nixpkgs/pkgs/lib/default.nix
Marc Weber 1f69d4d1eb enhancing whatis trace function
svn path=/nixpkgs/trunk/; revision=13541
2008-12-02 12:26:12 +00:00

925 lines
35 KiB
Nix

# Utility functions.
let
inherit (builtins)
head tail isList stringLength substring lessThan sub
listToAttrs attrNames hasAttr;
in
rec {
listOfListsToAttrs = ll : builtins.listToAttrs (map (l : { name = (head l); value = (head (tail l)); }) ll);
# Identity function.
id = x: x;
# accumulates / merges all attr sets until null is fed.
# example: sumArgs id { a = 'a'; x = 'x'; } { y = 'y'; x = 'X'; } null
# result : { a = 'a'; x = 'X'; y = 'Y'; }
innerSumArgs = f : x : y : (if y == null then (f x)
else (innerSumArgs f (x // y)));
sumArgs = f : innerSumArgs f {};
# Advanced sumArgs version. Hm, twice as slow, I'm afraid.
# composedArgs id (x:x//{a="b";}) (x:x//{b=x.a + "c";}) null;
# {a="b" ; b="bc";};
innerComposedArgs = f : x : y : (if y==null then (f x)
else (if (builtins.isAttrs y) then
(innerComposedArgs f (x//y))
else (innerComposedArgs f (y x))));
composedArgs = f: innerComposedArgs f {};
defaultMergeArg = x : y: if builtins.isAttrs y then
y
else
(y x);
defaultMerge = x: y: x // (defaultMergeArg x y);
sumTwoArgs = f: x: y:
f (defaultMerge x y);
foldArgs = merger: f: init: x:
let arg=(merger init (defaultMergeArg init x)); in
# now add the function with composed args already applied to the final attrs
setAttrMerge "passthru" {} (f arg) ( x : x // { function = foldArgs merger f arg; } );
# rec { # an example of how composedArgsAndFun can be used
# a = composedArgsAndFun (x : x) { a = ["2"]; meta = { d = "bar";}; };
# # meta.d will be lost ! It's your task to preserve it (eg using a merge function)
# b = a.passthru.function { a = [ "3" ]; meta = { d2 = "bar2";}; };
# # instead of passing/ overriding values you can use a merge function:
# c = b.passthru.function ( x: { a = x.a ++ ["4"]; }); # consider using (maybeAttr "a" [] x)
# }
# result:
# {
# a = { a = ["2"]; meta = { d = "bar"; }; passthru = { function = .. }; };
# b = { a = ["3"]; meta = { d2 = "bar2"; }; passthru = { function = .. }; };
# c = { a = ["3" "4"]; meta = { d2 = "bar2"; }; passthru = { function = .. }; };
# # c2 is equal to c
# }
composedArgsAndFun = f: foldArgs defaultMerge f {};
# example a = pairMap (x : y : x + y) ["a" "b" "c" "d"];
# result: ["ab" "cd"]
innerPairMap = acc: f: l:
if l == [] then acc else
innerPairMap (acc ++ [(f (head l)(head (tail l)))])
f (tail (tail l));
pairMap = innerPairMap [];
# "Fold" a binary function `op' between successive elements of
# `list' with `nul' as the starting value, i.e., `fold op nul [x_1
# x_2 ... x_n] == op x_1 (op x_2 ... (op x_n nul))'. (This is
# Haskell's foldr).
fold = op: nul: list:
if list == []
then nul
else op (head list) (fold op nul (tail list));
# Concatenate a list of lists.
concatLists =
fold (x: y: x ++ y) [];
# Concatenate a list of strings.
concatStrings =
fold (x: y: x + y) "";
# Map and concatenate the result.
concatMap = f: list: concatLists (map f list);
concatMapStrings = f: list: concatStrings (map f list);
# Place an element between each element of a list, e.g.,
# `intersperse "," ["a" "b" "c"]' returns ["a" "," "b" "," "c"].
intersperse = separator: list:
if list == [] || tail list == []
then list
else [(head list) separator]
++ (intersperse separator (tail list));
toList = x : if (__isList x) then x else [x];
concatStringsSep = separator: list:
concatStrings (intersperse separator list);
makeLibraryPath = paths: concatStringsSep ":" (map (path: path + "/lib") paths);
# Flatten the argument into a single list; that is, nested lists are
# spliced into the top-level lists. E.g., `flatten [1 [2 [3] 4] 5]
# == [1 2 3 4 5]' and `flatten 1 == [1]'.
flatten = x:
if isList x
then fold (x: y: (flatten x) ++ y) [] x
else [x];
# Return an attribute from nested attribute sets. For instance ["x"
# "y"] applied to some set e returns e.x.y, if it exists. The
# default value is returned otherwise.
# comment: there is also builtins.getAttr ? (is there a better name for this function?)
getAttr = attrPath: default: e:
let attr = head attrPath;
in
if attrPath == [] then e
else if builtins ? hasAttr && builtins.hasAttr attr e
then getAttr (tail attrPath) default (builtins.getAttr attr e)
else default;
# shortcut for getAttr ["name"] default attrs
maybeAttr = name: default: attrs:
if (__hasAttr name attrs) then (__getAttr name attrs) else default;
# Filter a list using a predicate; that is, return a list containing
# every element from `list' for which `pred' returns true.
filter = pred: list:
fold (x: y: if pred x then [x] ++ y else y) [] list;
# Return true if `list' has an element `x':
elem = x: list: fold (a: bs: x == a || bs) false list;
# Find the sole element in the list matching the specified
# predicate, returns `default' if no such element exists, or
# `multiple' if there are multiple matching elements.
findSingle = pred: default: multiple: list:
let found = filter pred list;
in if found == [] then default
else if tail found != [] then multiple
else head found;
# Return true iff function `pred' returns true for at least element
# of `list'.
any = pred: list:
if list == [] then false
else if pred (head list) then true
else any pred (tail list);
# Return true iff function `pred' returns true for all elements of
# `list'.
all = pred: list:
if list == [] then true
else if pred (head list) then all pred (tail list)
else false;
# much shorter implementations using map and fold (are lazy as well)
# which ones are better?
# true if all/ at least one element(s) satisfy f
# all = f : l : fold logicalAND true (map f l);
# any = f : l : fold logicalOR false (map f l);
# Return true if each element of a list is equal, false otherwise.
eqLists = xs: ys:
if xs == [] && ys == [] then true
else if xs == [] || ys == [] then false
else head xs == head ys && eqLists (tail xs) (tail ys);
# Workaround, but works in stable Nix now.
eqStrings = a: b: (a+(substring 0 0 b)) == ((substring 0 0 a)+b);
# Determine whether a filename ends in the given suffix.
hasSuffix = ext: fileName:
let lenFileName = stringLength fileName;
lenExt = stringLength ext;
in !(lessThan lenFileName lenExt) &&
substring (sub lenFileName lenExt) lenFileName fileName == ext;
hasSuffixHack = a: b: hasSuffix (a+(substring 0 0 b)) ((substring 0 0 a)+b);
# Bring in a path as a source, filtering out all Subversion and CVS
# directories, as well as backup files (*~).
cleanSource =
let filter = name: type: let baseName = baseNameOf (toString name); in ! (
# Filter out Subversion and CVS directories.
(type == "directory" && (baseName == ".svn" || baseName == "CVS")) ||
# Filter out backup files.
(hasSuffix "~" baseName)
);
in src: builtins.filterSource filter src;
# Get all files ending with the specified suffices from the given
# directory. E.g. `sourceFilesBySuffices ./dir [".xml" ".c"]'.
sourceFilesBySuffices = path: exts:
let filter = name: type:
let base = baseNameOf (toString name);
in type != "directory" && any (ext: hasSuffix ext base) exts;
in builtins.filterSource filter path;
# Return a singleton list or an empty list, depending on a boolean
# value. Useful when building lists with optional elements
# (e.g. `++ optional (system == "i686-linux") flashplayer').
optional = cond: elem: if cond then [elem] else [];
# Return a list or an empty list, dependening on a boolean value.
optionals = cond: elems: if cond then elems else [];
optionalString = cond: string: if cond then string else "";
# Return the second argument if the first one is true or the empty version
# of the second argument.
ifEnable = cond: val:
if cond then val
else if builtins.isList val then []
else if builtins.isAttrs val then {}
# else if builtins.isString val then ""
else if (val == true || val == false) then false
else null;
# Return a list of integers from `first' up to and including `last'.
range = first: last:
if builtins.lessThan last first
then []
else [first] ++ range (builtins.add first 1) last;
# Return true only if there is an attribute and it is true.
checkFlag = attrSet: name:
if (name == "true") then true else
if (name == "false") then false else
if (isInList (getAttr ["flags"] [] attrSet) name) then true else
getAttr [name] false attrSet ;
logicalOR = x: y: x || y;
logicalAND = x: y: x && y;
# Input : attrSet, [ [name default] ... ], name
# Output : its value or default.
getValue = attrSet: argList: name:
( getAttr [name] (if checkFlag attrSet name then true else
if argList == [] then null else
let x = builtins.head argList; in
if (head x) == name then
(head (tail x))
else (getValue attrSet
(tail argList) name)) attrSet );
# Input : attrSet, [[name default] ...], [ [flagname reqs..] ... ]
# Output : are reqs satisfied? It's asserted.
checkReqs = attrSet : argList : condList :
(
fold logicalAND true
(map (x: let name = (head x) ; in
((checkFlag attrSet name) ->
(fold logicalAND true
(map (y: let val=(getValue attrSet argList y); in
(val!=null) && (val!=false))
(tail x))))) condList)) ;
isInList = list: x:
if (list == []) then false else
if (x == (head list)) then true else
isInList (tail list) x;
uniqList = {inputList, outputList ? []}:
if (inputList == []) then outputList else
let x=head inputList;
newOutputList = outputList ++
(if (isInList outputList x) then [] else [x]);
in uniqList {outputList=newOutputList;
inputList = (tail inputList);};
uniqListExt = {inputList, outputList ? [],
getter ? (x : x), compare ? (x: y: x==y)}:
if (inputList == []) then outputList else
let x=head inputList;
isX = y: (compare (getter y) (getter x));
newOutputList = outputList ++
(if any isX outputList then [] else [x]);
in uniqListExt {outputList=newOutputList;
inputList = (tail inputList);
inherit getter compare;
};
condConcat = name: list: checker:
if list == [] then name else
if checker (head list) then
condConcat
(name + (head (tail list)))
(tail (tail list))
checker
else condConcat
name (tail (tail list)) checker;
# Merge sets of attributes and use the function f to merge
# attributes values.
zip = f: sets:
builtins.listToAttrs (map (name: {
inherit name;
value =
f name
(map (__getAttr name)
(filter (__hasAttr name) sets));
}) (concatMap builtins.attrNames sets));
# divide a list in two depending on the evaluation of a predicate.
partition = pred:
fold (h: t:
if pred h
then { right = [h] ++ t.right; wrong = t.wrong; }
else { right = t.right; wrong = [h] ++ t.wrong; }
) { right = []; wrong = []; };
# Take a function and evaluate it with its own returned value.
fix = f:
(rec { result = f result; }).result;
# flatten a list of sets returned by 'f'.
# f : function to evaluate each set.
# attr : name of the attribute which contains more values.
# default: result if 'x' is empty.
# x : list of values that have to be processed.
uniqFlattenAttr = f: attr: default: x:
if x == []
then default
else
let h = f (head x); t = tail x;
v = removeAttrs h [attr]; n = getAttr [attr] [] h;
in
if elem v default
then uniqFlattenAttr f attr default t
else uniqFlattenAttr f attr (default ++ [v]) (toList n ++ t)
;
/* If. ThenElse. Always. */
# create "if" statement that can be dealyed on sets until a "then-else" or
# "always" set is reached. When an always set is reached by
isIf = attrs: (typeOf attrs) == "if";
mkIf = condition: thenelse:
if isIf thenelse then
mkIf (condition && thenelse.condition) thenelse.thenelse
else {
_type = "if";
inherit condition thenelse;
};
isThenElse = attrs: (typeOf attrs) == "then-else";
mkThenElse = attrs:
assert attrs ? thenPart && attrs ? elsePart;
attrs // { _type = "then-else"; };
isAlways = attrs: (typeOf attrs) == "always";
mkAlways = value: { inherit value; _type = "always"; };
pushIf = f: attrs:
if isIf attrs then pushIf f (
let val = attrs.thenelse; in
# evaluate the condition.
if isThenElse val then
if attrs.condition then
val.thenPart
else
val.elsePart
# ignore the condition.
else if isAlways val then
val.value
# otherwise
else
f attrs.condition val)
else
attrs;
# take care otherwise you will have to handle this by hand.
rmIf = pushIf (condition: val: val);
evalIf = pushIf (condition: val:
# guess: empty else part.
ifEnable condition val
);
delayIf = pushIf (condition: val:
# rewrite the condition on sub-attributes.
mapAttrs (name: mkIf condition) val
);
/* Options. */
mkOption = attrs: attrs // {_type = "option";};
typeOf = x: if (__isAttrs x && x ? _type) then x._type else "";
isOption = attrs: (typeOf attrs) == "option";
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 builtins.hasAttr defName opts
then builtins.getAttr defName opts
else defValue.default
else
# `defValue' is an attribute set containing options.
# So recurse.
if builtins.hasAttr defName opts && builtins.isAttrs optValue
then addDefaultOptionValues defValue optValue
else addDefaultOptionValues defValue {};
}
) (builtins.attrNames defs));
mergeDefaultOption = name: list:
if list != [] && tail list == [] then head list
else if all __isFunction list then x: mergeDefaultOption (map (f: f x) list)
else if all __isList list then concatLists list
else if all __isAttrs list then mergeAttrs list
else if all (x: true == x || false == x) list then fold logicalOR false list
else abort "${name}: Cannot merge values.";
mergeTypedOption = typeName: predicate: merge: name: list:
if all predicate list then merge list
else abort "${name}: Expect a ${typeName}.";
mergeEnableOption = mergeTypedOption "boolean"
(x: true == x || false == x) (fold logicalOR false);
mergeListOption = mergeTypedOption "list"
__isList concatLists;
mergeStringOption = mergeTypedOption "string"
(x: if builtins ? isString then builtins.isString x else x + "")
concatStrings;
# Merge sets of options and bindings.
# noOption: function to call if no option is declared.
mergeOptionSets = noOption: path: opts:
if all __isAttrs opts then
zip (attr: opts:
let
name = if path == "" then attr else path + "." + attr;
test = partition isOption opts;
opt = ({ merge = mergeDefaultOption; apply = id; } // head test.right);
in
if test.right == [] then mergeOptionSets noOption name (map delayIf test.wrong)
else if tail test.right != [] then throw "Multiple options for '${name}'."
else if test.wrong == [] then opt.apply opt.default
else opt.apply (opt.merge name (map evalIf test.wrong))
) opts
else noOption path opts;
# Keep all option declarations and add an attribute "name" inside
# each option which contains the path that has to be followed to
# access it.
filterOptionSets = path: opts:
if all __isAttrs opts then
zip (attr: opts:
let
name = if path == "" then attr else path + "." + attr;
test = partition isOption opts;
in
if test.right == [] then filterOptionSets name (map delayIf test.wrong)
else if tail test.right != [] then throw "Multiple options for '${name}'."
else { inherit name; } // (head test.right)
) opts
else {};
# 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.
fixOptionSetsFun = merge: pkgs: opts:
let
# ignore all conditions that are on require attributes.
rmRequireIf = conf:
let conf2 = delayIf conf; in
if conf2 ? require then
conf2 // { require = rmIf conf2.require; }
else
conf2;
# call configuration "files" with one of the existing convention.
optionSet = config: configFun:
if __isFunction configFun then
let result = configFun { inherit pkgs config; }; in
# {pkgs, config, ...}: {..}
if builtins.isAttrs result then result
# pkgs: config: {..}
else configFun pkgs config
# {..}
else configFun;
processConfig = config: configFun:
rmRequireIf (optionSet config configFun);
in
config: merge "" (
uniqFlattenAttr (processConfig config) "require" [] (toList opts)
);
fixOptionSets = merge: pkgs: opts:
fix (fixOptionSetsFun merge pkgs opts);
optionAttrSetToDocList = (l: attrs:
(if (getAttr ["_type"] "" attrs) == "option" then
[({
#inherit (attrs) description;
description = if attrs ? description then attrs.description else
throw ("No description ${toString l} : ${whatis attrs}");
}
//(if attrs ? example then {inherit(attrs) example;} else {} )
//(if attrs ? default then {inherit(attrs) default;} else {} )
//{name = l;}
)]
else (concatLists (map (s: (optionAttrSetToDocList
(l + (if l=="" then "" else ".") + s) (builtins.getAttr s attrs)))
(builtins.attrNames attrs)))));
innerModifySumArgs = f: x: a: b: if b == null then (f a b) // x else
innerModifySumArgs f x (a // b);
modifySumArgs = f: x: innerModifySumArgs f x {};
debugVal = if builtins ? trace then x: (builtins.trace x x) else x: x;
debugXMLVal = if builtins ? trace then x: (builtins.trace (builtins.toXML x) x) else x: x;
# this can help debug your code as well - designed to not produce thousands of lines
traceWhatis = x : __trace (whatis x) x;
traceMarked = str: x: __trace (str + (whatis x)) x;
attrNamesToStr = a : concatStringsSep "; " (map (x : "${x}=") (__attrNames a));
whatis = x :
if (__isAttrs x) then
if (x ? outPath) then "x is a derivation, name ${if x ? name then x.name else "<no name>"}, { ${attrNamesToStr x} }"
else "x is attr set { ${attrNamesToStr x} }"
else if (__isFunction x) then "x is a function"
else if (x == []) then "x is an empty list"
else if (__isList x) then "x is a list, first item is : ${whatis (__head x)}"
else if (x == true) then "x is boolean true"
else if (x == false) then "x is boolean false"
else if (x == null) then "x is null"
else "x is probably a string starting, starting characters: ${__substring 0 50 x}..";
# trace the arguments passed to function and its result
traceCall = n : f : a : let t = n2 : x : traceMarked "${n} ${n2}:" x; in t "result" (f (t "arg 1" a));
traceCall2 = n : f : a : b : let t = n2 : x : traceMarked "${n} ${n2}:" x; in t "result" (f (t "arg 1" a) (t "arg 2" b));
traceCall3 = n : f : a : b : c : let t = n2 : x : traceMarked "${n} ${n2}:" x; in t "result" (f (t "arg 1" a) (t "arg 2" b) (t "arg 3" c));
innerClosePropagation = ready: list: if list == [] then ready else
if (head list) ? propagatedBuildInputs then
innerClosePropagation (ready ++ [(head list)])
((head list).propagatedBuildInputs ++ (tail list)) else
innerClosePropagation (ready ++ [(head list)]) (tail list);
closePropagation = list: (uniqList {inputList = (innerClosePropagation [] list);});
stringToCharacters = s : let l = __stringLength s; in
if (__lessThan l 1) then [""] else [(__substring 0 1 s)] ++ stringToCharacters (__substring 1 (__sub l 1) s);
# should this be implemented as primop ? Yes it should..
escapeShellArg = s :
let escapeChar = x : if ( x == "'" ) then "'\"'\"'" else x;
in "'" + concatStrings (map escapeChar (stringToCharacters s) ) +"'";
defineShList = name : list : "\n${name}=(${concatStringsSep " " (map escapeShellArg list)})\n";
# this as well :-) arg: http://foo/bar/bz.ext returns bz.ext
dropPath = s :
if s == "" then "" else
let takeTillSlash = left : c : s :
if left == 0 then s
else if (__substring left 1 s == "/") then
(__substring (__add left 1) (__sub c 1) s)
else takeTillSlash (__sub left 1) (__add c 1) s; in
takeTillSlash (__sub (__stringLength s) 1) 1 s;
# calls a function (f attr value ) for each record item. returns a list
mapRecordFlatten = f : r : map (attr: f attr (builtins.getAttr attr r) ) (attrNames r);
# maps a function on each attr value
# f = attr : value : ..
mapAttrs = f : r : listToAttrs ( mapRecordFlatten (a : v : nv a ( f a v ) ) r);
# to be used with listToAttrs (_a_ttribute _v_alue)
nv = name : value : { inherit name value; };
# attribute set containing one attribute
nvs = name : value : listToAttrs [ (nv name value) ];
# adds / replaces an attribute of an attribute set
setAttr = set : name : v : set // (nvs name v);
# setAttrMerge (similar to mergeAttrsWithFunc but only merges the values of a particular name)
# setAttrMerge "a" [] { a = [2];} (x : x ++ [3]) -> { a = [2 3]; }
# setAttrMerge "a" [] { } (x : x ++ [3]) -> { a = [ 3]; }
setAttrMerge = name : default : attrs : f :
setAttr attrs name (f (maybeAttr name default attrs));
# iterates over a list of attributes collecting the attribute attr if it exists
catAttrs = attr : l : fold ( s : l : if (hasAttr attr s) then [(builtins.getAttr attr s)] ++ l else l) [] l;
mergeAttrs = fold ( x : y : x // y) {};
attrVals = nameList : attrSet :
map (x: builtins.getAttr x attrSet) nameList;
# Using f = a : b = b the result is similar to //
# merge attributes with custom function handling the case that the attribute
# exists in both sets
mergeAttrsWithFunc = f : set1 : set2 :
fold (n: set : if (__hasAttr n set)
then setAttr set n (f (__getAttr n set) (__getAttr n set2))
else set )
set1 (__attrNames set2);
# merging two attribute set concatenating the values of same attribute names
# eg { a = 7; } { a = [ 2 3 ]; } becomes { a = [ 7 2 3 ]; }
mergeAttrsConcatenateValues = mergeAttrsWithFunc ( a : b : (toList a) ++ (toList b) );
# merges attributes using //, if a name exisits in both attributes
# an error will be triggered unless its listed in mergeLists
# so you can mergeAttrsNoOverride { buildInputs = [a]; } { buildInputs = [a]; } {} to get
# { buildInputs = [a b]; }
# merging buildPhase does'nt really make sense. The cases will be rare where appending /prefixing will fit your needs?
# in these cases the first buildPhase will override the second one
mergeAttrsNoOverride = { mergeLists ? ["buildInputs" "propagatedBuildInputs"],
overrideSnd ? [ "buildPhase" ]
} : attrs1 : attrs2 :
fold (n: set :
setAttr set n ( if (__hasAttr n set)
then # merge
if elem n mergeLists # attribute contains list, merge them by concatenating
then (__getAttr n attrs2) ++ (__getAttr n attrs1)
else if elem n overrideSnd
then __getAttr n attrs1
else throw "error mergeAttrsNoOverride, attribute ${n} given in both attributes - no merge func defined"
else __getAttr n attrs2 # add attribute not existing in attr1
)) attrs1 (__attrNames attrs2);
# returns atribute values as a list
flattenAttrs = set : map ( attr : builtins.getAttr attr set) (attrNames set);
mapIf = cond : f : fold ( x : l : if (cond x) then [(f x)] ++ l else l) [];
# pick attrs subset_attr_names and apply f
subsetmap = f : attrs : subset_attr_names :
listToAttrs (fold ( attr : r : if __hasAttr attr attrs
then r ++ [ ( nv attr ( f (__getAttr attr attrs) ) ) ] else r ) []
subset_attr_names );
# Marc 2nd proposal: (not everything has been tested in detail yet..)
# usage / example
# flagConfig = {
# } // (enableDisableFeature "flagName" "configure_feature" extraAttrs;)
#
# is equal to
# flagConfig = {
# flagName = { cfgOption = "--enable-configure_feature"; } // extraAttrs;
# no_flagName = { cfgOption = "--disable-configure_feature"; };
enableDisableFeature = flagName : configure_feature : extraAttrs :
listToAttrs [ ( nv flagName ({ cfgOption = "--enable-${configure_feature}"; } // extraAttrs ) )
( nv "no_${flagName}" ({ cfgOption = "--disable-${configure_feature}"; } ) )];
# calls chooseOptionsByFlags2 with some preprocessing
# chooseOptionsByFlags2 returns an attribute set meant to be used to create new derivaitons.
# see mkDerivationByConfiguration in all-packages.nix and the examples given below.
# You can just copy paste them into all-packages.nix to test them..
chooseOptionsByFlags = { flagConfig, args, optionals ? [], defaults ? [],
collectExtraPhaseActions ? [] } :
let passedOptionals = filter ( x : hasAttr x args ) optionals; # these are in optionals and in args
# we simply merge in <optional_name> = { buildInputs = <arg.<optional_name>; pass = <arg.optional_name>; }
flagConfigWithOptionals = flagConfig // ( listToAttrs
(map ( o : nv o ( { buildInputs = o; pass = nvs o (builtins.getAttr o args); }
// getAttr [o] {} flagConfig )
)
passedOptionals ) );
in chooseOptionsByFlags2 flagConfigWithOptionals collectExtraPhaseActions args
( (getAttr ["flags"] defaults args) ++ passedOptionals);
chooseOptionsByFlags2 = flagConfig : collectExtraPhaseActions : args : flags :
let
# helper function
collectFlags = # state : flags :
fold ( flag : s : (
if (hasAttr flag s.result) then s # this state has already been visited
else if (! hasAttr flag flagConfig) then throw "unkown flag `${flag}' specified"
else let fDesc = (builtins.getAttr flag flagConfig);
implied = flatten ( getAttr ["implies"] [] fDesc );
blocked = flatten ( getAttr ["blocks"] [] fDesc );
# add this flag
s2 = s // { result = ( setAttr s.result flag (builtins.getAttr flag flagConfig) );
blockedFlagsBy = s.blockedFlagsBy
// listToAttrs (map (b: nv b flag ) blocked); };
# add implied flags
in collectFlags s2 implied
));
# chosen contains flagConfig but only having those attributes elected by flags
# (or by implies attributes of elected attributes)
options = let stateOpts = collectFlags { blockedFlagsBy = {}; result = {}; }
(flags ++ ( if (hasAttr "mandatory" flagConfig) then ["mandatory"] else [] ));
# these options have not been chosen (neither by flags nor by implies)
unsetOptions = filter ( x : (! hasAttr x stateOpts.result) && (hasAttr ("no_"+x) flagConfig))
( attrNames flagConfig );
# no add the corresponding no_ attributes as well ..
state = collectFlags stateOpts (map ( x : "no_" + x ) unsetOptions);
in # check for blockings:
assert ( all id ( map ( b: if (hasAttr b state.result)
then throw "flag ${b} is blocked by flag ${__getAttr b state.blockedFlagsBy}"
else true )
(attrNames state.blockedFlagsBy) ) );
state.result;
flatOptions = flattenAttrs options;
# helper functions :
collectAttrs = attr : catAttrs attr flatOptions;
optsConcatStrs = delimiter : attrs : concatStrings
( intersperse delimiter (flatten ( collectAttrs attrs ) ) );
ifStringGetArg = x : if (__isAttrs x) then x # ( TODO implement __isString ?)
else nvs x (__getAttr x args);
in assert ( all id ( mapRecordFlatten ( attr : r : if ( all id ( flatten (getAttr ["assertion"] [] r ) ) )
then true else throw "assertion failed flag ${attr}" )
options) );
( rec {
#foldOptions = attr: f : start: fold f start (catAttrs attr flatOptions);
# compared to flags flagsSet does also contain the implied flags.. This makes it easy to write assertions. ( assert args.
inherit options flatOptions collectAttrs optsConcatStrs;
buildInputs = map ( attr: if (! hasAttr attr args) then throw "argument ${attr} is missing!" else (builtins.getAttr attr args) )
(flatten (catAttrs "buildInputs" flatOptions));
propagatedBuildInputs = map ( attr: if (! hasAttr attr args) then throw "argument ${attr} is missing!" else (builtins.getAttr attr args) )
(flatten (catAttrs "propagatedBuildInputs" flatOptions));
configureFlags = optsConcatStrs " " "cfgOption";
#flags = listToAttrs (map ( flag: nv flag (hasAttr flag options) ) (attrNames flagConfig) );
flags_prefixed = listToAttrs (map ( flag: nv ("flag_set_"+flag) (hasAttr flag options) ) (attrNames flagConfig) );
pass = mergeAttrs ( map ifStringGetArg ( flatten (collectAttrs "pass") ) );
} # now add additional phase actions (see examples)
// listToAttrs ( map ( x : nv x (optsConcatStrs "\n" x) ) collectExtraPhaseActions ) );
}
/*
TODO: Perhaps it's better to move this documentation / these tests into some extra packages ..
# ###########################################################################
# configuration tutorial .. examples and tests..
# Copy this into all-packages.nix and try
# The following derviations will all fail..
# But they will print the passed options so that you can get to know
# how these configurations ought to work.
# TODO: There is no nice way to pass an otpion yet.
# I could imagine something like
# flags = [ "flagA" "flagB" { flagC = 4; } ];
# They are named:
# simpleYes, simpleNo,
# defaultsimpleYes, defaultsimpleNo
# optionalssimpleYes, optionalssimpleNo
# bitingsimpleYes can only be ran with -iA blockingBiteMonster
# assertionsimpleNo
# of course you can use -iA and the attribute name as well to select these examples
# dummy build input
whoGetsTheFlagFirst = gnused;
whoGetsTheFlagLast = gnumake;
# simple example demonstrating containing one flag.
# features:
# * configure options are passed automatically
# * buildInputs are collected (they are special, see the setup script)
# * they can be passed by additional name as well using pass = { inherit (args) python }
# ( or short (value not attrs) : pass = "python" )
# * an attribute named the same way as the flag is added indicating
# true/ false (flag has been set/ not set)
# * extra phase dependend commands can be added
# Its easy to add your own stuff using co.collectAttrs or co.optsConcatStrs
# ( perhaps this name will change?)
simpleFlagYesNoF = namePrefix : extraFlagAttrs : mkDerivationByConfiguration ( {
flagConfig = {
flag = { name = namePrefix + "simpleYes";
cfgOption = [ "--Yes" "--you-dont-need-a-list" ];
buildInputs = [ "whoGetsTheFlagFirst" ];
pass = { inherit gnumake; };
extraConfigureCmd = "echo Hello, it worked! ";
blocks = "bitingMonster";
};
no_flag = { name = namePrefix + "simpleNo";
cfgOption = "--no";
implies = ["bitingMonster"];
};
bitingMonster = {
extraConfigureCmd = "echo Ill bite you";
};
gnutar = { cfgOption="--with-gnutar";
# buildInputs and pass will be added automatically if gnutar is added to optionals
};
# can be used to check configure options of dependencies
# eg testFlag = { assertion = [ arg.desktop.flag_set_wmii (! arg.desktop.flag_set_gnome) (! arg.desktops.flag_set_kde ]; }
assertionFlag = { assertion = false; }; # assert is nix language keyword
};
collectExtraPhaseActions = [ "extraConfigureCmd" ];
extraAttrs = co : {
name = ( __head (co.collectAttrs "name") );
unpackPhase = "
echo my name is
echo \$name
echo
echo flag given \\(should be 1 or empty string\\) ?
echo \$flag_set_flag
echo
echo my build inputs are
echo \$buildInputs
echo
echo my configuration flags are
echo \$configureFlags
echo
echo what about gnumake? Did it pass?
echo \$gnumake
echo
echo configurePhase command is
echo $\configurePhase
echo
echo gnutar passed? \\(optional test\\)
echo \$gnutar
echo
echo dying now
echo die_Hopefully_Soon
";
configurePhase = co.extraConfigureCmd;
};
} // extraFlagAttrs );
simpleYes = simpleFlagYesNoF "" {} {
inherit whoGetsTheFlagFirst lib stdenv;
flags = ["flag"];
};
# note the "I'll bite you" because of the implies attribute
simpleNo = simpleFlagYesNoF "" {} {
inherit whoGetsTheFlagFirst lib stdenv;
flags = [];
};
# specifying defaults by adding a default attribute
yesAgainDefault = simpleFlagYesNoF "default" { defaults = [ "flag" ];} {
inherit whoGetsTheFlagFirst lib stdenv;
};
noAgainOverridingDefault = simpleFlagYesNoF "default" { defaults = [ "flag" ];} {
inherit whoGetsTheFlagFirst lib stdenv;
flags = [];
};
# requested by Michael Raskin: activate flag automatically if dependency is passed:
withGnutarOptional = simpleFlagYesNoF "optionals" { optionals = [ "gnutar" ];} {
flags = [ "flag" ]; # I only need to pass this to trigger name optionalssimpleYes
inherit whoGetsTheFlagFirst lib stdenv;
inherit gnutar;
};
withoutGnutarOptional = simpleFlagYesNoF "optionals" { optionals = [ "gnutar" ];} {
inherit whoGetsTheFlagFirst lib stdenv;
};
# blocking example, this shouldn't even start building:
blockingBiteMonster = simpleFlagYesNoF "biting" {} {
inherit whoGetsTheFlagFirst lib stdenv;
flags = [ "flag" "bitingMonster" ];
};
# assertion example this shouldn't even start building:
assertion = simpleFlagYesNoF "assertion" {} {
inherit whoGetsTheFlagFirst lib stdenv;
flags = [ "assertionFlag" ];
};
*/