blob: 4dcaa536a4915afaea5cc0667a6c0bd02f1cdf47 (
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
|
{-# LANGUAGE OverloadedStrings #-}
-- |
module Paths where
import Data.Text (Text)
import qualified Data.Text as T
import Text.Regex.TDFA
import Util (PrettyPrint (prettyprint))
-- | a normalised path: a number of "upwards" steps, and
-- a path without any . or .. in it
data RelPath = Path Int Text (Maybe Text)
deriving (Show, Eq, Ord)
-- | horrible regex parsing for filepaths that is hopefully kinda safe
parsePath :: Text -> Maybe RelPath
parsePath text =
if rest =~ ("^([^/]*[^\\./]/)*[^/]*[^\\./]$" :: Text) :: Bool
then Just $ Path up path fragment
else Nothing
where
(_, prefix, rest, _) =
text =~ ("^((\\.|\\.\\.)/)*" :: Text) :: (Text, Text, Text, [Text])
-- how many steps upwards in the tree?
up = length . filter (".." ==) . T.splitOn "/" $ prefix
parts = T.splitOn "#" rest
path = head parts
fragment = if length parts >= 2
then Just $ T.concat $ tail parts -- TODO!
else Nothing
instance PrettyPrint RelPath where
prettyprint (Path up rest _) = ups <> rest
where ups = T.concat $ replicate up "../"
normalise :: RelPath -> FilePath
normalise (Path 0 path _) = T.unpack path
normalize _ = error "not implemented yet"
|
