Merge pull request #669 from objectionary/562-is-there-anywhere-a-col…

…lection-of-tests-for-the-input-grammar 562 is there anywhere a collection of tests for the input grammar
objectionary · Jan 17, 2025 · b792628 · b792628 · 0pdd · Jan 17, 2025
2 parents 118e509 + dd6274a
commit b792628
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diff --git a/eo-phi-normalizer/app/Main.hs b/eo-phi-normalizer/app/Main.hs
@@ -466,7 +466,7 @@ instance Show CLI'Exception where
     CouldNotParse{..} -> [fmt|An error occurred when parsing the input program:\n{message}|]
     CouldNotNormalize -> [fmt|Could not normalize the program.|]
     CouldNotMergeDependencies{..} -> message
-    Impossible{..} -> message
+    Impossible{..} -> [fmt|Impossible happened:\n{message}|]
 
 getFile :: Maybe FilePath -> IO (Maybe String)
 getFile = \case

diff --git a/eo-phi-normalizer/eo-phi-normalizer.cabal b/eo-phi-normalizer/eo-phi-normalizer.cabal
@@ -394,6 +394,7 @@ extra-source-files:
     test/eo/phi/dataization.yaml
     test/eo/phi/from-eo/as-phi.yaml
     test/eo/phi/metrics.yaml
+    test/eo/phi/parser/expressions.yaml
     test/eo/phi/rewriting.yaml
     test/eo/phi/rules/new.yaml
     test/eo/phi/rules/streams.yaml
@@ -487,6 +488,7 @@ library
     , text
     , text-manipulate
     , unordered-containers
+    , validation-selective
     , with-utf8
     , yaml
   default-language: Haskell2010
@@ -538,6 +540,7 @@ executable eo-phi-normalizer
     , text
     , text-manipulate
     , unordered-containers
+    , validation-selective
     , with-utf8
     , yaml
   default-language: Haskell2010
@@ -619,6 +622,7 @@ test-suite doctests
     , text
     , text-manipulate
     , unordered-containers
+    , validation-selective
     , with-utf8
     , yaml
   default-language: Haskell2010
@@ -628,6 +632,7 @@ test-suite spec
   main-is: Main.hs
   other-modules:
       Language.EO.Phi.DataizeSpec
+      Language.EO.Phi.ParserSpec
       Language.EO.Phi.RewriteSpec
       Language.EO.PhiSpec
       Language.EO.Rules.PhiPaperSpec
@@ -679,6 +684,7 @@ test-suite spec
     , text
     , text-manipulate
     , unordered-containers
+    , validation-selective
     , with-utf8
     , yaml
   default-language: Haskell2010
diff --git a/eo-phi-normalizer/grammar/EO/Phi/Syntax.cf b/eo-phi-normalizer/grammar/EO/Phi/Syntax.cf
@@ -30,15 +30,15 @@ comment "//" ;
 comment "/*" "*/" ;
 
 token Bytes ({"--"} | ["0123456789ABCDEF"] ["0123456789ABCDEF"] {"-"} | ["0123456789ABCDEF"] ["0123456789ABCDEF"] ({"-"} ["0123456789ABCDEF"] ["0123456789ABCDEF"])+) ;
-token Function upper (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦"])* ;
-token LabelId  lower (char - [" \r\n\t,.|':;!?][}{)(⟧⟦"])* ;
+token Function upper (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦↦"])* ;
+token LabelId  lower (char - [" \r\n\t,.|':;!?][}{)(⟧⟦↦"])* ;
 token AlphaIndex ({"α0"} | {"α"} (digit - ["0"]) (digit)* ) ;
-token LabelMetaId {"!τ"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦"])* ;
-token TailMetaId {"!t"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦"])* ;
-token BindingsMetaId {"!B"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦"])* ;
-token ObjectMetaId {"!b"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦"])* ;
-token BytesMetaId {"!y"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦"])* ;
-token MetaFunctionName {"@"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦"])* ;
+token LabelMetaId {"!τ"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦↦"])* ;
+token TailMetaId {"!t"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦↦"])* ;
+token BindingsMetaId {"!B"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦↦"])* ;
+token ObjectMetaId {"!b"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦↦"])* ;
+token BytesMetaId {"!y"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦↦"])* ;
+token MetaFunctionName {"@"} (char - [" \r\n\t,.|':;!-?][}{)(⟧⟦↦"])* ;
 token IntegerSigned ('-'? digit+) ;
 token DoubleSigned ('-'? digit+ '.' digit+ ('e' '-'? digit+)?) ;
 token StringRaw '"' ((char - ["\"\\"]) | ('\\' ["\"\\tnrfu"]))* '"';
@@ -71,7 +71,7 @@ internal ConstFloat.    Object ::= Double;
 internal ConstInt.      Object ::= Integer;
 internal ConstString.   Object ::= String;
 
-AlphaBinding.       Binding ::= Attribute "↦" Object ;
+AlphaBinding.       Binding ::= AttributeSugar "↦" Object ;
 AlphaBindingSugar.  Binding ::= Object ;
 EmptyBinding.       Binding ::= Attribute "↦" "∅" ;
 DeltaBinding.       Binding ::= "Δ" "⤍" Bytes ;
@@ -81,14 +81,15 @@ MetaBindings.       Binding ::= BindingsMetaId ;
 MetaDeltaBinding.   Binding ::= "Δ" "⤍" BytesMetaId ;
 separator Binding "," ;
 
+AttributeNoSugar.   AttributeSugar ::= "#" Attribute;
+AttributeSugar.     AttributeSugar ::= "~" LabelId "(" [Attribute] ")";
+separator Attribute ",";
+
 Phi.    Attribute ::= "φ" ;   -- decoratee object
-PhiSugar. Attribute ::= "~" "φ" "(" [LabelId] ")";
 Rho.    Attribute ::= "ρ" ;   -- parent object
 Label.  Attribute ::= LabelId ;
 Alpha.  Attribute ::= AlphaIndex ;
 MetaAttr. Attribute ::= LabelMetaId ;
-AttrSugar. Attribute ::= "~" LabelId "(" [LabelId] ")";
-separator LabelId ",";
 
 -- Additional symbols used as attributes in the rules
 ObjectAttr. RuleAttribute ::= Attribute ;

diff --git a/eo-phi-normalizer/package.yaml b/eo-phi-normalizer/package.yaml
@@ -97,6 +97,7 @@ dependencies:
   - megaparsec
   - parser-combinators
   - prettyprinter
+  - validation-selective
 
 default-extensions:
   - ImportQualifiedPost

diff --git a/eo-phi-normalizer/src/Language/EO/Phi/Dataize.hs b/eo-phi-normalizer/src/Language/EO/Phi/Dataize.hs
@@ -108,7 +108,7 @@ dataizeStepChain mode obj@(Formation bs)
               ctx <- getContext
               return (ctx, AsObject obj')
   | DataizeAll <- mode
-  , Just (AlphaBinding Phi decoratee) <- listToMaybe [b | b@(AlphaBinding Phi _) <- bs]
+  , Just (AlphaBinding' Phi decoratee) <- listToMaybe [b | b@(AlphaBinding' Phi _) <- bs]
   , not hasEmpty = do
       let decoratee' = substThis obj decoratee
       logStep "Dataizing inside phi" (AsObject decoratee')

diff --git a/eo-phi-normalizer/src/Language/EO/Phi/Dataize/Atoms.hs b/eo-phi-normalizer/src/Language/EO/Phi/Dataize/Atoms.hs
@@ -163,11 +163,11 @@ knownAtomsList =
          where
           isPackage (LambdaBinding (Function "Package")) = True
           isPackage _ = False
-          dataizeBindingChain (AlphaBinding attr o) = do
+          dataizeBindingChain (AlphaBinding' attr o) = do
             ctx <- getContext
             let extendedContext = (extendContextWith obj ctx){currentAttr = attr}
             dataizationResult <- incLogLevel $ withContext extendedContext $ dataizeRecursivelyChain False o
-            return (AlphaBinding attr (either id (Formation . singleton . DeltaBinding) dataizationResult))
+            return (AlphaBinding' attr (either id (Formation . singleton . DeltaBinding) dataizationResult))
           dataizeBindingChain b = return b
         f name _otherwise = evaluateBuiltinFunChainUnknown name _otherwise
        in

diff --git a/eo-phi-normalizer/src/Language/EO/Phi/Dependencies.hs b/eo-phi-normalizer/src/Language/EO/Phi/Dependencies.hs
@@ -30,7 +30,8 @@ import Language.EO.Phi
 import Control.Monad (foldM)
 
 bindingAttr :: Binding -> Maybe Attribute
-bindingAttr (AlphaBinding a _) = Just a
+bindingAttr (AlphaBinding' a _) = Just a
+bindingAttr b@(AlphaBinding _ _) = errorExpectedDesugaredBinding b
 bindingAttr (EmptyBinding a) = Just a
 bindingAttr (DeltaBinding _) = Just (Alpha (AlphaIndex "Δ"))
 bindingAttr DeltaEmptyBinding = Just (Alpha (AlphaIndex "Δ"))

diff --git a/eo-phi-normalizer/src/Language/EO/Phi/Metrics/Collect.hs b/eo-phi-normalizer/src/Language/EO/Phi/Metrics/Collect.hs
@@ -29,6 +29,7 @@
 {-# LANGUAGE InstanceSigs #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedLabels #-}
+{-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE UndecidableInstances #-}
@@ -43,6 +44,7 @@ import Data.Maybe (catMaybes)
 import Data.Traversable (forM)
 import Language.EO.Phi.Metrics.Data (BindingMetrics (..), BindingsByPathMetrics (..), MetricsCount, ObjectMetrics (..), Path, ProgramMetrics (..))
 import Language.EO.Phi.Rules.Common ()
+import Language.EO.Phi.Syntax (pattern AlphaBinding')
 import Language.EO.Phi.Syntax.Abs
 
 -- $setup
@@ -158,12 +160,12 @@ getThisObjectMetrics obj = execState (inspect obj) mempty
 
 -- | Get an object by a path within a given object.
 --
--- If no object is accessible by the path, return a prefix of the path that led to a non-formation when the remaining path wasn't empty.
+-- If no object is accessible by the path, return the path that led to a non-formation.
 -- >>> flip getObjectByPath ["org", "eolang"] "⟦ org ↦ ⟦ eolang ↦ ⟦ x ↦ ⟦ φ ↦ Φ.org.eolang.bool ( α0 ↦ Φ.org.eolang.bytes (Δ ⤍ 01-) ) ⟧, z ↦ ⟦ y ↦ ⟦ x ↦ ∅, φ ↦ ξ.x ⟧, φ ↦ Φ.org.eolang.bool ( α0 ↦ Φ.org.eolang.bytes (Δ ⤍ 01-) ) ⟧, λ ⤍ Package ⟧, λ ⤍ Package ⟧⟧"
--- Right (Formation [AlphaBinding (Label (LabelId "x")) (Formation [AlphaBinding Phi (Application (ObjectDispatch (ObjectDispatch (ObjectDispatch GlobalObject (Label (LabelId "org"))) (Label (LabelId "eolang"))) (Label (LabelId "bool"))) [AlphaBinding (Alpha (AlphaIndex "\945\&0")) (Application (ObjectDispatch (ObjectDispatch (ObjectDispatch GlobalObject (Label (LabelId "org"))) (Label (LabelId "eolang"))) (Label (LabelId "bytes"))) [DeltaBinding (Bytes "01-")])])]),AlphaBinding (Label (LabelId "z")) (Formation [AlphaBinding (Label (LabelId "y")) (Formation [EmptyBinding (Label (LabelId "x")),AlphaBinding Phi (ObjectDispatch ThisObject (Label (LabelId "x")))]),AlphaBinding Phi (Application (ObjectDispatch (ObjectDispatch (ObjectDispatch GlobalObject (Label (LabelId "org"))) (Label (LabelId "eolang"))) (Label (LabelId "bool"))) [AlphaBinding (Alpha (AlphaIndex "\945\&0")) (Application (ObjectDispatch (ObjectDispatch (ObjectDispatch GlobalObject (Label (LabelId "org"))) (Label (LabelId "eolang"))) (Label (LabelId "bytes"))) [DeltaBinding (Bytes "01-")])])]),LambdaBinding (Function "Package")])
+-- Right (Formation [AlphaBinding (AttributeNoSugar (Label (LabelId "x"))) (Formation [AlphaBinding (AttributeNoSugar Phi) (Application (ObjectDispatch (ObjectDispatch (ObjectDispatch GlobalObject (Label (LabelId "org"))) (Label (LabelId "eolang"))) (Label (LabelId "bool"))) [AlphaBinding (AttributeNoSugar (Alpha (AlphaIndex "\945\&0"))) (Application (ObjectDispatch (ObjectDispatch (ObjectDispatch GlobalObject (Label (LabelId "org"))) (Label (LabelId "eolang"))) (Label (LabelId "bytes"))) [DeltaBinding (Bytes "01-")])])]),AlphaBinding (AttributeNoSugar (Label (LabelId "z"))) (Formation [AlphaBinding (AttributeNoSugar (Label (LabelId "y"))) (Formation [EmptyBinding (Label (LabelId "x")),AlphaBinding (AttributeNoSugar Phi) (ObjectDispatch ThisObject (Label (LabelId "x")))]),AlphaBinding (AttributeNoSugar Phi) (Application (ObjectDispatch (ObjectDispatch (ObjectDispatch GlobalObject (Label (LabelId "org"))) (Label (LabelId "eolang"))) (Label (LabelId "bool"))) [AlphaBinding (AttributeNoSugar (Alpha (AlphaIndex "\945\&0"))) (Application (ObjectDispatch (ObjectDispatch (ObjectDispatch GlobalObject (Label (LabelId "org"))) (Label (LabelId "eolang"))) (Label (LabelId "bytes"))) [DeltaBinding (Bytes "01-")])])]),LambdaBinding (Function "Package")])
 --
 -- >>> flip getObjectByPath ["a"] "⟦ a ↦ ⟦ b ↦ ⟦ c ↦ ∅, d ↦ ⟦ φ ↦ ξ.ρ.c ⟧ ⟧, e ↦ ξ.b(c ↦ ⟦⟧).d ⟧.e ⟧"
--- Right (ObjectDispatch (Formation [AlphaBinding (Label (LabelId "b")) (Formation [EmptyBinding (Label (LabelId "c")),AlphaBinding (Label (LabelId "d")) (Formation [AlphaBinding Phi (ObjectDispatch (ObjectDispatch ThisObject Rho) (Label (LabelId "c")))])]),AlphaBinding (Label (LabelId "e")) (ObjectDispatch (Application (ObjectDispatch ThisObject (Label (LabelId "b"))) [AlphaBinding (Label (LabelId "c")) (Formation [])]) (Label (LabelId "d")))]) (Label (LabelId "e")))
+-- Left ["a"]
 getObjectByPath :: Object -> Path -> Either Path Object
 getObjectByPath object path =
   case path of
@@ -180,15 +182,15 @@ getObjectByPath object path =
               x <- bindings
               Right obj <-
                 case x of
-                  AlphaBinding (Alpha (AlphaIndex name)) obj | name == p -> [getObjectByPath obj ps]
-                  AlphaBinding (Label (LabelId name)) obj | name == p -> [getObjectByPath obj ps]
+                  AlphaBinding' (Alpha (AlphaIndex name)) obj@(Formation{}) | name == p -> [getObjectByPath obj ps]
+                  AlphaBinding' (Label (LabelId name)) obj@(Formation{}) | name == p -> [getObjectByPath obj ps]
                   _ -> [Left path]
               pure obj
         _ -> Left path
 
 -- | Get metrics for bindings of a formation that is accessible by a path within a given object.
 --
--- If no formation is accessible by the path, return a prefix of the path that led to a non-formation when the remaining path wasn't empty.
+-- If no formation is accessible by the path, return the path that led to a non-formation.
 -- >>> flip getBindingsByPathMetrics ["a"] "⟦ a ↦ ⟦ b ↦ ⟦ c ↦ ∅, d ↦ ⟦ φ ↦ ξ.ρ.c ⟧ ⟧, e ↦ ξ.b(c ↦ ⟦⟧).d ⟧.e ⟧"
 -- Left ["a"]
 --
@@ -203,8 +205,8 @@ getBindingsByPathMetrics object path =
           bindingsMetrics = do
             x <- zip bindings objectMetrics
             case x of
-              (AlphaBinding (Alpha (AlphaIndex name)) _, metrics) -> [BindingMetrics{..}]
-              (AlphaBinding (Label (LabelId name)) _, metrics) -> [BindingMetrics{..}]
+              (AlphaBinding' (Alpha (AlphaIndex name)) _, metrics) -> [BindingMetrics{..}]
+              (AlphaBinding' (Label (LabelId name)) _, metrics) -> [BindingMetrics{..}]
               _ -> []
        in Right $ BindingsByPathMetrics{..}
     Right _ -> Left path
@@ -214,7 +216,7 @@ getBindingsByPathMetrics object path =
 --
 -- Combine metrics produced by 'getThisObjectMetrics' and 'getBindingsByPathMetrics'.
 --
--- If no formation is accessible by the path, return a prefix of the path that led to a non-formation when the remaining path wasn't empty.
+-- If no formation is accessible by the path, return the path that led to a non-formation.
 -- >>> flip getObjectMetrics (Just ["a"]) "⟦ a ↦ ⟦ b ↦ ⟦ c ↦ ∅, d ↦ ⟦ φ ↦ ξ.ρ.c ⟧ ⟧, e ↦ ξ.b(c ↦ ⟦⟧).d ⟧.e ⟧"
 -- Left ["a"]
 --
@@ -223,14 +225,14 @@ getBindingsByPathMetrics object path =
 getObjectMetrics :: Object -> Maybe Path -> Either Path ObjectMetrics
 getObjectMetrics object path = do
   let thisObjectMetrics = getThisObjectMetrics object
-  bindingsByPathMetrics <- forM path $ \path' -> getBindingsByPathMetrics object path'
+  bindingsByPathMetrics <- forM path $ getBindingsByPathMetrics object
   pure ObjectMetrics{..}
 
--- | Get metrics for a program and for bindings of a formation accessible by a given path.
+-- | Get metrics for a program and for bindings of a formation accessible by the given path.
 --
 -- Combine metrics produced by 'getThisObjectMetrics' and 'getBindingsByPathMetrics'.
 --
--- If no formation is accessible by the path, return a prefix of the path that led to a non-formation when the remaining path wasn't empty.
+-- If no formation is accessible by the path, return the path that led to a non-formation.
 -- >>> flip getProgramMetrics (Just ["org", "eolang"]) "{⟦ org ↦ ⟦ eolang ↦ ⟦ x ↦ ⟦ φ ↦ Φ.org.eolang.bool ( α0 ↦ Φ.org.eolang.bytes (Δ ⤍ 01-) ) ⟧, z ↦ ⟦ y ↦ ⟦ x ↦ ∅, φ ↦ ξ.x ⟧, φ ↦ Φ.org.eolang.bool ( α0 ↦ Φ.org.eolang.bytes (Δ ⤍ 01-) ) ⟧, λ ⤍ Package ⟧, λ ⤍ Package ⟧⟧ }"
 -- Right (ProgramMetrics {bindingsByPathMetrics = Just (BindingsByPathMetrics {path = ["org","eolang"], bindingsMetrics = [BindingMetrics {name = "x", metrics = Metrics {dataless = 1, applications = 2, formations = 1, dispatches = 6}},BindingMetrics {name = "z", metrics = Metrics {dataless = 2, applications = 2, formations = 2, dispatches = 7}}]}), programMetrics = Metrics {dataless = 6, applications = 4, formations = 6, dispatches = 13}})
 --

diff --git a/eo-phi-normalizer/src/Language/EO/Phi/Preprocess.hs b/eo-phi-normalizer/src/Language/EO/Phi/Preprocess.hs
@@ -22,15 +22,17 @@
 -- SOFTWARE.
 {- FOURMOLU_ENABLE -}
 {-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE LambdaCase #-}
 
 module Language.EO.Phi.Preprocess where
 
 import Control.Monad (void)
 import Data.Void (Void)
+import Language.EO.Phi.Syntax.Abs
 import Replace.Megaparsec (splitCap)
-import Text.Megaparsec (MonadParsec (..), Parsec, Stream (..), between, match, sepBy)
+import Text.Megaparsec (MonadParsec (..), Parsec, Stream (..), between, choice, match, oneOf, optional, sepBy)
 import Text.Megaparsec.Byte.Lexer qualified as L
-import Text.Megaparsec.Char (lowerChar, space)
+import Text.Megaparsec.Char (space, string)
 
 symbol :: String -> Parser String
 symbol = L.symbol space
@@ -40,41 +42,96 @@ lexeme = L.lexeme space
 
 type Parser = Parsec Void String
 
-parseLabelId :: Parser ()
+parseTail :: Parser String
+parseTail = takeWhileP (Just "LabelId") (`notElem` " \r\n\t,.|':;!?][}{)(⟧⟦↦")
+
+parseLabelId :: Parser LabelId
 parseLabelId = lexeme do
-  void lowerChar
-  void $ takeWhileP (Just "LabelId") (`notElem` " \r\n\t,.|':;!?][}{)(⟧⟦")
+  l <- oneOf ['a' .. 'z']
+  ls <- parseTail
+  pure $ LabelId (l : ls)
+
+parseToken :: String -> (String -> a) -> Parser a
+parseToken prefix cons = lexeme do
+  void $ string prefix
+  ls <- parseTail
+  pure $ cons (prefix <> ls)
+
+parseObjectMetaId :: Parser ObjectMetaId
+parseObjectMetaId = parseToken "!b" ObjectMetaId
+
+parseBytesMetaId :: Parser BytesMetaId
+parseBytesMetaId = parseToken "!y" BytesMetaId
+
+parseLabelMetaId :: Parser LabelMetaId
+parseLabelMetaId = parseToken "!τ" LabelMetaId
+
+parseMetaId :: Parser MetaId
+parseMetaId =
+  choice
+    [ MetaIdObject <$> parseObjectMetaId
+    , MetaIdBytes <$> parseBytesMetaId
+    , MetaIdLabel <$> parseLabelMetaId
+    ]
+
+parseAlphaIndex :: Parser AlphaIndex
+parseAlphaIndex = parseToken "α" AlphaIndex
+
+parseAttribute :: Parser Attribute
+parseAttribute = lexeme do
+  choice
+    [ Phi <$ symbol "φ"
+    , Rho <$ symbol "ρ"
+    , Label <$> parseLabelId
+    , Alpha <$> parseAlphaIndex
+    ]
 
 parseBindingArrow :: Parser ()
 parseBindingArrow = void $ symbol "↦"
 
-parseAlphaAttr :: Parser ()
-parseAlphaAttr = do
-  void parseLabelId
-  void $ between (symbol "(") (symbol ")") (sepBy parseLabelId (symbol ","))
-
-parseAlphaBindingSugar :: Parser ()
+parseAttributeSugar :: Parser AttributeSugar
+parseAttributeSugar = do
+  choice
+    [ do
+        labelId <- parseLabelId
+        attrs <- optional $ between (symbol "(") (symbol ")") (sepBy parseAttribute (symbol ","))
+        case attrs of
+          Nothing -> pure $ AttributeNoSugar (Label labelId)
+          Just attrs' -> pure $ AttributeSugar labelId attrs'
+    , AttributeNoSugar <$> parseAttribute
+    ]
+
+type Attr = Either MetaId AttributeSugar
+
+parseAlphaBindingSugar :: Parser Attr
 parseAlphaBindingSugar = do
-  parseAlphaAttr
+  attr <-
+    choice
+      [ Left <$> parseMetaId
+      , Right <$> parseAttributeSugar
+      ]
   parseBindingArrow
+  notFollowedBy (symbol "∅")
+  pure attr
 
-splitInput :: Parser a -> String -> [Either String (Tokens [Char])]
-splitInput sep = splitCap (fst <$> match sep)
+splitInput :: Parser a -> String -> [Either String (Tokens [Char], a)]
+splitInput sep = splitCap (match sep)
 
-addPrefix :: Parser a -> String -> [String]
-addPrefix sep = map (either id ("~" <>)) . splitInput sep
+addPrefix :: Parser Attr -> String -> [String]
+addPrefix sep = fmap (either id (\(x, a) -> choosePrefix a <> x)) . splitInput sep
+ where
+  choosePrefix = \case
+    Right AttributeSugar{} -> "~"
+    _ -> "#"
 
-preprocess' :: Parser a -> String -> String
+preprocess' :: Parser Attr -> String -> String
 preprocess' sep = concat . addPrefix sep
 
 preprocess :: String -> String
 preprocess = preprocess' parseAlphaBindingSugar
 
 input1 :: String
-input1 = "{⟦ org ↦ ⟦ eolang ↦ ⟦ number( as-bytes, abra  ) ↦ ⟦ φ ↦ ξ.as-bytes, neg ↦ ξ.times(-1), ⟧, λ ⤍ Package ⟧, λ ⤍ Package ⟧ ⟧}"
-
--- >>> addPrefix parseAlphaBindingSugar input1
--- ["{\10214 org \8614 \10214 eolang \8614 \10214 ","~number( as-bytes, abra  ) \8614 ","\10214 \966 \8614 \958.as-bytes, neg \8614 \958.times(-1), \10215, \955 \10509 Package \10215, \955 \10509 Package \10215 \10215}"]
+input1 = "{⟦ org ↦ ⟦ ⟧(α0 ↦ !b1) ⟧}"
 
 -- >>> preprocess input1
--- "{\10214 org \8614 \10214 eolang \8614 \10214 ~number( as-bytes, abra  ) \8614 \10214 \966 \8614 \958.as-bytes, neg \8614 \958.times(-1), \10215, \955 \10509 Package \10215, \955 \10509 Package \10215 \10215}"
+-- "{\10214 #org \8614 \10214 \10215(#\945\&0 \8614 !b1) \10215}"