lib: Use Nix's static scope checking, fix error message, optimize

Nix can perform static scope checking, but whenever code is inside
a `with` expression, the analysis breaks down, because it can't
know statically what's in the attribute set whose attributes were
brought into scope. In those cases, Nix has to assume that
everything works out.

Except it doesnt. Removing `with` from lib/ revealed an undefined
variable in an error message.

If that doesn't convince you that we're better off without `with`,
I can tell you that this PR results in a 3% evaluation performance
improvement because Nix can look up local variables by index.
This adds up with applications like the module system.

Furthermore, removing `with` makes the binding site of each
variable obvious, which helps with comprehension.

lib/debug.nix

@@ -14,9 +14,25 @@
 */
 { lib }:
 let
-  inherit (builtins) trace isAttrs isList isInt
+  inherit (lib)
-          head substring attrNames;
+    isInt
-  inherit (lib) id elem isFunction;
+    attrNames
+    isList
+    isAttrs
+    substring
+    addErrorContext
+    attrValues
+    concatLists
+    concatStringsSep
+    const
+    elem
+    generators
+    head
+    id
+    isDerivation
+    isFunction
+    mapAttrs
+    trace;
 in
 
 rec {
@@ -94,7 +110,7 @@ rec {
        trace: { a = { b = {…}; }; }
        => null
    */
-  traceSeqN = depth: x: y: with lib;
+  traceSeqN = depth: x: y:
     let snip = v: if      isList  v then noQuotes "[…]" v
                   else if isAttrs v then noQuotes "{…}" v
                   else v;
@@ -149,7 +165,7 @@ rec {
   */
   runTests =
     # Tests to run
-    tests: lib.concatLists (lib.attrValues (lib.mapAttrs (name: test:
+    tests: concatLists (attrValues (mapAttrs (name: test:
     let testsToRun = if tests ? tests then tests.tests else [];
     in if (substring 0 4 name == "test" ||  elem name testsToRun)
        && ((testsToRun == []) || elem name tests.tests)
@@ -176,9 +192,9 @@ rec {
           + "and will be removed in the next release. "
           + "Please use more specific concatenation "
           + "for your uses (`lib.concat(Map)StringsSep`)." )
-    (lib.concatStringsSep "; " (map (x: "${x}=") (attrNames a)));
+    (concatStringsSep "; " (map (x: "${x}=") (attrNames a)));
 
-  showVal = with lib;
+  showVal =
     trace ( "Warning: `showVal` is deprecated "
           + "and will be removed in the next release, "
           + "please use `traceSeqN`" )
@@ -226,7 +242,7 @@ rec {
     trace ( "Warning: `addErrorContextToAttrs` is deprecated "
           + "and will be removed in the next release. "
           + "Please use `builtins.addErrorContext` directly." )
-    (lib.mapAttrs (a: v: lib.addErrorContext "while evaluating ${a}" v) attrs);
+    (mapAttrs (a: v: addErrorContext "while evaluating ${a}" v) attrs);
 
   # example: (traceCallXml "myfun" id 3) will output something like
   # calling myfun arg 1: 3 result: 3

lib/default.nix

@@ -9,7 +9,7 @@ let
 
   lib = makeExtensible (self: let
     callLibs = file: import file { lib = self; };
-  in with self; {
+  in {
 
     # often used, or depending on very little
     trivial = callLibs ./trivial.nix;
@@ -54,7 +54,7 @@ let
     filesystem = callLibs ./filesystem.nix;
 
     # back-compat aliases
-    platforms = systems.doubles;
+    platforms = self.systems.doubles;
 
     # linux kernel configuration
     kernel = callLibs ./kernel.nix;
@@ -64,13 +64,13 @@ let
       hasAttr head isAttrs isBool isInt isList isString length
       lessThan listToAttrs pathExists readFile replaceStrings seq
       stringLength sub substring tail;
-    inherit (trivial) id const pipe concat or and bitAnd bitOr bitXor
+    inherit (self.trivial) id const pipe concat or and bitAnd bitOr bitXor
       bitNot boolToString mergeAttrs flip mapNullable inNixShell min max
       importJSON importTOML warn info showWarnings nixpkgsVersion version mod compare
       splitByAndCompare functionArgs setFunctionArgs isFunction toHexString toBaseDigits;
-    inherit (fixedPoints) fix fix' converge extends composeExtensions
+    inherit (self.fixedPoints) fix fix' converge extends composeExtensions
       makeExtensible makeExtensibleWithCustomName;
-    inherit (attrsets) attrByPath hasAttrByPath setAttrByPath
+    inherit (self.attrsets) attrByPath hasAttrByPath setAttrByPath
       getAttrFromPath attrVals attrValues getAttrs catAttrs filterAttrs
       filterAttrsRecursive foldAttrs collect nameValuePair mapAttrs
       mapAttrs' mapAttrsToList mapAttrsRecursive mapAttrsRecursiveCond
@@ -79,13 +79,13 @@ let
       recursiveUpdate matchAttrs overrideExisting getOutput getBin
       getLib getDev getMan chooseDevOutputs zipWithNames zip
       recurseIntoAttrs dontRecurseIntoAttrs;
-    inherit (lists) singleton forEach foldr fold foldl foldl' imap0 imap1
+    inherit (self.lists) singleton forEach foldr fold foldl foldl' imap0 imap1
       concatMap flatten remove findSingle findFirst any all count
       optional optionals toList range partition zipListsWith zipLists
       reverseList listDfs toposort sort naturalSort compareLists take
       drop sublist last init crossLists unique intersectLists
       subtractLists mutuallyExclusive groupBy groupBy';
-    inherit (strings) concatStrings concatMapStrings concatImapStrings
+    inherit (self.strings) concatStrings concatMapStrings concatImapStrings
       intersperse concatStringsSep concatMapStringsSep
       concatImapStringsSep makeSearchPath makeSearchPathOutput
       makeLibraryPath makeBinPath optionalString
@@ -97,19 +97,19 @@ let
       nameFromURL enableFeature enableFeatureAs withFeature
       withFeatureAs fixedWidthString fixedWidthNumber isStorePath
       toInt readPathsFromFile fileContents;
-    inherit (stringsWithDeps) textClosureList textClosureMap
+    inherit (self.stringsWithDeps) textClosureList textClosureMap
       noDepEntry fullDepEntry packEntry stringAfter;
-    inherit (customisation) overrideDerivation makeOverridable
+    inherit (self.customisation) overrideDerivation makeOverridable
       callPackageWith callPackagesWith extendDerivation hydraJob
       makeScope;
-    inherit (meta) addMetaAttrs dontDistribute setName updateName
+    inherit (self.meta) addMetaAttrs dontDistribute setName updateName
       appendToName mapDerivationAttrset setPrio lowPrio lowPrioSet hiPrio
       hiPrioSet;
-    inherit (sources) pathType pathIsDirectory cleanSourceFilter
+    inherit (self.sources) pathType pathIsDirectory cleanSourceFilter
       cleanSource sourceByRegex sourceFilesBySuffices
       commitIdFromGitRepo cleanSourceWith pathHasContext
       canCleanSource pathIsRegularFile pathIsGitRepo;
-    inherit (modules) evalModules unifyModuleSyntax
+    inherit (self.modules) evalModules unifyModuleSyntax
       applyIfFunction mergeModules
       mergeModules' mergeOptionDecls evalOptionValue mergeDefinitions
       pushDownProperties dischargeProperties filterOverrides
@@ -119,21 +119,21 @@ let
       mkAliasAndWrapDefinitions fixMergeModules mkRemovedOptionModule
       mkRenamedOptionModule mkMergedOptionModule mkChangedOptionModule
       mkAliasOptionModule doRename;
-    inherit (options) isOption mkEnableOption mkSinkUndeclaredOptions
+    inherit (self.options) isOption mkEnableOption mkSinkUndeclaredOptions
       mergeDefaultOption mergeOneOption mergeEqualOption getValues
       getFiles optionAttrSetToDocList optionAttrSetToDocList'
       scrubOptionValue literalExample showOption showFiles
       unknownModule mkOption;
-    inherit (types) isType setType defaultTypeMerge defaultFunctor
+    inherit (self.types) isType setType defaultTypeMerge defaultFunctor
       isOptionType mkOptionType;
-    inherit (asserts)
+    inherit (self.asserts)
       assertMsg assertOneOf;
-    inherit (debug) addErrorContextToAttrs traceIf traceVal traceValFn
+    inherit (self.debug) addErrorContextToAttrs traceIf traceVal traceValFn
       traceXMLVal traceXMLValMarked traceSeq traceSeqN traceValSeq
       traceValSeqFn traceValSeqN traceValSeqNFn traceShowVal
       traceShowValMarked showVal traceCall traceCall2 traceCall3
       traceValIfNot runTests testAllTrue traceCallXml attrNamesToStr;
-    inherit (misc) maybeEnv defaultMergeArg defaultMerge foldArgs
+    inherit (self.misc) maybeEnv defaultMergeArg defaultMerge foldArgs
       maybeAttrNullable maybeAttr ifEnable checkFlag getValue
       checkReqs uniqList uniqListExt condConcat lazyGenericClosure
       innerModifySumArgs modifySumArgs innerClosePropagation
@@ -143,7 +143,7 @@ let
       mergeAttrsByFuncDefaultsClean mergeAttrBy
       fakeHash fakeSha256 fakeSha512
       nixType imap;
-    inherit (versions)
+    inherit (self.versions)
       splitVersion;
   });
 in lib

lib/lists.nix

@@ -1,9 +1,9 @@
 # General list operations.
 
 { lib }:
-with lib.trivial;
 let
   inherit (lib.strings) toInt;
+  inherit (lib.trivial) compare min;
 in
 rec {
 

lib/modules.nix

@@ -1,12 +1,55 @@
 { lib }:
 
-with lib.lists;
+let
-with lib.strings;
+  inherit (lib.attrsets)
-with lib.trivial;
+    mapAttrsRecursiveCond
-with lib.attrsets;
+    ;
-with lib.options;
+  inherit (lib.lists)
-with lib.debug;
+    any all concatLists concatMap
-with lib.types;
+    count filter findFirst foldl foldl'
+    head imap1 length optional
+    reverseList sort
+    ;
+  inherit (lib.options)
+    isOption
+    mkOption
+    showDefs
+    showFiles
+    showOption
+    unknownModule
+    ;
+  inherit (lib.attrsets)
+    attrByPath
+    attrNames
+    catAttrs
+    getAttrFromPath
+    mapAttrs
+    mapAttrsToList
+    optionalAttrs
+    recursiveUpdate
+    setAttrByPath
+    toList
+    ;
+  inherit (lib.types)
+    types
+    ;
+  inherit (lib.trivial)
+    flip
+    id
+    isBool
+    isFunction
+    isString
+    min
+    warn
+    ;
+  inherit (lib.strings)
+    optionalString
+    ;
+  inherit (lib)
+    elem
+    isAttrs
+    ;
+in
 
 rec {
 
@@ -616,7 +659,7 @@ rec {
   fixupOptionType = loc: opt:
     let
       options = opt.options or
-        (throw "Option `${showOption loc'}' has type optionSet but has no option attribute, in ${showFiles opt.declarations}.");
+        (throw "Option `${showOption loc}' has type optionSet but has no option attribute, in ${showFiles opt.declarations}.");
       f = tp:
         let optionSetIn = type: (tp.name == type) && (tp.functor.wrapped.name == "optionSet");
         in

lib/options.nix

@@ -1,11 +1,15 @@
 # Nixpkgs/NixOS option handling.
 { lib }:
 
-with lib.trivial;
+let
-with lib.lists;
+  inherit (lib)
-with lib.attrsets;
+    isAttrs isBool isDerivation isFunction isInt isList isString
-with lib.strings;
+    all collect concatMap concatLists elemAt filter foldl' head length mapAttrs optionals optional take
-
+    ;
+  inherit (lib.attrsets) optionalAttrs;
+  inherit (lib.strings) concatMapStrings concatStringsSep;
+  inherit (lib.types) mkOptionType;
+in
 rec {
 
   /* Returns true when the given argument is an option

lib/sources.nix

@@ -1,16 +1,33 @@
 # Functions for copying sources to the Nix store.
 { lib }:
 
+let
+  inherit (builtins)
+    hasContext
+    match
+    readDir
+    readFile
+    storeDir
+    tryEval
+    ;
+  inherit (lib)
+    filter
+    getAttr
+    isString
+    pathExists
+    split
+    ;
+in
 rec {
 
   # Returns the type of a path: regular (for file), symlink, or directory
-  pathType = p: with builtins; getAttr (baseNameOf p) (readDir (dirOf p));
+  pathType = p: getAttr (baseNameOf p) (readDir (dirOf p));
 
   # Returns true if the path exists and is a directory, false otherwise
-  pathIsDirectory = p: if builtins.pathExists p then (pathType p) == "directory" else false;
+  pathIsDirectory = p: if pathExists p then (pathType p) == "directory" else false;
 
   # Returns true if the path exists and is a regular file, false otherwise
-  pathIsRegularFile = p: if builtins.pathExists p then (pathType p) == "regular" else false;
+  pathIsRegularFile = p: if pathExists p then (pathType p) == "regular" else false;
 
   # Bring in a path as a source, filtering out all Subversion and CVS
   # directories, as well as backup files (*~).
@@ -19,8 +36,8 @@ rec {
     (baseName == ".git" || type == "directory" && (baseName == ".svn" || baseName == "CVS" || baseName == ".hg")) ||
     # Filter out editor backup / swap files.
     lib.hasSuffix "~" baseName ||
-    builtins.match "^\\.sw[a-z]$" baseName != null ||
+    match "^\\.sw[a-z]$" baseName != null ||
-    builtins.match "^\\..*\\.sw[a-z]$" baseName != null ||
+    match "^\\..*\\.sw[a-z]$" baseName != null ||
 
     # Filter out generates files.
     lib.hasSuffix ".o" baseName ||
@@ -89,7 +106,7 @@ rec {
     in lib.cleanSourceWith {
       filter = (path: type:
         let relPath = lib.removePrefix (toString origSrc + "/") (toString path);
-        in lib.any (re: builtins.match re relPath != null) regexes);
+        in lib.any (re: match re relPath != null) regexes);
       inherit src;
     };
 
@@ -102,13 +119,12 @@ rec {
       in type == "directory" || lib.any (ext: lib.hasSuffix ext base) exts;
     in cleanSourceWith { inherit filter; src = path; };
 
-  pathIsGitRepo = path: (builtins.tryEval (commitIdFromGitRepo path)).success;
+  pathIsGitRepo = path: (tryEval (commitIdFromGitRepo path)).success;
 
   # Get the commit id of a git repo
   # Example: commitIdFromGitRepo <nixpkgs/.git>
   commitIdFromGitRepo =
     let readCommitFromFile = file: path:
-      with builtins;
         let fileName       = toString path + "/" + file;
             packedRefsName = toString path + "/packed-refs";
             absolutePath   = base: path:
@@ -145,11 +161,11 @@ rec {
            # packed-refs file, so we have to grep through it:
            then
              let fileContent = readFile packedRefsName;
-                 matchRef = builtins.match "([a-z0-9]+) ${file}";
+                 matchRef = match "([a-z0-9]+) ${file}";
-                 isRef = s: builtins.isString s && (matchRef s) != null;
+                 isRef = s: isString s && (matchRef s) != null;
                  # there is a bug in libstdc++ leading to stackoverflow for long strings:
                  # https://github.com/NixOS/nix/issues/2147#issuecomment-659868795
-                 refs = builtins.filter isRef (builtins.split "\n" fileContent);
+                 refs = filter isRef (split "\n" fileContent);
              in if refs == []
                 then throw ("Could not find " + file + " in " + packedRefsName)
                 else lib.head (matchRef (lib.head refs))
@@ -157,7 +173,7 @@ rec {
            else throw ("Not a .git directory: " + path);
     in readCommitFromFile "HEAD";
 
-  pathHasContext = builtins.hasContext or (lib.hasPrefix builtins.storeDir);
+  pathHasContext = builtins.hasContext or (lib.hasPrefix storeDir);
 
   canCleanSource = src: src ? _isLibCleanSourceWith || !(pathHasContext (toString src));
 }

lib/strings-with-deps.nix

@@ -41,10 +41,15 @@ Usage:
   [1] maybe this behaviour should be removed to keep things simple (?)
 */
 
-with lib.lists;
+let
-with lib.attrsets;
+  inherit (lib)
-with lib.strings;
+    concatStringsSep
-
+    head
+    isAttrs
+    listToAttrs
+    tail
+    ;
+in
 rec {
 
   /* !!! The interface of this function is kind of messed up, since

lib/strings.nix

@@ -8,7 +8,29 @@ in
 
 rec {
 
-  inherit (builtins) stringLength substring head tail isString replaceStrings;
+  inherit (builtins)
+    compareVersions
+    elem
+    elemAt
+    filter
+    fromJSON
+    head
+    isInt
+    isList
+    isString
+    match
+    parseDrvName
+    readFile
+    replaceStrings
+    split
+    storeDir
+    stringLength
+    substring
+    tail
+    toJSON
+    typeOf
+    unsafeDiscardStringContext
+    ;
 
   /* Concatenate a list of strings.
 
@@ -120,7 +142,7 @@ rec {
     subDir:
     # List of base paths
     paths:
-    concatStringsSep ":" (map (path: path + "/" + subDir) (builtins.filter (x: x != null) paths));
+    concatStringsSep ":" (map (path: path + "/" + subDir) (filter (x: x != null) paths));
 
   /* Construct a Unix-style search path by appending the given
      `subDir` to the specified `output` of each of the packages. If no
@@ -313,7 +335,7 @@ rec {
        escapeNixString "hello\${}\n"
        => "\"hello\\\${}\\n\""
   */
-  escapeNixString = s: escape ["$"] (builtins.toJSON s);
+  escapeNixString = s: escape ["$"] (toJSON s);
 
   /* Turn a string into an exact regular expression
 
@@ -337,7 +359,7 @@ rec {
   */
   escapeNixIdentifier = s:
     # Regex from https://github.com/NixOS/nix/blob/d048577909e383439c2549e849c5c2f2016c997e/src/libexpr/lexer.l#L91
-    if builtins.match "[a-zA-Z_][a-zA-Z0-9_'-]*" s != null
+    if match "[a-zA-Z_][a-zA-Z0-9_'-]*" s != null
     then s else escapeNixString s;
 
   # Obsolete - use replaceStrings instead.
@@ -466,7 +488,7 @@ rec {
        versionOlder "1.1" "1.1"
        => false
   */
-  versionOlder = v1: v2: builtins.compareVersions v2 v1 == 1;
+  versionOlder = v1: v2: compareVersions v2 v1 == 1;
 
   /* Return true if string v1 denotes a version equal to or newer than v2.
 
@@ -492,7 +514,7 @@ rec {
   */
   getName = x:
    let
-     parse = drv: (builtins.parseDrvName drv).name;
+     parse = drv: (parseDrvName drv).name;
    in if isString x
       then parse x
       else x.pname or (parse x.name);
@@ -509,7 +531,7 @@ rec {
   */
   getVersion = x:
    let
-     parse = drv: (builtins.parseDrvName drv).version;
+     parse = drv: (parseDrvName drv).version;
    in if isString x
       then parse x
       else x.version or (parse x.name);
@@ -527,7 +549,7 @@ rec {
     let
       components = splitString "/" url;
       filename = lib.last components;
-      name = builtins.head (splitString sep filename);
+      name = head (splitString sep filename);
     in assert name != filename; name;
 
   /* Create an --{enable,disable}-<feat> string that can be passed to
@@ -617,14 +639,14 @@ rec {
   */
   floatToString = float: let
     result = toString float;
-    precise = float == builtins.fromJSON result;
+    precise = float == fromJSON result;
   in if precise then result
     else lib.warn "Imprecise conversion from float to string ${result}" result;
 
   /* Check whether a value can be coerced to a string */
   isCoercibleToString = x:
-    builtins.elem (builtins.typeOf x) [ "path" "string" "null" "int" "float" "bool" ] ||
+    elem (typeOf x) [ "path" "string" "null" "int" "float" "bool" ] ||
-    (builtins.isList x && lib.all isCoercibleToString x) ||
+    (isList x && lib.all isCoercibleToString x) ||
     x ? outPath ||
     x ? __toString;
 
@@ -643,8 +665,8 @@ rec {
   isStorePath = x:
     if isCoercibleToString x then
       let str = toString x; in
-      builtins.substring 0 1 str == "/"
+      substring 0 1 str == "/"
-      && dirOf str == builtins.storeDir
+      && dirOf str == storeDir
     else
       false;
 
@@ -662,8 +684,8 @@ rec {
   */
   # Obviously, it is a bit hacky to use fromJSON this way.
   toInt = str:
-    let may_be_int = builtins.fromJSON str; in
+    let may_be_int = fromJSON str; in
-    if builtins.isInt may_be_int
+    if isInt may_be_int
     then may_be_int
     else throw "Could not convert ${str} to int.";
 
@@ -685,10 +707,10 @@ rec {
   readPathsFromFile = lib.warn "lib.readPathsFromFile is deprecated, use a list instead"
     (rootPath: file:
       let
-        lines = lib.splitString "\n" (builtins.readFile file);
+        lines = lib.splitString "\n" (readFile file);
         removeComments = lib.filter (line: line != "" && !(lib.hasPrefix "#" line));
         relativePaths = removeComments lines;
-        absolutePaths = builtins.map (path: rootPath + "/${path}") relativePaths;
+        absolutePaths = map (path: rootPath + "/${path}") relativePaths;
       in
         absolutePaths);
 
@@ -702,7 +724,7 @@ rec {
        fileContents ./version
        => "1.0"
   */
-  fileContents = file: removeSuffix "\n" (builtins.readFile file);
+  fileContents = file: removeSuffix "\n" (readFile file);
 
 
   /* Creates a valid derivation name from a potentially invalid one.
@@ -720,13 +742,13 @@ rec {
   sanitizeDerivationName = string: lib.pipe string [
     # Get rid of string context. This is safe under the assumption that the
     # resulting string is only used as a derivation name
-    builtins.unsafeDiscardStringContext
+    unsafeDiscardStringContext
     # Strip all leading "."
-    (x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0)
+    (x: elemAt (match "\\.*(.*)" x) 0)
     # Split out all invalid characters
     # https://github.com/NixOS/nix/blob/2.3.2/src/libstore/store-api.cc#L85-L112
     # https://github.com/NixOS/nix/blob/2242be83c61788b9c0736a92bb0b5c7bbfc40803/nix-rust/src/store/path.rs#L100-L125
-    (builtins.split "[^[:alnum:]+._?=-]+")
+    (split "[^[:alnum:]+._?=-]+")
     # Replace invalid character ranges with a "-"
     (concatMapStrings (s: if lib.isList s then "-" else s))
     # Limit to 211 characters (minus 4 chars for ".drv")

lib/types.nix

@@ -1,12 +1,62 @@
 # Definitions related to run-time type checking.  Used in particular
 # to type-check NixOS configurations.
 { lib }:
-with lib.lists;
+
-with lib.attrsets;
-with lib.options;
-with lib.trivial;
-with lib.strings;
 let
+  inherit (lib)
+    elem
+    flip
+    functionArgs
+    isAttrs
+    isBool
+    isDerivation
+    isFloat
+    isFunction
+    isInt
+    isList
+    isString
+    isStorePath
+    setFunctionArgs
+    toDerivation
+    toList
+    ;
+  inherit (lib.lists)
+    all
+    concatLists
+    count
+    elemAt
+    filter
+    foldl'
+    head
+    imap1
+    last
+    length
+    tail
+    unique
+    ;
+  inherit (lib.attrsets)
+    attrNames
+    filterAttrs
+    hasAttr
+    mapAttrs
+    optionalAttrs
+    zipAttrsWith
+    ;
+  inherit (lib.options)
+    getFiles
+    getValues
+    mergeDefaultOption
+    mergeEqualOption
+    mergeOneOption
+    showFiles
+    showOption
+    ;
+  inherit (lib.strings)
+    concatMapStringsSep
+    concatStringsSep
+    escapeNixString
+    isCoercibleToString
+    ;
 
   inherit (lib.modules) mergeDefinitions;
   outer_types =