Initial parsing working

.gitignore

@@ -0,0 +1 @@
+/.stack-work

app/Main.hs

@@ -1,6 +1,20 @@
 module Main where
 
-import Lib
+import System.Environment
+import System.Exit
+import Data.Foldable
+import Data.Either
+import Control.Monad
+
+import qualified Data.Text.IO as TIO
+
+import Plated.Parser
+import Plated.Template
 
 main :: IO ()
-main = someFunc
+main = do
+  filenames <- getArgs
+  templates <- traverse templateFromFile filenames
+  when (not . null $ lefts templates) $
+    print (lefts templates) >> exitFailure
+  traverse_ (processTemplate >=> TIO.putStr) (rights templates)

examples/templates/simple.md

@@ -0,0 +1,12 @@
+#!/bin/plated
+{{ value }}
+
+This is normal Text
+
+{{[[ $this | tr 'a-z' 'A-Z' ]]
+Testing and stuff
+}}
+
+more text
+
+{{ value }}{{ value }}

plated.cabal

@@ -15,8 +15,13 @@ cabal-version:       >=1.10
 
 library
   hs-source-dirs:      src
-  exposed-modules:     Lib
+  exposed-modules:     Plated.Template
+                     , Plated.Parser
+                     , Plated.Command
   build-depends:       base >= 4.7 && < 5
+                     , text
+                     , parsec
+                     , process
   default-language:    Haskell2010
 
 executable plated-exe
@@ -25,6 +30,7 @@ executable plated-exe
   ghc-options:         -threaded -rtsopts -with-rtsopts=-N
   build-depends:       base
                      , plated
+                     , text
   default-language:    Haskell2010
 
 test-suite plated-test

src/Lib.hs

@@ -1,6 +0,0 @@
-module Lib
-    ( someFunc
-    ) where
-
-someFunc :: IO ()
-someFunc = putStrLn "someFunc"

src/Plated/Command.hs

@@ -0,0 +1,17 @@
+module Plated.Command
+  ( Command(..)
+  , interpCommand
+  ) where
+
+import System.Process
+import qualified Data.Text as T
+
+data Command =
+  Command T.Text
+  deriving Show
+
+interpCommand :: Command -> IO T.Text
+interpCommand (Command cmd) = do
+  (_, out, _) <- readCreateProcessWithExitCode (shell $ T.unpack cmd) ""
+  return . T.pack $ out
+

src/Plated/Parser.hs

@@ -0,0 +1,60 @@
+{-# language OverloadedStrings #-}
+module Plated.Parser
+  ( templateFromFile
+  , interpolate
+  , shebang
+  ) where
+
+import Plated.Template
+import Plated.Command
+
+import Data.Text.IO as TIO
+import qualified Data.Text as T
+
+import Control.Applicative (liftA2)
+
+import Text.Parsec
+import Text.Parsec.Text
+
+
+infix 0 ?>
+(?>) :: String -> ParsecT s u m a -> ParsecT s u m a
+(?>) = flip (<?>)
+
+templateFromFile :: FilePath -> IO (Either ParseError (Template Directive))
+templateFromFile fname = do
+  file <- TIO.readFile fname
+  return $ runP templateParser () fname file
+
+templateParser :: Parser (Template Directive)
+templateParser = do
+  tmp <- template
+  optional shebang
+  eof
+  return tmp
+
+template :: Parser (Template Directive)
+template = Template <$> many (dir <|> txt)
+    where
+      dir = Right <$> directive
+      txt = Left . T.pack <$> many1 (notFollowedBy (string "{{") *> anyChar)
+
+shebang :: Parser String
+shebang = "she-bang" ?> liftA2 (++) (string "#!") (manyTill anyChar (char '\n'))
+
+directive :: Parser Directive
+directive = "Directive" ?> do
+  _ <- string "{{"
+  spaces
+  mCommand <- optionMaybe cmd
+  txt <- manyTill anyChar (string "}}")
+  return $ Directive mCommand (T.pack txt)
+
+cmd :: Parser Command
+cmd = do
+  _ <- string "[["
+  cmdString <- manyTill anyChar (string "]]")
+  return $ Command (T.pack cmdString)
+
+interpolate :: Template Directive -> T.Text
+interpolate = const "hi"

src/Plated/Template.hs

@@ -0,0 +1,22 @@
+module Plated.Template
+  ( Template(..)
+  , Directive(..)
+  , processTemplate
+  ) where
+
+import Plated.Command
+
+import qualified Data.Text as T
+
+data Template a =
+  Template [Either T.Text a]
+  deriving Show
+
+data Directive =
+  Directive (Maybe Command) T.Text
+  deriving Show
+
+processTemplate :: Template Directive -> T.Text
+processTemplate (Template elems) = foldMap (either id fromDirective) elems
+  where
+    fromDirective (Directive _ txt) = txt