nixpkgs/pkgs/lib/default-unstable.nix
Marc Weber ddb31307de fix: adding defaults
svn path=/nixpkgs/trunk/; revision=9283
2007-09-10 06:05:38 +00:00

428 lines
16 KiB
Nix

# Utility functions.
let
inherit (builtins)
head tail isList stringLength substring lessThan sub listToAttrs;
in
rec {
# "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) "";
# 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));
concatStringsSep = separator: list:
concatStrings (intersperse separator list);
# 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: I'd rename this to getAttrRec or something like that .. (has the same name as builtin.getAttr) - Marc Weber
getAttr = attrPath: default: e:
let {
attr = head attrPath;
body =
if attrPath == [] then e
else if builtins ? hasAttr && builtins.hasAttr attr e
then getAttr (tail attrPath) default (builtins.getAttr attr e)
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, or returns the default value.
findSingle = pred: default: list:
let found = filter pred list;
in if found == [] then default
else if tail found != [] then
abort "Multiple elements match predicate in findSingle."
else head found;
# 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);
# 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;
# 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" && (name == ".svn" || name == "CVS")) ||
# Filter out backup files.
(hasSuffix "~" name)
);
in src: builtins.filterSource filter src;
# 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 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);};
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;
# calls a function (f attr value ) for each record item. returns a list
mapRecordFlatten = f : r : map (attr: f attr (__getAttr attr r) ) (__attrNames r);
# to be used with listToAttrs (_a_ttribute _v_alue)
av = attr : value : { inherit attr value; };
# attribute set containing one attribute
avs = attr : value : listToAttrs [ (av attr value) ];
# adds / replaces an attribute of an attribute set
setAttr = set : attr : v : set // (avs attr v);
id = x : x;
# 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);
# iterates over a list of attributes collecting the attribute attr if it exists
catAttrs = attr : l : fold ( s : l : if (__hasAttr attr s) then [(__getAttr attr s)] ++ l else l) [] l;
mergeAttrs = fold ( x : y : x // y) {};
flattenAttrs = set : map ( attr : __getAttr attr set) (__attrNames set);
mapIf = cond : f : fold ( x : l : if (cond x) then [(f x)] ++ l else l) [];
# Marc 2nd proposal: (not everything has been tested in detail yet..)
# calls chooseOptionsByFlags2 with some preprocessing
# chooseOptionsByFlags2 returns an attribute set meant to be used to create new derivaitons.
# see mkDerivationByConfigruation 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 : av o ( { buildInputs = o; pass = avs o (__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 = (__getAttr flag flagConfig);
implied = flatten ( getAttr ["implies"] [] fDesc );
blocked = flatten ( getAttr ["blocks"] [] fDesc );
# add this flag
s2 = s // { result = ( setAttr s.result flag (__getAttr flag flagConfig) );
blockedFlagsBy = s.blockedFlagsBy
// listToAttrs (map (b: av 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 ) ) );
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 (__getAttr attr args) )
(flatten (catAttrs "buildInputs" flatOptions));
configureFlags = optsConcatStrs " " "cfgOption";
#flags = listToAttrs (map ( flag: av flag (__hasAttr flag options) ) (__attrNames flagConfig) );
flags_prefixed = listToAttrs (map ( flag: av ("flag_set_"+flag) (__hasAttr flag options) ) (__attrNames flagConfig) );
pass = mergeAttrs (flatten (collectAttrs "pass") );
} # now add additional phase actions (see examples)
// listToAttrs ( map ( x : av x (optsConcatStrs "\n" x) ) collectExtraPhaseActions ) );
}
/*
# ###########################################################################
# 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 =
# * 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 : mkDerivationByConfigruation ( {
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" ];
};
*/