From afa6c51f27fb86fda71f91a51b093a5fc3de797d Mon Sep 17 00:00:00 2001 From: Robert Hensing Date: Tue, 20 Oct 2020 13:47:24 +0200 Subject: 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/strings.nix | 64 ++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 43 insertions(+), 21 deletions(-) (limited to 'lib/strings.nix') diff --git a/lib/strings.nix b/lib/strings.nix index d81e46a1763..f62ff6679ef 100644 --- a/lib/strings.nix +++ b/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}- 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" ] || - (builtins.isList x && lib.all isCoercibleToString x) || + elem (typeOf x) [ "path" "string" "null" "int" "float" "bool" ] || + (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 == "/" - && dirOf str == builtins.storeDir + substring 0 1 str == "/" + && 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 - if builtins.isInt may_be_int + let may_be_int = fromJSON str; in + 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") -- cgit 1.4.1