Parse inherit names with quotes

.gitignore

@@ -9,3 +9,6 @@
 /dist-newstyle
 /.ghc.environment.*
 /result
+tags
+Tags
+TAGS

CHANGELOG.md

@@ -15,6 +15,7 @@
 * Nixfmt now accepts the '-' argument to read from stdin.
 * `nixfmt [dir]` now recursively formats nix files in that directory.
 * Float and int literal parsing now matches nix.
+* Add support for quoted inherit names.
 
 ## 0.5.0 -- 2022-03-15
 

src/Nixfmt/Parser.hs

@@ -4,7 +4,7 @@
  - SPDX-License-Identifier: MPL-2.0
  -}
 
-{-# LANGUAGE LambdaCase, OverloadedStrings #-}
+{-# LANGUAGE BlockArguments, LambdaCase, OverloadedStrings #-}
 
 module Nixfmt.Parser where
 
@@ -26,9 +26,10 @@ import qualified Text.Megaparsec.Char.Lexer as L (decimal)
 
 import Nixfmt.Lexer (lexeme)
 import Nixfmt.Types
-  (Ann, Binder(..), Expression(..), File(..), Fixity(..), Leaf, Operator(..),
+  (Ann(..), Binder(..), Expression(..), File(..), Fixity(..), Leaf, Operator(..),
   ParamAttr(..), Parameter(..), Parser, Path, Selector(..), SimpleSelector(..),
-  String, StringPart(..), Term(..), Token(..), operators, tokenText)
+  String, StringPart(..), Term(..), Token(..), operators, reservedNames,
+  toLeading, tokenText)
 import Nixfmt.Parser.Float (floatParse)
 import Nixfmt.Util
   (commonIndentation, identChar, isSpaces, manyP, manyText, pathChar,
@@ -46,16 +47,6 @@ rawSymbol t = chunk (tokenText t) *> return t
 symbol :: Token -> Parser (Ann Token)
 symbol = lexeme . rawSymbol
 
-reservedNames :: [Text]
-reservedNames =
-    [ "let", "in"
-    , "if", "then", "else"
-    , "assert"
-    , "with"
-    , "rec"
-    , "inherit"
-    ]
-
 reserved :: Token -> Parser (Ann Token)
 reserved t = try $ lexeme $ rawSymbol t
     <* lookAhead (satisfy (\x -> not $ identChar x || pathChar x))
@@ -68,13 +59,33 @@ integer = ann Integer L.decimal
 float :: Parser (Ann Token)
 float = ann Float floatParse
 
+rawIdentifier :: Parser Text
+rawIdentifier = Text.cons
+    <$> satisfy (\x -> isAlpha x || x == '_')
+    <*> manyP identChar
+
 identifier :: Parser (Ann Token)
-identifier = ann Identifier $ do
-    ident <- Text.cons <$> satisfy (\x -> isAlpha x || x == '_')
-                       <*> manyP identChar
+identifier = ann Identifier do
+    ident <- rawIdentifier
     guard $ not $ ident `elem` reservedNames
     return ident
 
+-- Support all of: { inherit foo "bar" ${"baz"}; }
+fancyIdentifier :: Parser (Ann Token)
+fancyIdentifier = identifier <|> stringIdentifier <|> curlyIdentifier
+
+stringIdentifier :: Parser (Ann Token)
+stringIdentifier = ann Identifier do
+    rawSymbol TDoubleQuote *> rawIdentifier <* rawSymbol TDoubleQuote
+
+curlyIdentifier :: Parser (Ann Token)
+curlyIdentifier = do
+    (Ann _ trailing1 leading1) <- symbol TInterOpen
+    (Ann i trailing2 leading2) <- stringIdentifier
+    (Ann _ trailing3 leading3) <- symbol TInterClose
+    pure $ Ann i trailing1 $
+      leading1 <> toLeading trailing2 <> leading2 <> toLeading trailing3 <> leading3
+
 slash :: Parser Text
 slash = chunk "/" <* notFollowedBy (char '/')
 
@@ -271,7 +282,7 @@ abstraction = try (Abstraction <$>
 
 inherit :: Parser Binder
 inherit = Inherit <$> reserved KInherit <*> optional parens <*>
-    many identifier <*> symbol TSemicolon
+    many fancyIdentifier <*> symbol TSemicolon
 
 assignment :: Parser Binder
 assignment = Assignment <$>

src/Nixfmt/Pretty.hs

@@ -22,7 +22,7 @@ import Nixfmt.Predoc
 import Nixfmt.Types
   (Ann(..), Binder(..), Expression(..), File(..), Leaf, ParamAttr(..),
   Parameter(..), Selector(..), SimpleSelector(..), StringPart(..), Term(..),
-  Token(..), TrailingComment(..), Trivia, Trivium(..), tokenText)
+  Token(..), TrailingComment(..), Trivium(..), toLeading, tokenText)
 import Nixfmt.Util (commonIndentation, isSpaces, replaceMultiple)
 
 prettyCommentLine :: Text -> Doc
@@ -120,10 +120,6 @@ instance Pretty Term where
     pretty l@(List _ _ _) = group $ prettyTerm l
     pretty x              = prettyTerm x
 
-toLeading :: Maybe TrailingComment -> Trivia
-toLeading Nothing = []
-toLeading (Just (TrailingComment c)) = [LineComment (" " <> c)]
-
 prettyComma :: Maybe Leaf -> Doc
 prettyComma Nothing = mempty
 prettyComma (Just comma) = softline' <> pretty comma <> hardspace

src/Nixfmt/Types.hs

@@ -30,6 +30,10 @@ type Trivia = [Trivium]
 
 newtype TrailingComment = TrailingComment Text deriving (Eq, Show)
 
+toLeading :: Maybe TrailingComment -> Trivia
+toLeading Nothing = []
+toLeading (Just (TrailingComment c)) = [LineComment (" " <> c)]
+
 data Ann a
     = Ann a (Maybe TrailingComment) Trivia
     deriving (Show)
@@ -204,7 +208,19 @@ operators =
     , [ Op InfixL TImplies ]
     ]
 
+reservedNames :: [Text]
+reservedNames =
+    [ "let", "in"
+    , "if", "then", "else"
+    , "assert"
+    , "with"
+    , "rec"
+    , "inherit"
+    ]
+
 tokenText :: Token -> Text
+tokenText (Identifier i)
+    | i `elem` reservedNames = "\"" <> i <> "\""
 tokenText (Identifier i)     = i
 tokenText (Integer i)        = pack (show i)
 tokenText (Float f)          = pack (show f)

test/changed/quotes-in-inherit.in.nix

@@ -0,0 +1,7 @@
+let
+  foo = 1;
+  "bar" = 2;
+  ${"baz"} = 3;
+  ${"in"} = 4;
+
+in { inherit ${"foo"} bar "baz" "in"; }

test/changed/quotes-in-inherit.out.nix

@@ -0,0 +1,7 @@
+let
+  foo = 1;
+  bar = 2;
+  baz = 3;
+  "in" = 4;
+
+in { inherit foo bar baz "in"; }

test/correct/quotes-in-inherit.nix

@@ -0,0 +1 @@
+{ inherit ({ "in" = 1; }) "in"; }

test/invalid/interpolation-in-inherit-1.nix

@@ -0,0 +1,4 @@
+let
+  bar = "bar";
+
+in { inherit ${bar}; }

test/invalid/interpolation-in-inherit-2.nix

@@ -0,0 +1 @@
+{ inherit ${"foo" + "bar"}; }