compiler/SourceSyntax/Location.hs · elk

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1{-# LANGUAGE DeriveDataTypeable #-}

2module SourceSyntax.Location where

4import Text.Parsec.Pos

5import Data.Data

7data SrcPos = Pos Int Int

8 deriving (Eq, Ord, Data, Typeable)

10data SrcSpan = Span SrcPos SrcPos | NoSpan

11 deriving (Eq, Ord, Data, Typeable)

13data Located e = L (Maybe String) SrcSpan e

14 deriving (Eq, Ord, Data, Typeable)

17instance Show SrcPos where

18 show (Pos r c) = "Line " ++ show r ++ ", Column " ++ show c

20instance Show SrcSpan where

21 show span =

22 case span of

23 Span start end -> show start

24 NoSpan -> ""

26instance Show e => Show (Located e) where

27 show (L _ _ e) = show e

31none = L Nothing NoSpan

33at start end = L Nothing

34 (Span (Pos (sourceLine start) (sourceColumn start))

35 (Pos (sourceLine end ) (sourceColumn end )))

37merge (L _ s1 _) (L _ s2 _) = L Nothing span

38 where span = case (s1,s2) of

39 (Span start _, Span _ end) -> Span start end

40 (_, NoSpan) -> s1

41 (NoSpan, _) -> s2

43add x (L Nothing span e) = L (Just (show x)) span e

44add x (L txt span e) = L txt span e