From e7e767c007bd48f2582e06fc6b488f1da1641edc Mon Sep 17 00:00:00 2001
From: "Niels G. W. Serup" <ngws@metanohi.name>
Date: Mon, 23 Sep 2024 22:11:54 +0200
Subject: [PATCH] Clean up and move things around

---
 byg/byg.cabal                           |  15 +--
 byg/src/ComputationM.hs                 |  95 ------------------
 byg/src/Dependency.hs                   | 128 ++++++------------------
 byg/src/DependencyGenerator.hs          | 115 +++++++++++++++++++++
 byg/src/Evaluation/Function.hs          |   8 ++
 byg/src/Evaluation/FunctionIO.hs        |   8 ++
 byg/src/FunctionImplementations/IO.hs   |  37 -------
 byg/src/FunctionImplementations/Pure.hs |  19 ----
 byg/src/Functions.hs                    |  32 ------
 byg/src/Generator.hs                    |  24 -----
 byg/src/Main.hs                         |  12 +--
 byg/src/SiteGenerator.hs                |  22 ++++
 byg/src/Sources.hs                      |  18 ----
 byg/src/Types.hs                        |  71 +++----------
 byg/src/Types/Function.hs               |  10 ++
 byg/src/Types/FunctionIO.hs             |  12 +++
 byg/src/Types/Token.hs                  |  15 +++
 byg/src/Types/Value.hs                  |  21 ++++
 byg/src/Types/Values.hs                 |  17 ++++
 19 files changed, 286 insertions(+), 393 deletions(-)
 delete mode 100644 byg/src/ComputationM.hs
 create mode 100644 byg/src/DependencyGenerator.hs
 create mode 100644 byg/src/Evaluation/Function.hs
 create mode 100644 byg/src/Evaluation/FunctionIO.hs
 delete mode 100644 byg/src/FunctionImplementations/IO.hs
 delete mode 100644 byg/src/FunctionImplementations/Pure.hs
 delete mode 100644 byg/src/Functions.hs
 delete mode 100644 byg/src/Generator.hs
 create mode 100644 byg/src/SiteGenerator.hs
 delete mode 100644 byg/src/Sources.hs
 create mode 100644 byg/src/Types/Function.hs
 create mode 100644 byg/src/Types/FunctionIO.hs
 create mode 100644 byg/src/Types/Token.hs
 create mode 100644 byg/src/Types/Value.hs
 create mode 100644 byg/src/Types/Values.hs

diff --git a/byg/byg.cabal b/byg/byg.cabal
index dcee009..16b750d 100644
--- a/byg/byg.cabal
+++ b/byg/byg.cabal
@@ -17,14 +17,17 @@ library
     import: common
     hs-source-dirs: src
     exposed-modules:
+        Types.Token
+        Types.Values
+        Types.Value
+        Types.Function
+        Types.FunctionIO
         Types
-        Sources
-        FunctionImplementations.Pure
-        FunctionImplementations.IO
         Dependency
-        ComputationM
-        Functions
-        Generator
+        DependencyGenerator
+        Evaluation.Function
+        Evaluation.FunctionIO
+        SiteGenerator
     build-depends:
         base
       , mtl
diff --git a/byg/src/ComputationM.hs b/byg/src/ComputationM.hs
deleted file mode 100644
index 55a97fb..0000000
--- a/byg/src/ComputationM.hs
+++ /dev/null
@@ -1,95 +0,0 @@
-module ComputationM
-  ( ComputationM
-  , evalComputationM
-  , inject
-  -- , inject'
-  , mapComputationM
-  , mapComputationM_
-  , filterComputationM
-  , runFunction
-  , runFunctionIO
-  ) where
-
-import Types
-import Dependency
-
-import Control.Monad.State
-import Control.Monad.Writer
-import Language.Haskell.TH.Syntax
-
-newtype ComputationM' a = ComputationM { unComputationM :: WriterT [DependencyUntyped] (State Int) a }
-  deriving (Functor, Applicative, Monad, MonadState Int, MonadWriter [DependencyUntyped])
-
-type ComputationM a = ComputationM' (Token a)
-
-evalComputationM' :: Int -> ComputationM () -> ([DependencyUntyped], Int)
-evalComputationM' top m = runState (execWriterT (unComputationM m)) top
-
-evalComputationM :: ComputationM () -> [DependencyUntyped]
-evalComputationM m = fst (evalComputationM' 0 m)
-
-tellDep :: (Show a, Show b, Lift a, Lift b) => Dependency a b -> ComputationM' ()
-tellDep dep = tell [makeUntyped dep]
-
-genDependency' :: (Show u, Show a, Lift u, Lift a) => (Token a -> ComputationM' (Dependency u a)) -> ComputationM a
-genDependency' f = do
-  top <- get
-  let top' = top + 1
-      target = Token top'
-  put top'
-  result <- f target
-  tellDep result
-  pure target
-
-genDependency :: (Show u, Show a, Lift u, Lift a) => (Token a -> Dependency u a) -> ComputationM a
-genDependency f = genDependency' (pure . f)
-
--- inject :: (Show a, Lift a) => a -> ComputationM a
--- inject x = genDependency (Dependency NoToken (Inject x))
-
-inject :: (Show a, Lift a, Valuable a) => a -> ComputationM a
-inject x = genDependency (Dependency NoToken (Inject (toValue x)))
-
--- inject' :: ImageConversionSettings -> ComputationM ImageConversionSettings
--- -- inject' x = genDependency (Dependency NoToken (InjectImageConversionSettings x))
--- inject' x = genDependency (Dependency NoToken (Inject WImageConversionSettings x))
-
-getListElem :: (Show a, Lift a) => Token [a] -> ComputationM a
-getListElem outer = genDependency (Dependency outer GetListElem)
-
-setListElem :: (Show a, Lift a) => Token a -> Token [a] -> ComputationM ()
-setListElem a outer = do
-  tellDep (Dependency a SetListElem outer)
-  pure NoToken
-
--- runFunction :: (Show a, Show b, Lift a, Lift b, IsFunction f a b) => f -> Token a -> ComputationM b
--- runFunction f input = genDependency (Dependency input (Function f))
-
--- runFunctionIO :: (Show a, Show b, Lift a, Lift b, IsFunctionIO f a b) => f -> Token a -> ComputationM b
--- runFunctionIO f input = genDependency (Dependency input (FunctionIO f))
-
-runFunction :: (Show a, Show b, Lift a, Lift b) => Function -> Token a -> ComputationM b
-runFunction f input = genDependency (Dependency input (Function f))
-
-runFunctionIO :: (Show a, Show b, Lift a, Lift b) => FunctionIO -> Token a -> ComputationM b
-runFunctionIO f input = genDependency (Dependency input (FunctionIO f))
-
-mapComputationM :: (Show a, Show b, Lift a, Lift b) => (Token a -> ComputationM b) -> Token [a] -> ComputationM [b]
-mapComputationM f input = genDependency' $ \target -> do
-  top <- get
-  let (res, top') = evalComputationM' top $ do
-        inp <- getListElem input
-        outp <- f inp
-        setListElem outp target
-  put top'
-  pure (Dependency input (MapComp res) target)
-
-mapComputationM_ :: (Show a, Lift a) => (Token a -> ComputationM ()) -> Token [a] -> ComputationM ()
-mapComputationM_ f input = do
-  _ <- mapComputationM f input
-  pure NoToken
-
-filterComputationM :: (Show a, Lift a) => (Token a -> ComputationM Bool) -> Token [a] -> ComputationM [a]
-filterComputationM f input = do
-  conds <- mapComputationM f input
-  genDependency (Dependency (TupleToken input conds) FilterComp)
diff --git a/byg/src/Dependency.hs b/byg/src/Dependency.hs
index 199cd72..2543067 100644
--- a/byg/src/Dependency.hs
+++ b/byg/src/Dependency.hs
@@ -1,112 +1,42 @@
-{-# LANGUAGE GADTs #-}
 module Dependency
-  ( TypedRun(..)
+  ( Action(..)
+  , UToken(..)
   , Dependency(..)
-  , Token(..)
-  , DependencyUntyped
-  , makeUntyped
-  , tupleTokens
-  , zipTokens
+  , makeDependency
   ) where
 
-import Types
+import Types.Token (Token(..))
+import Types.Value (Value)
+import Types.Function (Function)
+import Types.FunctionIO (FunctionIO)
 
--- import Unsafe.Coerce (unsafeCoerce)
-import Language.Haskell.TH.Syntax
+import Language.Haskell.TH.Syntax (Lift)
 
--- data TypedRun a b where
---   Function :: IsFunctionId f => f -> TypedRun a b
---   FunctionIO :: IsFunctionIOId f => f -> TypedRun a b
---   Function :: IsFunction f a b => f -> TypedRun a b
---   FunctionIO :: IsFunctionIO f a b => f -> TypedRun a b
---   Inject :: Lift b => b -> TypedRun () b
---   GetListElem :: TypedRun [b] b
---   SetListElem :: TypedRun a [a]
---   MapComp :: [DependencyUntyped] -> TypedRun [a] [b]
---   FilterComp :: TypedRun ([a], [Bool]) [a]
-
--- deriving instance (Show a, Show b) => Show (TypedRun a b)
--- deriving instance (Lift a, Lift b) => Lift (TypedRun a b)
-
--- data TypedRun where
---   -- Function :: IsFunctionId f => f -> TypedRun
---   -- FunctionIO :: IsFunctionIOId f => f -> TypedRun
---   Function :: Function -> TypedRun
---   FunctionIO :: FunctionIO -> TypedRun
---   -- Inject :: (Show b, Lift b) => b -> TypedRun
---   -- InjectString :: String -> TypedRun
---   -- InjectImageConversionSettings :: ImageConversionSettings -> TypedRun
---   -- Inject :: (Show a, Lift a, Witness w a) => w -> a -> TypedRun
---   Inject :: Value -> TypedRun
---   GetListElem :: TypedRun
---   SetListElem :: TypedRun
---   MapComp :: [DependencyUntyped] -> TypedRun
---   FilterComp :: TypedRun
-
--- deriving instance Show TypedRun
--- deriving instance Lift TypedRun
-
-data TypedRun = Function Function
-              | FunctionIO FunctionIO
-              | Inject Value
-              | GetListElem
-              | SetListElem
-              | MapComp [DependencyUntyped]
-              | FilterComp
+data Action = Function Function
+            | FunctionIO FunctionIO
+            | Inject Value
+            | MapComp [Dependency]
+            | FilterComp
+            | GetListElem
+            | SetListElem
   deriving (Show, Lift)
 
-data Token a where
-  Token :: Int -> Token a
-  TupleToken :: Token a -> Token b -> Token (a, b)
-  ZipToken :: Token [a] -> Token [b] -> Token [(a, b)]
-  NoToken :: Token ()
-
-deriving instance Show (Token a)
-deriving instance Lift (Token a)
-
-tupleTokens :: (Show a, Show b) => Token a -> Token b -> Token (a, b)
-tupleTokens = TupleToken
-
-zipTokens :: (Show a, Show b) => Token [a] -> Token [b] -> Token [(a, b)]
-zipTokens = ZipToken
-
--- data Dependency a b = Dependency (Token a) (TypedRun a b) (Token b)
---   deriving (Show)
-
-data Dependency a b = Dependency (Token a) TypedRun (Token b)
-  deriving (Show)
-
-deriving instance (Lift a, Lift b) => Lift (Dependency a b)
-
--- type DependencyUntyped = Dependency () ()
-
--- makeUntyped :: (Show a, Show b, Lift a, Lift b) => Dependency a b -> DependencyUntyped
--- makeUntyped dep = unsafeCoerce dep
-
-data TokenUntyped = UToken Int
-                  | UTupleToken TokenUntyped TokenUntyped
-                  | UZipToken TokenUntyped TokenUntyped
-                  | UNoToken
+data UToken = UToken Int
+            | UTupleToken UToken UToken
+            | UZipToken UToken UToken
+            | UNoToken
   deriving (Show, Lift)
 
-makeUntypedToken :: Token a -> TokenUntyped
-makeUntypedToken = \case
+data Dependency = Dependency UToken Action UToken
+  deriving (Show, Lift)
+
+makeDependency :: (Show a, Show b, Lift a, Lift b) => Token a -> Action -> Token b -> Dependency
+makeDependency a action b = Dependency (makeUToken a) action (makeUToken b)
+
+makeUToken :: Token a -> UToken
+makeUToken = \case
   Token i -> UToken i
-  TupleToken a b -> UTupleToken (makeUntypedToken a) (makeUntypedToken b)
-  ZipToken a b -> UZipToken (makeUntypedToken a) (makeUntypedToken b)
+  TupleToken a b -> UTupleToken (makeUToken a) (makeUToken b)
+  ZipToken a b -> UZipToken (makeUToken a) (makeUToken b)
   NoToken -> UNoToken
 
--- data DependencyUntyped where
---   DependencyUntyped :: TokenUntyped -> TypedRun -> TokenUntyped -> String -> DependencyUntyped
-
-data DependencyUntyped = DependencyUntyped TokenUntyped TypedRun TokenUntyped
-  deriving (Show, Lift)
-
--- instance Show DependencyUntyped--  where
---   -- show (DependencyUntyped _ _ _ s) = s
-
--- instance Lift DependencyUntyped
-
-makeUntyped :: (Show a, Show b, Lift a, Lift b) => Dependency a b -> DependencyUntyped
-makeUntyped (Dependency ta tr tb) =
-  DependencyUntyped (makeUntypedToken ta) tr (makeUntypedToken tb)
diff --git a/byg/src/DependencyGenerator.hs b/byg/src/DependencyGenerator.hs
new file mode 100644
index 0000000..a65bf2e
--- /dev/null
+++ b/byg/src/DependencyGenerator.hs
@@ -0,0 +1,115 @@
+module DependencyGenerator
+  ( DepGenM
+  , evalDepGenM
+  , inject
+  , runFunction
+  , runFunctionIO
+  , mapDepGenM
+  , mapDepGenM_
+  , filterDepGenM
+
+  , isImageFilename
+  , convertedImageFilename
+  , listDirectory
+  , readTemplate
+  , convertImage
+  , saveFile
+  , runPandoc
+  ) where
+
+import Types.Token (Token(..))
+import Types.Values
+import Types.Value (Valuable(..))
+import Types.Function (Function(..))
+import Types.FunctionIO (FunctionIO(..))
+import Dependency (Action(..), Dependency, makeDependency)
+
+import Control.Monad.State (MonadState, State, runState, put, get)
+import Control.Monad.Writer (MonadWriter, WriterT, execWriterT, tell)
+import Language.Haskell.TH.Syntax (Lift)
+
+newtype DepGenM' a = DepGenM { unDepGenM :: WriterT [Dependency] (State Int) a }
+  deriving (Functor, Applicative, Monad, MonadState Int, MonadWriter [Dependency])
+
+type DepGenM a = DepGenM' (Token a)
+
+evalDepGenM' :: Int -> DepGenM () -> ([Dependency], Int)
+evalDepGenM' top m = runState (execWriterT (unDepGenM m)) top
+
+evalDepGenM :: DepGenM () -> [Dependency]
+evalDepGenM m = fst (evalDepGenM' 0 m)
+
+tellDep :: Dependency -> DepGenM' ()
+tellDep dep = tell [dep]
+
+genDependencyM :: (Show a, Lift a) => (Token a -> DepGenM' Dependency) -> DepGenM a
+genDependencyM f = do
+  top <- get
+  let top' = top + 1
+      target = Token top'
+  put top'
+  result <- f target
+  tellDep result
+  pure target
+
+genDependency :: (Show a, Lift a) => (Token a -> Dependency) -> DepGenM a
+genDependency f = genDependencyM (pure . f)
+
+inject :: (Show a, Lift a, Valuable a) => a -> DepGenM a
+inject x = genDependency (makeDependency NoToken (Inject (toValue x)))
+
+getListElem :: (Show a, Lift a) => Token [a] -> DepGenM a
+getListElem outer = genDependency (makeDependency outer GetListElem)
+
+setListElem :: (Show a, Lift a) => Token a -> Token [a] -> DepGenM ()
+setListElem a outer = do
+  tellDep (makeDependency a SetListElem outer)
+  pure NoToken
+
+runFunction :: (Show a, Show b, Lift a, Lift b) => Function -> Token a -> DepGenM b
+runFunction f input = genDependency (makeDependency input (Function f))
+
+runFunctionIO :: (Show a, Show b, Lift a, Lift b) => FunctionIO -> Token a -> DepGenM b
+runFunctionIO f input = genDependency (makeDependency input (FunctionIO f))
+
+mapDepGenM :: (Show a, Show b, Lift a, Lift b) => (Token a -> DepGenM b) -> Token [a] -> DepGenM [b]
+mapDepGenM f input = genDependencyM $ \target -> do
+  top <- get
+  let (res, top') = evalDepGenM' top $ do
+        inp <- getListElem input
+        outp <- f inp
+        setListElem outp target
+  put top'
+  pure (makeDependency input (MapComp res) target)
+
+mapDepGenM_ :: (Show a, Lift a) => (Token a -> DepGenM ()) -> Token [a] -> DepGenM ()
+mapDepGenM_ f input = do
+  _ <- mapDepGenM f input
+  pure NoToken
+
+filterDepGenM :: (Show a, Lift a) => (Token a -> DepGenM Bool) -> Token [a] -> DepGenM [a]
+filterDepGenM f input = do
+  conds <- mapDepGenM f input
+  genDependency (makeDependency (TupleToken input conds) FilterComp)
+
+
+isImageFilename :: Token FilePath -> DepGenM Bool
+isImageFilename = runFunction IsImageFilename
+
+convertedImageFilename :: Token FilePath -> DepGenM FilePath
+convertedImageFilename = runFunction ConvertedImageFilename
+
+listDirectory :: Token FilePath -> DepGenM [FilePath]
+listDirectory = runFunctionIO ListDirectory
+
+readTemplate :: Token FilePath -> DepGenM Template
+readTemplate = runFunctionIO ReadTemplate
+
+convertImage :: Token ((FilePath, FilePath), ImageConversionSettings) -> DepGenM ()
+convertImage = runFunctionIO ConvertImage
+
+saveFile :: Token (String, FilePath) -> DepGenM ()
+saveFile = runFunctionIO SaveFile
+
+runPandoc :: Token String -> DepGenM String
+runPandoc = runFunctionIO RunPandoc
diff --git a/byg/src/Evaluation/Function.hs b/byg/src/Evaluation/Function.hs
new file mode 100644
index 0000000..46a0a5c
--- /dev/null
+++ b/byg/src/Evaluation/Function.hs
@@ -0,0 +1,8 @@
+module Evaluation.Function
+  ( evalFunction
+  ) where
+
+import Types (Function(..))
+
+evalFunction :: Function -> a -> b
+evalFunction = undefined
diff --git a/byg/src/Evaluation/FunctionIO.hs b/byg/src/Evaluation/FunctionIO.hs
new file mode 100644
index 0000000..aaca9fb
--- /dev/null
+++ b/byg/src/Evaluation/FunctionIO.hs
@@ -0,0 +1,8 @@
+module Evaluation.FunctionIO
+  ( evalFunctionIO
+  ) where
+
+import Types (FunctionIO(..))
+
+evalFunctionIO :: FunctionIO -> a -> b
+evalFunctionIO = undefined
diff --git a/byg/src/FunctionImplementations/IO.hs b/byg/src/FunctionImplementations/IO.hs
deleted file mode 100644
index 7fd1467..0000000
--- a/byg/src/FunctionImplementations/IO.hs
+++ /dev/null
@@ -1,37 +0,0 @@
-module FunctionImplementations.IO
-  ( -- ListDirectory(..)
-  -- , ReadTemplate(..)
-  -- , ConvertImage(..)
-  -- , SaveFile(..)
-  -- , RunPandoc(..)
-  ) where
-
-import Sources()
-import Types
-
-import Language.Haskell.TH.Syntax
-
--- data ListDirectory = ListDirectory deriving (Show, Lift)
--- instance IsFunctionIOId ListDirectory
--- instance IsFunctionIO ListDirectory FilePath [FilePath] where
---   runFIO ListDirectory _path = undefined
-
--- data ReadTemplate = ReadTemplate deriving (Show, Lift)
--- instance IsFunctionIOId ReadTemplate
--- instance IsFunctionIO ReadTemplate FilePath Template where
---   runFIO ReadTemplate _path = undefined
-
--- data ConvertImage = ConvertImage deriving (Show, Lift)
--- instance IsFunctionIOId ConvertImage
--- instance IsFunctionIO ConvertImage ((FilePath, FilePath), ImageConversionSettings) () where
---   runFIO ConvertImage ((_, _), ResizeToWidth _)  = undefined
-
--- data SaveFile = SaveFile deriving (Show, Lift)
--- instance IsFunctionIOId SaveFile
--- instance IsFunctionIO SaveFile (String, FilePath) () where
---   runFIO SaveFile _source = undefined
-
--- data RunPandoc = RunPandoc deriving (Show, Lift)
--- instance IsFunctionIOId RunPandoc
--- instance IsFunctionIO RunPandoc String String where
---   runFIO RunPandoc _source = undefined
diff --git a/byg/src/FunctionImplementations/Pure.hs b/byg/src/FunctionImplementations/Pure.hs
deleted file mode 100644
index d06db90..0000000
--- a/byg/src/FunctionImplementations/Pure.hs
+++ /dev/null
@@ -1,19 +0,0 @@
-module FunctionImplementations.Pure
-  ( -- IsImageFilename(..)
-  -- , ConvertedImageFilename(..)
-  ) where
-
-import Sources()
-import Types
-
-import Language.Haskell.TH.Syntax
-
--- data IsImageFilename = IsImageFilename deriving (Show, Lift)
--- instance IsFunctionId IsImageFilename
--- instance IsFunction IsImageFilename FilePath Bool where
---   runF IsImageFilename _path = undefined
-
--- data ConvertedImageFilename = ConvertedImageFilename deriving (Show, Lift)
--- instance IsFunctionId ConvertedImageFilename
--- instance IsFunction ConvertedImageFilename FilePath FilePath where
---   runF ConvertedImageFilename _path = undefined
diff --git a/byg/src/Functions.hs b/byg/src/Functions.hs
deleted file mode 100644
index 55ef75e..0000000
--- a/byg/src/Functions.hs
+++ /dev/null
@@ -1,32 +0,0 @@
-{-# OPTIONS_GHC -Wno-missing-signatures #-}
-module Functions
-  ( isImageFilename
-  , convertedImageFilename
-  , listDirectory
-  , readTemplate
-  , convertImage
-  , saveFile
-  , runPandoc
-  ) where
-
-import FunctionImplementations.Pure
-import FunctionImplementations.IO
-import ComputationM
-import Types
-import Dependency
-
-isImageFilename :: Token FilePath -> ComputationM Bool
-isImageFilename = runFunction IsImageFilename
-convertedImageFilename :: Token FilePath -> ComputationM FilePath
-convertedImageFilename = runFunction ConvertedImageFilename
-
-listDirectory :: Token FilePath -> ComputationM [FilePath]
-listDirectory = runFunctionIO ListDirectory
-readTemplate :: Token FilePath -> ComputationM Template
-readTemplate = runFunctionIO ReadTemplate
-convertImage :: Token ((FilePath, FilePath), ImageConversionSettings) -> ComputationM ()
-convertImage = runFunctionIO ConvertImage
-saveFile :: Token (String, FilePath) -> ComputationM ()
-saveFile = runFunctionIO SaveFile
-runPandoc :: Token String -> ComputationM String
-runPandoc = runFunctionIO RunPandoc
diff --git a/byg/src/Generator.hs b/byg/src/Generator.hs
deleted file mode 100644
index ab4579e..0000000
--- a/byg/src/Generator.hs
+++ /dev/null
@@ -1,24 +0,0 @@
-module Generator (generate) where
-
-import Types
-import Dependency
-import ComputationM
-import Functions
-
-handleRecipeDir :: Token Template -> Token FilePath -> ComputationM ()
-handleRecipeDir _template dir = do
-  dirContents <- listDirectory dir
-  imageFilenames <- filterComputationM isImageFilename dirContents
-  convertedImageFilenames <- mapComputationM convertedImageFilename imageFilenames
-  flip mapComputationM_ (zipTokens imageFilenames convertedImageFilenames) $ \files -> do
-    settings <- inject $ ResizeToWidth 800
-    convertImage $ tupleTokens files settings
-
-generate :: ComputationM ()
-generate = do
-  templateFilename <- inject "template.html"
-  template <- readTemplate templateFilename
-  dir <- inject "retter"
-  dirContents <- listDirectory dir
-  mapComputationM_ (handleRecipeDir template) dirContents
-
diff --git a/byg/src/Main.hs b/byg/src/Main.hs
index 5a87e75..e0f4992 100644
--- a/byg/src/Main.hs
+++ b/byg/src/Main.hs
@@ -1,14 +1,14 @@
 {-# LANGUAGE TemplateHaskell #-}
 module Main where
 
-import Dependency
-import ComputationM
-import Generator
+import Types (Dependency)
+import DependencyGenerator (evalDepGenM)
+import SiteGenerator (generateSite)
 
-import Language.Haskell.TH.Syntax
+import Language.Haskell.TH.Syntax (lift)
 
-dependencies :: [DependencyUntyped]
-dependencies = $(lift (evalComputationM generate))
+dependencies :: [Dependency]
+dependencies = $(lift (evalDepGenM generateSite))
 
 main :: IO ()
 main = mapM_ print dependencies
diff --git a/byg/src/SiteGenerator.hs b/byg/src/SiteGenerator.hs
new file mode 100644
index 0000000..7a4962b
--- /dev/null
+++ b/byg/src/SiteGenerator.hs
@@ -0,0 +1,22 @@
+module SiteGenerator (generateSite) where
+
+import Types
+import DependencyGenerator
+
+handleRecipeDir :: Token Template -> Token FilePath -> DepGenM ()
+handleRecipeDir _template dir = do
+  dirContents <- listDirectory dir
+  imageFilenames <- filterDepGenM isImageFilename dirContents
+  convertedImageFilenames <- mapDepGenM convertedImageFilename imageFilenames
+  flip mapDepGenM_ (ZipToken imageFilenames convertedImageFilenames) $ \files -> do
+    settings <- inject $ ResizeToWidth 800
+    convertImage $ TupleToken files settings
+
+generateSite :: DepGenM ()
+generateSite = do
+  templateFilename <- inject "template.html"
+  template <- readTemplate templateFilename
+  dir <- inject "retter"
+  dirContents <- listDirectory dir
+  mapDepGenM_ (handleRecipeDir template) dirContents
+
diff --git a/byg/src/Sources.hs b/byg/src/Sources.hs
deleted file mode 100644
index ca4446f..0000000
--- a/byg/src/Sources.hs
+++ /dev/null
@@ -1,18 +0,0 @@
-{-# OPTIONS_GHC -Wno-orphans #-}
-module Sources where
-
--- TODO: Figure out if any of this is useful.
-
-import Types
-
--- data Source a where
---   Data :: a -> Source a
-
--- instance SourceState FilePath where
---   stateOfSource = undefined
-
--- instance SourceState ((FilePath, FilePath), ImageConversionSettings) where
---   stateOfSource = undefined
-
--- instance SourceState (String, FilePath) where
---   stateOfSource = undefined
diff --git a/byg/src/Types.hs b/byg/src/Types.hs
index 88a6875..62da03e 100644
--- a/byg/src/Types.hs
+++ b/byg/src/Types.hs
@@ -1,58 +1,15 @@
-{-# LANGUAGE FunctionalDependencies #-}
-module Types where
+module Types
+  ( module Types.Token
+  , module Types.Values
+  , module Types.Value
+  , module Types.Function
+  , module Types.FunctionIO
+  , Dependency
+  ) where
 
-import Data.ByteString (ByteString)
-import Language.Haskell.TH.Syntax
-
-data ImageConversionSettings = ResizeToWidth Int
-  deriving (Show, Lift)
-
-data TemplatePart = Literal String
-                  | KeyValue String
-  deriving (Show, Lift)
-
-data Template = Template [TemplatePart]
-  deriving (Show, Lift)
-
--- class (Show f, Lift f) => IsFunctionId f
-
--- class (IsFunctionId f, SourceState a) => IsFunction f a b | f -> a b where
---   runF :: f -> a -> b
-
--- class (Show f, Lift f) => IsFunctionIOId f
--- class (IsFunctionIOId f, SourceState a) => IsFunctionIO f a b | f -> a b where
---   runFIO :: f -> a -> IO b
-
--- class SourceState a where
---   stateOfSource :: a -> IO ByteString
-
-
-data Function = IsImageFilename
-              | ConvertedImageFilename
-  deriving (Show, Lift)
-
-data FunctionIO = ListDirectory
-                | ReadTemplate
-                | ConvertImage
-                | SaveFile
-                | RunPandoc
-  deriving (Show, Lift)
-
-
--- class (Show w, Lift w) => Witness w a | w -> a where
-
--- data WImageConversionSettings = WImageConversionSettings deriving (Show, Lift)
--- instance Witness WImageConversionSettings ImageConversionSettings
-
-data Value = ImageConversionSettings ImageConversionSettings
-           | String String
-  deriving (Show, Lift)
-
-class Valuable a where
-  toValue :: a -> Value
-
-instance Valuable ImageConversionSettings where
-  toValue = ImageConversionSettings
-
-instance Valuable String where
-  toValue = String
+import Types.Token
+import Types.Values
+import Types.Value
+import Types.Function
+import Types.FunctionIO
+import Dependency
diff --git a/byg/src/Types/Function.hs b/byg/src/Types/Function.hs
new file mode 100644
index 0000000..3b195f8
--- /dev/null
+++ b/byg/src/Types/Function.hs
@@ -0,0 +1,10 @@
+module Types.Function
+  ( Function(..)
+  ) where
+
+import Language.Haskell.TH.Syntax (Lift)
+
+data Function = IsImageFilename
+              | ConvertedImageFilename
+  deriving (Show, Lift)
+
diff --git a/byg/src/Types/FunctionIO.hs b/byg/src/Types/FunctionIO.hs
new file mode 100644
index 0000000..ef4c051
--- /dev/null
+++ b/byg/src/Types/FunctionIO.hs
@@ -0,0 +1,12 @@
+module Types.FunctionIO
+  ( FunctionIO(..)
+  ) where
+
+import Language.Haskell.TH.Syntax (Lift)
+
+data FunctionIO = ListDirectory
+                | ReadTemplate
+                | ConvertImage
+                | SaveFile
+                | RunPandoc
+  deriving (Show, Lift)
diff --git a/byg/src/Types/Token.hs b/byg/src/Types/Token.hs
new file mode 100644
index 0000000..f84f2bf
--- /dev/null
+++ b/byg/src/Types/Token.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE GADTs #-}
+module Types.Token
+  ( Token(..)
+  ) where
+
+import Language.Haskell.TH.Syntax (Lift)
+
+data Token a where
+  Token :: Int -> Token a
+  TupleToken :: Token a -> Token b -> Token (a, b)
+  ZipToken :: Token [a] -> Token [b] -> Token [(a, b)]
+  NoToken :: Token ()
+
+deriving instance Show (Token a)
+deriving instance Lift (Token a)
diff --git a/byg/src/Types/Value.hs b/byg/src/Types/Value.hs
new file mode 100644
index 0000000..95542d3
--- /dev/null
+++ b/byg/src/Types/Value.hs
@@ -0,0 +1,21 @@
+module Types.Value
+  ( Value(..)
+  , Valuable(..)
+  ) where
+
+import Types.Values
+
+import Language.Haskell.TH.Syntax (Lift)
+
+data Value = String String
+           | ImageConversionSettings ImageConversionSettings
+  deriving (Show, Lift)
+
+class Valuable a where
+  toValue :: a -> Value
+
+instance Valuable String where
+  toValue = String
+
+instance Valuable ImageConversionSettings where
+  toValue = ImageConversionSettings
diff --git a/byg/src/Types/Values.hs b/byg/src/Types/Values.hs
new file mode 100644
index 0000000..728b9e8
--- /dev/null
+++ b/byg/src/Types/Values.hs
@@ -0,0 +1,17 @@
+module Types.Values
+  ( ImageConversionSettings(..)
+  , TemplatePart(..)
+  , Template(..)
+  ) where
+
+import Language.Haskell.TH.Syntax (Lift)
+
+data ImageConversionSettings = ResizeToWidth Int
+  deriving (Show, Lift)
+
+data TemplatePart = Literal String
+                  | KeyValue String
+  deriving (Show, Lift)
+
+data Template = Template [TemplatePart]
+  deriving (Show, Lift)