blob: ac5aafb338ab3c511760ac6f5fddb9d9f21bab1d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
--------------------------------------------------------------------------------
module Language.Haskell.Stylish.Parse
( parseModule
) where
--------------------------------------------------------------------------------
import Control.Monad.Error (throwError)
import Data.Maybe (fromMaybe, listToMaybe)
import qualified Language.Haskell.Exts.Annotated as H
--------------------------------------------------------------------------------
import Language.Haskell.Stylish.Config
import Language.Haskell.Stylish.Step
--------------------------------------------------------------------------------
-- | Filter out lines which use CPP macros
unCpp :: String -> String
unCpp = unlines . go False . lines
where
go _ [] = []
go isMultiline (x : xs) =
let isCpp = isMultiline || listToMaybe x == Just '#'
nextMultiline = isCpp && not (null x) && last x == '\\'
in (if isCpp then "" else x) : go nextMultiline xs
--------------------------------------------------------------------------------
-- | If the given string is prefixed with an UTF-8 Byte Order Mark, drop it
-- because haskell-src-exts can't handle it.
dropBom :: String -> String
dropBom ('\xfeff' : str) = str
dropBom str = str
--------------------------------------------------------------------------------
-- | Abstraction over HSE's parsing
parseModule :: Extensions -> Maybe FilePath -> String -> Either String Module
parseModule extraExts mfp string = do
-- Determine the extensions: those specified in the file and the extra ones
let noBom = dropBom string
extraExts' = map H.classifyExtension extraExts
(lang, fileExts) = fromMaybe (Nothing, []) $ H.readExtensions noBom
exts = fileExts ++ extraExts'
-- Parsing options...
fp = fromMaybe "<unknown>" mfp
mode = H.defaultParseMode
{ H.extensions = exts
, H.fixities = Nothing
, H.baseLanguage = case lang of
Nothing -> H.baseLanguage H.defaultParseMode
Just l -> l
}
-- Preprocessing
noCpp =
if H.EnableExtension H.CPP `elem` exts then unCpp noBom else noBom
case H.parseModuleWithComments mode noCpp of
H.ParseOk md -> return md
err -> throwError $
"Language.Haskell.Stylish.Parse.parseModule: could not parse " ++
fp ++ ": " ++ show err
|
