
}
|
|
else opt;
|
|
|
|
ensureDefaultType = opt:
|
|
if decl ? type && decl ? default then
|
|
opt // {
|
|
default =
|
|
if decl.type.check decl.default then
|
|
decl.default
|
|
else
|
|
throw "The default value has a bad type.";
|
|
}
|
|
else opt;
|
|
|
|
handleOptionSets = opt:
|
|
if decl ? type && decl.type.hasOptions then
|
|
let
|
|
optionConfig = opts: config:
|
|
map (f: applyIfFunction f config)
|
|
(decl.options ++ [opts]);
|
|
in
|
|
opt // {
|
|
merge = list:
|
|
decl.type.iter
|
|
(path: opts:
|
|
fixMergeFun (recurseInto path) (optionConfig opts)
|
|
)
|
|
opt.name
|
|
(opt.merge list);
|
|
options = recurseInto (decl.type.docPath opt.name) decl.options;
|
|
}
|
|
else
|
|
opt;
|
|
in
|
|
foldl (opt: f: f opt) init [
|
|
# default settings
|
|
mergeFromType
|
|
|
|
# user settings
|
|
addDeclaration
|
|
|
|
# override settings
|
|
ensureMergeInputType
|
|
ensureDefaultType
|
|
handleOptionSets
|
|
];
|
|
|
|
# Merge a list of options containning different field. This is useful to
|
|
# separate the merge & apply fields from the interface.
|
|
mergeOptionDecls = opts:
|
|
if opts == [] then {}
|
|
else if tail opts == [] then
|
|
let opt = head opts; in
|
|
if opt ? options then
|
|
opt // { options = toList opt.options; }
|
|
else
|
|
opt
|
|
else
|
|
fold (opt1: opt2:
|
|
lib.addErrorContext "opt1 = ${lib.showVal opt1}\nopt2 = ${lib.showVal opt2}" (
|
|
# You cannot merge if two options have the same field.
|
|
assert opt1 ? default -> ! opt2 ? default;
|
|
assert opt1 ? example -> ! opt2 ? example;
|
|
assert opt1 ? description -> ! opt2 ? description;
|
|
assert opt1 ? merge -> ! opt2 ? merge;
|
|
assert opt1 ? apply -> ! opt2 ? apply;
|
|
assert opt1 ? type -> ! opt2 ? type;
|
|
if opt1 ? options || opt2 ? options then
|
|
opt1 // opt2 // {
|
|
options =
|
|
(toList (attrByPath ["options"] [] opt1))
|
|
++ (toList (attrByPath ["options"] [] opt2));
|
|
}
|
|
else
|
|
opt1 // opt2
|
|
)) {} opts;
|
|
|
|
|
|
# name (name of the type)
|
|
# check (boolean function)
|
|
# merge (default merge function)
|
|
# iter (iterate on all elements contained in this type)
|
|
# fold (fold all elements contained in this type)
|
|
# hasOptions (boolean: whatever this option contains an option set)
|
|
# path (path contatenated to the option name contained contained in the option set)
|
|
isOptionType = attrs: (typeOf attrs) == "option-type";
|
|
mkOptionType = attrs@{
|
|
name
|
|
, check ? (x: true)
|
|
, merge ? mergeDefaultOption
|
|
# Handle complex structure types.
|
|
, iter ? (f: path: v: f path v)
|
|
, fold ? (op: nul: v: op v nul)
|
|
, docPath ? lib.id
|
|
# If the type can contains option sets.
|
|
, hasOptions ? false
|
|
}: { _type = "option-type";
|
|
inherit name check merge iter fold docPath hasOptions;
|
|
};
|
|
|
|
|
|
types = {
|
|
|
|
inferred = mkOptionType {
|
|
name = "inferred type";
|
|
};
|
|
|
|
bool = mkOptionType {
|
|
name = "boolean";
|
|
check = builtins.isBool;
|
|
merge = fold lib.or false;
|
|
};
|
|
|
|
int = mkOptionType {
|
|
name = "integer";
|
|
check = builtins.isInt;
|
|
};
|
|
|
|
string = mkOptionType {
|
|
name = "string";
|
|
check = x: builtins ? isString -> builtins.isString x;
|
|
merge = lib.concatStrings;
|
|
};
|
|
|
|
attrs = mkOptionType {
|
|
name = "attribute set";
|
|
check = builtins.isAttrs;
|
|
merge = fold lib.mergeAttrs {};
|
|
};
|
|
|
|
# derivation is a reserved keyword.
|
|
package = mkOptionType {
|
|
name = "derivation";
|
|
check = x: builtins.isAttrs x && x ? outPath;
|
|
};
|
|
|
|
|
|
list = elemType: mkOptionType {
|
|
name = "list of ${elemType.name}s";
|
|
check = value: isList value && all elemType.check value;
|
|
merge = concatLists;
|
|
iter = f: path: list: map (elemType.iter f (path + ".*")) list;
|
|
fold = op: nul: list: lib.fold (e: l: elemType.fold op l e) nul list;
|
|
docPath = path: elemType.docPath (path + ".*");
|
|
inherit (elemType) hasOptions;
|
|
};
|
|
|
|
attrsOf = elemType: mkOptionType {
|
|
name = "attribute set of ${elemType}s";
|
|
check = x: builtins.isAttrs x
|
|
&& fold (e: v: v && elemType.check e) true (lib.attrValues x);
|
|
merge = fold lib.mergeAttrs {};
|
|
iter = f: path: set: lib.mapAttrs (name: elemType.iter f (path + "." + name)) set;
|
|
fold = op: nul: set: fold (e: l: elemType.fold op l e) nul (lib.attrValues set);
|
|
docPath = path: elemType.docPath (path + ".<name>");
|
|
inherit (elemType) hasOptions;
|
|
};
|
|
|
|
uniq = elemType: mkOptionType {
|
|
inherit (elemType) name check iter fold docPath hasOptions;
|
|
merge = list:
|
|
if tail list == [] then
|
|
head list
|
|
else
|
|
throw "Multiple definitions. Only one is allowed for this option.";
|
|
};
|
|
|
|
nullOr = elemType: mkOptionType {
|
|
inherit (elemType) name merge docPath hasOptions;
|
|
check = x: builtins.isNull x || elemType.check x;
|
|
iter = f: path: v: if v == null then v else elemType.iter f path v;
|
|
fold = op: nul: v: if v == null then nul else elemType.fold op nul v;
|
|
};
|
|
|
|
optionSet = mkOptionType {
|
|
name = "option set";
|
|
check = x: builtins.isAttrs x;
|
|
hasOptions = true;
|
|
};
|
|
|
|
};
|
|
|
|
|
|
# !!! This function will be removed because this can be done with the
|
|
# multiple option declarations.
|
|
addDefaultOptionValues = defs: opts: opts //
|
|
builtins.listToAttrs (map (defName:
|
|
{ name = defName;
|
|
value =
|
|
let
|
|
defValue = builtins.getAttr defName defs;
|
|
optValue = builtins.getAttr defName opts;
|
|
in
|
|
if typeOf defValue == "option"
|
|
then
|
|
# `defValue' is an option.
|
|
if hasAttr defName opts
|
|
then builtins.getAttr defName opts
|
|
else defValue.default
|
|
else
|
|
# `defValue' is an attribute set containing options.
|
|
# So recurse.
|
|
if hasAttr defName opts && isAttrs optValue
|
|
then addDefaultOptionValues defValue optValue
|
|
else addDefaultOptionValues defValue {};
|
|
}
|
|
) (attrNames defs));
|
|
|
|
mergeDefaultOption = list:
|
|
if list != [] && tail list == [] then head list
|
|
else if all builtins.isFunction list then x: mergeDefaultOption (map (f: f x) list)
|
|
else if all isList list then concatLists list
|
|
else if all isAttrs list then fold lib.mergeAttrs {} list
|
|
else if all (x: true == x || false == x) list then fold lib.or false list
|
|
else if all (x: x == toString x) list then lib.concatStrings list
|
|
else throw "Cannot merge values.";
|
|
|
|
mergeTypedOption = typeName: predicate: merge: list:
|
|
if all predicate list then merge list
|
|
else throw "Expect a ${typeName}.";
|
|
|
|
mergeEnableOption = mergeTypedOption "boolean"
|
|
(x: true == x || false == x) (fold lib.or false);
|
|
|
|
mergeListOption = mergeTypedOption "list" isList concatLists;
|
|
|
|
mergeStringOption = mergeTypedOption "string"
|
|
(x: if builtins ? isString then builtins.isString x else x + "")
|
|
lib.concatStrings;
|
|
|
|
mergeOneOption = list:
|
|
if list == [] then abort "This case should never happen."
|
|
else if tail list != [] then throw "Multiple definitions. Only one is allowed for this option."
|
|
else head list;
|
|
|
|
|
|
# Handle the traversal of option sets. All sets inside 'opts' are zipped
|
|
# and options declaration and definition are separated. If no option are
|
|
# declared at a specific depth, then the function recurse into the values.
|
|
# Other cases are handled by the optionHandler which contains two
|
|
# functions that are used to defined your goal.
|
|
# - export is a function which takes two arguments which are the option
|
|
# and the list of values.
|
|
# - notHandle is a function which takes the list of values are not handle
|
|
# by this function.
|
|
handleOptionSets = optionHandler@{export, notHandle, ...}: path: opts:
|
|
if all isAttrs opts then
|
|
lib.zip (attr: opts:
|
|
let
|
|
recurseInto = name: attrs:
|
|
handleOptionSets optionHandler name attrs;
|
|
|
|
# Compute the path to reach the attribute.
|
|
name = if path == "" then attr else path + "." + attr;
|
|
|
|
# Divide the definitions of the attribute "attr" between
|
|
# declaration (isOption) and definitions (!isOption).
|
|
test = partition isOption opts;
|
|
decls = test.right; defs = test.wrong;
|
|
|
|
# Make the option declaration more user-friendly by adding default
|
|
# settings and some verifications based on the declaration content
|
|
# (like type correctness).
|
|
opt = addOptionMakeUp
|
|
{ inherit name recurseInto; }
|
|
(mergeOptionDecls decls);
|
|
|
|
# Return the list of option sets.
|
|
optAttrs = map delayProperties defs;
|
|
|
|
# return the list of option values.
|
|
# Remove undefined values that are coming from evalIf.
|
|
optValues = evalProperties defs;
|
|
in
|
|
if decls == [] then recurseInto name optAttrs
|
|
else lib.addErrorContext "while evaluating the option ${name}:" (
|
|
export opt optValues
|
|
)
|
|
) opts
|
|
else lib.addErrorContext "while evaluating ${path}:" (notHandle opts);
|
|
|
|
# Merge option sets and produce a set of values which is the merging of
|
|
# all options declare and defined. If no values are defined for an
|
|
# option, then the default value is used otherwise it use the merge
|
|
# function of each option to get the result.
|
|
mergeOptionSets =
|
|
handleOptionSets {
|
|
export = opt: values:
|
|
opt.apply (
|
|
if values == [] then
|
|
if opt ? default then opt.default
|
|
else throw "Not defined."
|
|
else opt.merge values
|
|
);
|
|
notHandle = opts: throw "Used without option declaration.";
|
|
};
|
|
|
|
# Keep all option declarations.
|
|
filterOptionSets =
|
|
handleOptionSets {
|
|
export = opt: values: opt;
|
|
notHandle = opts: {};
|
|
};
|
|
|
|
|
|
# Unfortunately this can also be a string.
|
|
isPath = x: !(
|
|
builtins.isFunction x
|
|
|| builtins.isAttrs x
|
|
|| builtins.isInt x
|
|
|| builtins.isBool x
|
|
|| builtins.isList x
|
|
);
|
|
|
|
applyIfFunction = f: arg:
|
|
if builtins.isFunction f then
|
|
f arg
|
|
else
|
|
f;
|
|
|
|
moduleClosure = initModules: args:
|
|
let
|
|
moduleImport = path:
|
|
(applyIfFunction (import path) args) // {
|
|
# used by generic closure to avoid duplicated imports.
|
|
key = path;
|
|
};
|
|
in
|
|
builtins.genericClosure {
|
|
startSet = map moduleImport initModules;
|
|
operator = m:
|
|
map moduleImport (attrByPath ["imports"] [] m);
|
|
};
|
|
|
|
selectDeclsAndDefs = modules:
|
|
lib.concatMap (m:
|
|
attrByPath ["options"] [] m
|
|
++ attrByPath ["config"] [] m
|
|
) modules;
|
|
|
|
fixMergeFun = merge: optFun:
|
|
lib.fix (config:
|
|
merge (
|
|
# Delay top-level properties like mkIf
|
|
map delayProperties (
|
|
# generate the list of option sets.
|
|
optFun config
|
|
)
|
|
)
|
|
);
|
|
|
|
fixMergeModules = merge: initModules: {...}@args:
|
|
fixMergeFun (config:
|
|
selectDeclsAndDefs (
|
|
moduleClosure initModules (args // { inherit config; })
|
|
)
|
|
);
|
|
|
|
fixModulesConfig = initModules: {...}@args:
|
|
fixMergeModules (mergeOptionSets "") initModules args;
|
|
|
|
fixOptionsConfig = initModules: {...}@args:
|
|
fixMergeModules (filterOptionSets "") initModules args;
|
|
|
|
|
|
# Evaluate a list of option sets that would be merged with the
|
|
# function "merge" which expects two arguments. The attribute named
|
|
# "require" is used to imports option declarations and bindings.
|
|
#
|
|
# * cfg[0-9]: configuration
|
|
# * cfgSet[0-9]: configuration set
|
|
#
|
|
# merge: the function used to merge options sets.
|
|
# pkgs: is the set of packages available. (nixpkgs)
|
|
# opts: list of option sets or option set functions.
|
|
# config: result of this evaluation.
|
|
fixOptionSetsFun = merge: pkgs: opts: config:
|
|
let
|
|
# remove possible mkIf to access the require attribute.
|
|
noImportConditions = cfgSet0:
|
|
let cfgSet1 = delayProperties cfgSet0; in
|
|
if cfgSet1 ? require then
|
|
cfgSet1 // { require = rmProperties cfgSet1.require; }
|
|
else
|
|
cfgSet1;
|
|
|
|
filenameHandler = cfg:
|
|
if isPath cfg then import cfg
|
|
else cfg;
|
|
|
|
# call configuration "files" with one of the existing convention.
|
|
argumentHandler = cfg:
|
|
let
|
|
# {..}
|
|
cfg0 = cfg;
|
|
# {pkgs, config, ...}: {..}
|
|
cfg1 = cfg { inherit pkgs config merge; };
|
|
# pkgs: config: {..}
|
|
cfg2 = cfg {} {};
|
|
in
|
|
if builtins.isFunction cfg0 then
|
|
if isAttrs cfg1 then cfg1
|
|
else builtins.trace "Use '{pkgs, config, ...}:'." cfg2
|
|
else cfg0;
|
|
|
|
preprocess = cfg0:
|
|
let cfg1 = filenameHandler cfg0;
|
|
cfg2 = argumentHandler cfg1;
|
|
cfg3 = noImportConditions cfg2;
|
|
in cfg3;
|
|
|
|
getRequire = x: toList (attrByPath ["require"] [] (preprocess x));
|
|
getRecursiveRequire = x:
|
|
fold (cfg: l:
|
|
if isPath cfg then
|
|
[ cfg ] ++ l
|
|
else
|
|
[ cfg ] ++ (getRecursiveRequire cfg) ++ l
|
|
) [] (getRequire x);
|
|
|
|
getRequireSets = x: filter (x: ! isPath x) (getRecursiveRequire x);
|
|
getRequirePaths = x: filter isPath (getRecursiveRequire x);
|
|
rmRequire = x: removeAttrs (preprocess x) ["require"];
|
|
|
|
inlineRequiredSets = cfgs:
|
|
fold (cfg: l: [ cfg ] ++ (getRequireSets cfg) ++ l) [] cfgs;
|
|
in
|
|
merge "" (
|
|
map rmRequire (
|
|
inlineRequiredSets ((toList opts) ++ lib.uniqFlatten getRequirePaths [] [] (lib.concatMap getRequirePaths (toList opts)))
|
|
)
|
|
);
|
|
|
|
fixOptionSets = merge: pkgs: opts:
|
|
lib.fix (fixOptionSetsFun merge pkgs opts);
|
|
|
|
|
|
# Generate documentation template from the list of option declaration like
|
|
# the set generated with filterOptionSets.
|
|
optionAttrSetToDocList = ignore: newOptionAttrSetToDocList;
|
|
newOptionAttrSetToDocList = attrs:
|
|
let options = collect isOption attrs; in
|
|
fold (opt: rest:
|
|
let
|
|
docOption = {
|
|
inherit (opt) name;
|
|
description = if opt ? description then opt.description else
|
|
throw "Option ${opt.name}: No description.";
|
|
}
|
|
// (if opt ? example then {inherit(opt) example;} else {})
|
|
// (if opt ? default then {inherit(opt) default;} else {});
|
|
|
|
subOptions =
|
|
if opt ? options then
|
|
newOptionAttrSetToDocList opt.options
|
|
else
|
|
[];
|
|
in
|
|
[ docOption ] ++ subOptions ++ rest
|
|
) [] options;
|
|
|
|
|
|
/* Option Properties */
|
|
# Generalize the problem of delayable properties. Any property can be created
|
|
|
|
|
|
# Tell that nothing is defined. When properties are evaluated, this type
|
|
# is used to remove an entry. Thus if your property evaluation semantic
|
|
# implies that you have to mute the content of an attribute, then your
|
|
# property should produce this value.
|
|
isNotdef = attrs: (typeOf attrs) == "notdef";
|
|
mkNotdef = {_type = "notdef";};
|
|
|
|
# General property type, it has a property attribute and a content
|
|
# attribute. The property attribute refer to an attribute set which
|
|
# contains a _type attribute and a list of functions which are used to
|
|
# evaluate this property. The content attribute is used to stack property
|
|
# on top of each other.
|
|
#
|
|
# The optional functions which may be contained in the property attribute
|
|
# are:
|
|
# - onDelay: run on a copied property.
|
|
# - onGlobalDelay: run on all copied properties.
|
|
# - onEval: run on an evaluated property.
|
|
# - onGlobalEval: run on a list of property stack on top of their values.
|
|
isProperty = attrs: (typeOf attrs) == "property";
|
|
mkProperty = p@{property, content, ...}: p // {
|
|
_type = "property";
|
|
};
|
|
|
|
# Go throw the stack of properties and apply the function `op' on all
|
|
# property and call the function `nul' on the final value which is not a
|
|
# property. The stack is traversed in reversed order. The `op' function
|
|
# should expect a property with a content which have been modified.
|
|
#
|
|
# Warning: The `op' function expects only one argument in order to avoid
|
|
# calls to mkProperties as the argument is already a valid property which
|
|
# contains the result of the folding inside the content attribute.
|
|
foldProperty = op: nul: attrs:
|
|
if isProperty attrs then
|
|
op (attrs // {
|
|
content = foldProperty op nul attrs.content;
|
|
})
|
|
else
|
|
nul attrs;
|
|
|
|
# Simple function which can be used as the `op' argument of the
|
|
# foldProperty function. Properties that you don't want to handle can be
|
|
# ignored with the `id' function. `isSearched' is a function which should
|
|
# check the type of a property and return a boolean value. `thenFun' and
|
|
# `elseFun' are functions which behave as the `op' argument of the
|
|
# foldProperty function.
|
|
foldFilter = isSearched: thenFun: elseFun: attrs:
|
|
if isSearched attrs.property then
|
|
thenFun attrs
|
|
else
|
|
elseFun attrs;
|
|
|
|
|
|
# Move properties from the current attribute set to the attribute
|
|
# contained in this attribute set. This trigger property handlers called
|
|
# `onDelay' and `onGlobalDelay'.
|
|
delayProperties = attrs:
|
|
let cleanAttrs = rmProperties attrs; in
|
|
if isProperty attrs then
|
|
lib.mapAttrs (a: v:
|
|
lib.addErrorContext "while moving properties on the attribute `${a}'." (
|
|
triggerPropertiesGlobalDelay a (
|
|
triggerPropertiesDelay a (
|
|
copyProperties attrs v
|
|
)))) cleanAttrs
|
|
else
|
|
attrs;
|
|
|
|
# Call onDelay functions.
|
|
triggerPropertiesDelay = name: attrs:
|
|
let
|
|
callOnDelay = p@{property, ...}:
|
|
lib.addErrorContext "while calling a onDelay function." (
|
|
if property ? onDelay then
|
|
property.onDelay name p
|
|
else
|
|
p
|
|
);
|
|
in
|
|
foldProperty callOnDelay id attrs;
|
|
|
|
# Call onGlobalDelay functions.
|
|
triggerPropertiesGlobalDelay = name: attrs:
|
|
let
|
|
globalDelayFuns = uniqListExt {
|
|
getter = property: property._type;
|
|
inputList = foldProperty (p@{property, content, ...}:
|
|
if property ? onGlobalDelay then
|
|
[ property ] ++ content
|
|
else
|
|
content
|
|
) (a: []) attrs;
|
|
};
|
|
|
|
callOnGlobalDelay = property: content:
|
|
lib.addErrorContext "while calling a onGlobalDelay function." (
|
|
property.onGlobalDelay name content
|
|
);
|
|
in
|
|
fold callOnGlobalDelay attrs globalDelayFuns;
|
|
|
|
# Expect a list of values which may have properties and return the same
|
|
# list of values where all properties have been evaluated and where all
|
|
# ignored values are removed. This trigger property handlers called
|
|
# `onEval' and `onGlobalEval'.
|
|
evalProperties = valList:
|
|
if valList != [] then
|
|
filter (x: !isNotdef x) (
|
|
lib.addErrorContext "while evaluating properties an attribute." (
|
|
triggerPropertiesGlobalEval (
|
|
map triggerPropertiesEval valList
|
|
)))
|
|
else
|
|
valList;
|
|
|
|
# Call onEval function
|
|
triggerPropertiesEval = val:
|
|
foldProperty (p@{property, ...}:
|
|
lib.addErrorContext "while calling a onEval function." (
|
|
if property ? onEval then
|
|
property.onEval p
|
|
else
|
|
p
|
|
)
|
|
) id val;
|
|
|
|
# Call onGlobalEval function
|
|
triggerPropertiesGlobalEval = valList:
|
|
let
|
|
globalEvalFuns = uniqListExt {
|
|
getter = property: property._type;
|
|
inputList =
|
|
fold (attrs: list:
|
|
foldProperty (p@{property, content, ...}:
|
|
if property ? onGlobalEval then
|
|
[ property ] ++ content
|
|
else
|
|
content
|
|
) (a: list) attrs
|
|
) [] valList;
|
|
};
|
|
|
|
callOnGlobalEval = property: valList:
|
|
lib.addErrorContext "while calling a onGlobalEval function." (
|
|
property.onGlobalEval valList
|
|
);
|
|
in
|
|
fold callOnGlobalEval valList globalEvalFuns;
|
|
|
|
# Remove all properties on top of a value and return the value.
|
|
rmProperties =
|
|
foldProperty (p@{content, ...}: content) id;
|
|
|
|
# Copy properties defined on a value on another value.
|
|
copyProperties = attrs: newAttrs:
|
|
foldProperty id (x: newAttrs) attrs;
|
|
|
|
/* If. ThenElse. Always. */
|
|
|
|
# create "if" statement that can be delayed on sets until a "then-else" or
|
|
# "always" set is reached. When an always set is reached the condition
|
|
# is ignore.
|
|
|
|
# Create a "If" property which only contains a condition.
|
|
isIf = attrs: (typeOf attrs) == "if";
|
|
mkIf = condition: content: mkProperty {
|
|
property = {
|
|
_type = "if";
|
|
onGlobalDelay = onIfGlobalDelay;
|
|
onEval = onIfEval;
|
|
inherit condition;
|
|
};
|
|
inherit content;
|
|
};
|
|
|
|
# Create a "ThenElse" property which contains choices which can choosed by
|
|
# the evaluation of an "If" statement.
|
|
isThenElse = attrs: (typeOf attrs) == "then-else";
|
|
mkThenElse = attrs:
|
|
assert attrs ? thenPart && attrs ? elsePart;
|
|
mkProperty {
|
|
property = {
|
|
_type = "then-else";
|
|
onEval = val: throw "Missing mkIf statement.";
|
|
inherit (attrs) thenPart elsePart;
|
|
};
|
|
content = mkNotdef;
|
|
};
|
|
|
|
# Create an "Always" property remove ignore all "If" statement.
|
|
isAlways = attrs: (typeOf attrs) == "always";
|
|
mkAlways = value:
|
|
mkProperty {
|
|
property = {
|
|
_type = "always";
|
|
onEval = p@{content, ...}: content;
|
|
inherit value;
|
|
};
|
|
content = mkNotdef;
|
|
};
|
|
|
|
# Remove all "If" statement defined on a value.
|
|
rmIf = foldProperty (
|
|
foldFilter isIf
|
|
({content, ...}: content)
|
|
id
|
|
) id;
|
|
|
|
# Evaluate the "If" statements when either "ThenElse" or "Always"
|
|
# statement is encounter. Otherwise it remove multiple If statement and
|
|
# replace them by one "If" staement where the condition is the list of all
|
|
# conditions joined with a "and" operation.
|
|
onIfGlobalDelay = name: content:
|
|
let
|
|
# extract if statements and non-if statements and repectively put them
|
|
# in the attribute list and attrs.
|
|
ifProps =
|
|
foldProperty
|
|
(foldFilter (p: isIf p || isThenElse p || isAlways p)
|
|
# then, push the codition inside the list list
|
|
(p@{property, content, ...}:
|
|
{ inherit (content) attrs;
|
|
list = [property] ++ content.list;
|
|
}
|
|
)
|
|
# otherwise, add the propertie.
|
|
(p@{property, content, ...}:
|
|
{ inherit (content) list;
|
|
attrs = p // { content = content.attrs; };
|
|
}
|
|
)
|
|
)
|
|
(attrs: { list = []; inherit attrs; })
|
|
content;
|
|
|
|
# compute the list of if statements.
|
|
evalIf = content: condition: list:
|
|
if list == [] then
|
|
mkIf condition content
|
|
else
|
|
let p = head list; in
|
|
|
|
# evaluate the condition.
|
|
if isThenElse p then
|
|
if condition then
|
|
copyProperties content p.thenPart
|
|
else
|
|
copyProperties content p.elsePart
|
|
# ignore the condition.
|
|
else if isAlways p then
|
|
copyProperties content p.value
|
|
# otherwise (isIf)
|
|
else
|
|
evalIf content (condition && p.condition) (tail list);
|
|
in
|
|
evalIf ifProps.attrs true ifProps.list;
|
|
|
|
# Evaluate the condition of the "If" statement to either get the value or
|
|
# to ignore the value.
|
|
onIfEval = p@{property, content, ...}:
|
|
if property.condition then
|
|
content
|
|
else
|
|
mkNotdef;
|
|
|
|
/* mkOverride */
|
|
|
|
# Create an "Override" statement which allow the user to define
|
|
# prioprities between values. The default priority is 100 and the lowest
|
|
# priorities are kept. The template argument must reproduce the same
|
|
# attribute set hierachy to override leaves of the hierarchy.
|
|
isOverride = attrs: (typeOf attrs) == "override";
|
|
mkOverride = priority: template: content: mkProperty {
|
|
property = {
|
|
_type = "override";
|
|
onDelay = onOverrideDelay;
|
|
onGlobalEval = onOverrideGlobalEval;
|
|
inherit priority template;
|
|
};
|
|
inherit content;
|
|
};
|
|
|
|
# Make the template traversal in function of the property traversal. If
|
|
# the template define a non-empty attribute set, then the property is
|
|
# copied only on all mentionned attributes inside the template.
|
|
# Otherwise, the property is kept on all sub-attribute definitions.
|
|
onOverrideDelay = name: p@{property, content, ...}:
|
|
let inherit (property) template; in
|
|
if isAttrs template && template != {} then
|
|
if hasAttr name template then
|
|
p // {
|
|
property = p.property // {
|
|
template = builtins.getAttr name template;
|
|
};
|
|
}
|
|
# Do not override the attribute \name\
|
|
else
|
|
content
|
|
# Override values defined inside the attribute \name\.
|
|
else
|
|
p;
|
|
|
|
# Ignore all values which have a higher value of the priority number.
|
|
onOverrideGlobalEval = valList:
|
|
let
|
|
defaultPrio = 100;
|
|
|
|
inherit (builtins) lessThan;
|
|
|
|
getPrioVal =
|
|
foldProperty
|
|
(foldFilter isOverride
|
|
(p@{property, content, ...}:
|
|
if lessThan content.priority property.priority then
|
|
content
|
|
else
|
|
content // {
|
|
inherit (property) priority;
|
|
}
|
|
)
|
|
(p@{property, content, ...}:
|
|
content // {
|
|
value = p // { content = content.value; };
|
|
}
|
|
)
|
|
) (value: { priority = defaultPrio; inherit value; });
|
|
|
|
prioValList = map getPrioVal valList;
|
|
|
|
higherPrio = fold (x: y:
|
|
if lessThan x.priority y then
|
|
x.priority
|
|
else
|
|
y
|
|
) defaultPrio prioValList;
|
|
in
|
|
map (x:
|
|
if x.priority == higherPrio then
|
|
x.value
|
|
else
|
|
mkNotdef
|
|
) prioValList;
|
|
|
|
}
|