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 deriving (Eq,Ord, Data, Typeable)

16instance Show SrcPos where

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

19instance Show SrcSpan where

20 show span =

21 case span of

22 Span start end -> show start

23 NoSpan -> ""

25instance Show e => Show (Located e) where

26 show (L _ _ e) = show e

30none = L Nothing NoSpan

32at start end = L Nothing

33 (Span (Pos (sourceLine start) (sourceColumn start))

34 (Pos (sourceLine end ) (sourceColumn end )))

36merge (L _ s1 _) (L _ s2 _) = L Nothing span

37 where span = case (s1,s2) of

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

39 (_, NoSpan) -> s1

40 (NoSpan, _) -> s2

42add x (L Nothing span e) = L (Just (show x)) span e

43add x (L txt span e) = L txt span e