let lib = import ./default.nix; in
with import ./lists.nix;
with import ./attrsets.nix;
with import ./strings.nix;
rec {
# 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; } );
# returns f x // { passthru.fun = y : f (merge x y); } while preserving other passthru names.
# example: let ex = applyAndFun (x : removeAttrs x ["fixed"]) (mergeOrApply mergeAttr) {name = 6;};
# usage1 = ex.passthru.fun { name = 7; }; # result: { name = 7;}
# usage2 = ex.passthru.fun (a: a // {name = __add a.name 1; }); # result: { a = 7; }
# fix usage:
# usage3a = ex.passthru.fun (a: a // {name2 = a.fixed.toBePassed; }); # usage3a will fail because toBePassed is not yet given
# usage3b usage3a.passthru.fun { toBePassed = "foo";}; # result { name = 7; name2 = "foo"; toBePassed = "foo"; fixed = <this attrs>; }
applyAndFun = f : merge : x : assert (__isAttrs x || __isFunction x);
let takeFix = if (__isFunction x) then x else (attr: merge attr x); in
setAttrMerge "passthru" {} (lib.fix (fixed : f (takeFix {inherit fixed;})))
( y : y //
{
fun = z : applyAndFun f merge (fixed: merge (takeFix fixed) z);
funMerge = z : applyAndFun f merge (fixed: let e = takeFix fixed; in merge e (merge e z));
} );
mergeOrApply = merge : x : y : if (__isFunction y) then y x else merge x y;
# 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 [];
# shortcut for getAttr ["name"] default attrs
maybeAttr = name: default: attrs:
if (__hasAttr name attrs) then (__getAttr name attrs) else default;
# 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 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 (elem name (getAttr ["flags"] [] attrSet)) then true else
getAttr [name] false attrSet ;
# 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 lib.and true
(map (x: let name = (head x) ; in
((checkFlag attrSet name) ->
(fold lib.and true
(map (y: let val=(getValue attrSet argList y); in
(val!=null) && (val!=false))
(tail x))))) condList)) ;
uniqList = {inputList, outputList ? []}:
if (inputList == []) then outputList else
let x=head inputList;
newOutputList = outputList ++
(if elem x outputList 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));
# flatten a list of elements by following the properties of the elements.
# next : return the list of following elements.
# seen : lists of elements already visited.
# default: result if 'x' is empty.
# x : list of values that have to be processed.
uniqFlatten = next: seen: default: x:
if x == []
then default
else
let h = head x; t = tail x; n = next h; in
if elem h seen
then uniqFlatten next seen default t
else uniqFlatten next (seen ++ [h]) (default ++ [h]) (n ++ t)
;
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);});
# calls a function (f attr value ) for each record item. returns a list
# should be renamed to mapAttrsFlatten
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;
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
# ! depreceated, use mergeAttrByFunc instead
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);
# example usage:
# mergeAttrByFunc {
# inherit mergeAttrBy; # defined below
# buildInputs = [ a b ];
# } {
# buildInputs = [ c d ];
# };
# will result in
# { mergeAttrsBy = [...]; buildInputs = [ a b c d ]; }
# is used by prepareDerivationArgs and can be used when composing using
# foldArgs, composedArgsAndFun or applyAndFun. Example: composableDerivation in all-packages.nix
mergeAttrByFunc = x : y :
let
mergeAttrBy2 = { mergeAttrBy=lib.mergeAttrs; }
// (maybeAttr "mergeAttrBy" {} x)
// (maybeAttr "mergeAttrBy" {} y); in
fold lib.mergeAttrs {} [
x y
(mapAttrs ( a : v : # merge special names using given functions
if (__hasAttr a x)
then if (__hasAttr a y)
then v (__getAttr a x) (__getAttr a y) # both have attr, use merge func
else (__getAttr a x) # only x has attr
else (__getAttr a y) # only y has attr)
) (removeAttrs mergeAttrBy2
# don't merge attrs which are neither in x nor y
(filter (a : (! __hasAttr a x) && (! __hasAttr a y) )
(__attrNames mergeAttrBy2))
)
)
];
mergeAttrsByFuncDefaults = foldl mergeAttrByFunc { inherit mergeAttrBy; };
# sane defaults (same name as attr name so that inherit can be used)
mergeAttrBy = # { buildInputs = concatList; [...]; passthru = mergeAttr; [..]; }
listToAttrs (map (n : nv n lib.concat) [ "buildInputs" "propagatedBuildInputs" "configureFlags" "prePhases" "postAll" ])
// listToAttrs (map (n : nv n lib.mergeAttrs) [ "passthru" "meta" "cfg" "flags" ]);
# 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 );
# prepareDerivationArgs tries to make writing configurable derivations easier
# example:
# prepareDerivationArgs {
# mergeAttrBy = {
# myScript = x : y : x ++ "\n" ++ y;
# };
# cfg = {
# readlineSupport = true;
# };
# flags = {
# readline = {
# set = {
# configureFlags = [ "--with-compiler=${compiler}" ];
# buildInputs = [ compiler ];
# pass = { inherit compiler; READLINE=1; };
# assertion = compiler.dllSupport;
# myScript = "foo";
# };
# unset = { configureFlags = ["--without-compiler"]; };
# };
# };
# src = ...
# buildPhase = '' ... '';
# name = ...
# myScript = "bar";
# };
# if you don't have need for unset you can omit the surrounding set = { .. } attr
# all attrs except flags cfg and mergeAttrBy will be merged with the
# additional data from flags depending on config settings
# It's used in composableDerivation in all-packages.nix. It's also used
# heavily in the new python and libs implementation
#
# should we check for misspelled cfg options?
prepareDerivationArgs = args:
let args2 = { cfg = {}; flags = {}; } // args;
flagName = name : "${name}Support";
cfgWithDefaults = (listToAttrs (map (n : nv (flagName n) false) (attrNames args2.flags)))
// args2.cfg;
opts = flattenAttrs (mapAttrs (a : v :
let v2 = if (v ? set || v ? unset) then v else { set = v; };
n = if (__getAttr (flagName a) cfgWithDefaults) then "set" else "unset";
attr = maybeAttr n {} v2; in
if (maybeAttr "assertion" true attr)
then attr
else throw "assertion of flag ${a} of derivation ${args.name} failed"
) args2.flags );
in removeAttrs
(mergeAttrsByFuncDefaults ([args] ++ opts ++ [{ passthru = cfgWithDefaults; }]))
["flags" "cfg" "mergeAttrBy" "fixed" ]; # fixed may be passed as fix argument or such
}