src/Reporting/PrettyPrint.hs · elk

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elk/src/Reporting/PrettyPrint.hs

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1{-# LANGUAGE FlexibleInstances #-}

2module Reporting.PrettyPrint where

4import Text.PrettyPrint as P

5import qualified AST.Helpers as Help

8class Pretty a where

9 pretty :: Bool -> a -> Doc

12instance Pretty String where

13 pretty _ str =

14 P.text str

17commaCat :: [Doc] -> Doc

18commaCat docs =

19 cat (punctuate comma docs)

22commaSep :: [Doc] -> Doc

23commaSep docs =

24 sep (punctuate comma docs)

27parensIf :: Bool -> Doc -> Doc

28parensIf bool doc =

29 if bool then parens doc else doc

32variable :: String -> Doc

33variable x =

34 if Help.isOp x then parens (text x) else text x

37eightyCharLines :: Int -> String -> String

38eightyCharLines indent message = answer

39 where

40 (answer,_,_) = foldl step (spaces, indent-1, "") chunks

42 chunks = map (\w -> (w, length w)) (words message)

43 spaces = replicate indent ' '

44 step (sentence, slen, space) (word, wlen)

45 | slen + wlen > 79 = (sentence ++ "\n" ++ spaces ++ word, indent + wlen, " ")

46 | otherwise = (sentence ++ space ++ word, slen + wlen + length space, " ")