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
67
68
69
70
71
72
73
|
{- Copyright © 2015 Benjamin Barenblat
This program is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>. -}
{-# LANGUAGE LambdaCase #-}
module Main where
import Data.Data (Data)
import Data.Typeable (Typeable)
import GHC.Generics (Generic)
import Data.Functor ((<$>))
import System.Environment (getArgs)
import System.Exit (exitFailure)
import Fragment (parseFragments)
import Tangle (tangle)
import Weave (weave)
data Operation = Tangle | Weave
deriving (Eq, Show, Data, Typeable, Generic, Read)
parseOp :: String -> Maybe Operation
parseOp "tangle" = Just Tangle
parseOp "weave" = Just Weave
parseOp _ = Nothing
data Configuration = Configuration Operation (Maybe FilePath)
deriving (Eq, Show, Data, Typeable, Generic)
main :: IO ()
main = do
processArguments <$> getArgs >>= \case
Nothing -> usage >> exitFailure
Just (Configuration op file) -> do
let pathString = case file of Nothing -> "<stdin>"
Just path -> path
input <- case file of Nothing -> getContents
Just path -> readFile path
case doOperation op (pathString, input) of
Left err -> putStrLn err >> exitFailure
Right result -> putStr result
doOperation :: Operation -> (FilePath, String) -> Either String String
doOperation op (path, input) = do
parsed <- parseFragments path input
case op of
Tangle -> tangle parsed
Weave -> weave parsed
processArguments :: [String] -> Maybe Configuration
processArguments [opString] =
case parseOp opString of
Just op -> Just $ Configuration op Nothing
Nothing -> Nothing
processArguments [opString, file] =
case parseOp opString of
Just op -> Just $ Configuration op (Just file)
Nothing -> Nothing
processArguments _ = Nothing
usage :: IO ()
usage = putStrLn "usage: lyt (tangle|weave) [file]"
|
