never executed always true always false

    1 {-# LANGUAGE TypeFamilies #-}
    2 {-# LANGUAGE DataKinds #-}
    3 {-# LANGUAGE DeriveGeneric #-}
    4 module ElmFormat.AST.Shared where
    5 
    6 import Data.Coapplicative
    7 import Data.Int (Int64)
    8 import GHC.Generics
    9 import Data.Text (Text)
   10 import qualified Data.Text as Text
   11 import qualified Data.Tuple as Tuple
   12 import qualified Data.Char as Char
   13 
   14 {-| This module contains types that are used by multiple versions of the Elm AST.
   15 -}
   16 
   17 
   18 type List a = [a]
   19 
   20 
   21 newtype LowercaseIdentifier =
   22     LowercaseIdentifier String
   23     deriving (Eq, Ord)
   24 
   25 instance Show LowercaseIdentifier where
   26     show (LowercaseIdentifier name) = name
   27 
   28 
   29 newtype UppercaseIdentifier =
   30     UppercaseIdentifier String
   31     deriving (Eq, Ord, Show)
   32 
   33 
   34 newtype SymbolIdentifier =
   35     SymbolIdentifier String
   36     deriving (Eq, Ord, Show)
   37 
   38 
   39 data Commented c a =
   40     C c a
   41     deriving (Eq, Ord, Functor, Show) -- TODO: is Ord needed?
   42 
   43 instance Coapplicative (Commented c) where
   44     extract (C _ a) = a
   45     {-# INLINE extract #-}
   46 
   47 
   48 data IntRepresentation
   49   = DecimalInt
   50   | HexadecimalInt
   51   deriving (Eq, Show, Generic)
   52 
   53 
   54 data FloatRepresentation
   55   = DecimalFloat
   56   | ExponentFloat
   57   deriving (Eq, Show, Generic)
   58 
   59 
   60 data StringRepresentation
   61     = SingleQuotedString
   62     | TripleQuotedString
   63     deriving (Eq, Show, Generic)
   64 
   65 
   66 data LiteralValue
   67     = IntNum Int64 IntRepresentation
   68     | FloatNum Double FloatRepresentation
   69     | Chr Char
   70     | Str String StringRepresentation
   71     | Boolean Bool
   72     deriving (Eq, Show)
   73 
   74 
   75 data Ref ns
   76     = VarRef ns LowercaseIdentifier
   77     | TagRef ns UppercaseIdentifier
   78     | OpRef SymbolIdentifier
   79     deriving (Eq, Ord, Show, Functor)
   80 
   81 refFromText :: Text -> Maybe (Ref ())
   82 refFromText text =
   83     case Tuple.fst <$> Text.uncons text of
   84         Just first | Char.isUpper first ->
   85             Just $ TagRef () (UppercaseIdentifier $ Text.unpack text)
   86 
   87         Just first | Char.isLower first ->
   88             Just $ VarRef () (LowercaseIdentifier $ Text.unpack text)
   89 
   90         Just _ ->
   91             Just $ OpRef (SymbolIdentifier $ Text.unpack text)
   92 
   93         Nothing ->
   94             Nothing
   95 
   96 
   97 data UnaryOperator =
   98     Negative
   99     deriving (Eq, Show)