made it so date is in the metadata instead of the filename

app/Main.hs

@@ -11,10 +11,6 @@ module Main where
 
 import Control.Monad (forM)
 import Data.List (sortOn)
-import Data.Text (Text)
-import Data.Time (UTCTime, defaultTimeLocale, formatTime, parseTimeM)
-import Deriving.Aeson
-import Deriving.Aeson.Stock (PrefixedSnake)
 import Development.Shake (Action, Rules, (|%>), (~>), (%>))
 import Development.Shake.FilePath ((</>))
 import qualified Data.HashMap.Strict as HM
@@ -23,6 +19,7 @@ import qualified Data.Text as T
 import qualified Development.Shake as Shake
 import qualified Development.Shake.FilePath as Shake
 import Config
+import Types
 import Utilities
 import Templates
 -- target = thing we want
@@ -59,7 +56,7 @@ buildRules = do
   home
   assets
   pages
-  posts
+  postsRule
   rss
 
 -- make a rule of the pattern outputDir/asset_name which copes from outputDir/../pages
@@ -69,31 +66,18 @@ assets = map (outputDir </>) assetGlobs |%> \target -> do
   Shake.copyFileChanged src target
   Shake.putInfo $ "Copied " <> target <> " from " <> src
 
-data Page = Page {pageTitle :: Text, pageContent :: Text}
-  deriving (Show, Generic)
-  deriving (ToJSON) via PrefixedSnake "page" Page
 
 pages :: Rules ()
 pages = map indexHtmlOutputPath pagePaths |%> \target -> do
   let src = indexHtmlSourcePath target
   (meta, html) <- typstToHtml src
 
-  let page = Page (meta HM.! "title") html
+  let page = Page (postTitle meta) html
   applyTemplateAndWrite "default.html" page target
   Shake.putInfo $ "Built " <> target <> " from " <> src
 
-data Post = Post
-  { postTitle :: Text,
-    postAuthor :: Maybe Text,
-    postTags :: [Text],
-    postDate :: Maybe Text,
-    postContent :: Maybe Text,
-    postLink :: Maybe Text
-  } deriving (Show, Generic)
-    deriving (FromJSON, ToJSON) via PrefixedSnake "post" Post
-
-posts :: Rules ()
-posts = map indexHtmlOutputPath postGlobs |%> \target -> do
+postsRule :: Rules ()
+postsRule = map indexHtmlOutputPath postGlobs |%> \target -> do
   let src = indexHtmlSourcePath target
   post <- readPost src
   postHtml <- applyTemplate "post.html" post
@@ -125,17 +109,11 @@ rss = outputDir </> "index.xml" %> \target -> do
 
 readPost :: FilePath -> Action Post
 readPost postPath = do
-  date <- parseTimeM False defaultTimeLocale "%Y-%-m-%-d"
-    . take 10
-    . Shake.takeBaseName
-    $ postPath
-  let formattedDate =
-        T.pack $ formatTime @UTCTime defaultTimeLocale "%b %e, %Y" date
-
   (post, html) <- typstToHtml postPath
+  Shake.putInfo $ show post
   Shake.putInfo $ "Read " <> postPath
   return $ post
-    { postDate = Just formattedDate,
+    { 
       postContent = Just html,
       postLink = Just . T.pack $ "/" <> Shake.dropExtension postPath <> "/"
     }

app/Types.hs

@@ -0,0 +1,22 @@
+{-# LANGUAGE ApplicativeDo, DataKinds, DeriveGeneric #-}
+{-# LANGUAGE DerivingVia, TypeApplications #-}
+
+module Types where
+
+import Deriving.Aeson
+import Deriving.Aeson.Stock (PrefixedSnake)
+import Data.Text (Text)
+
+data Page = Page {pageTitle :: Text, pageContent :: Text}
+  deriving (Show, Generic)
+  deriving (ToJSON) via PrefixedSnake "page" Page
+
+data Post = Post
+  { postTitle :: Text,
+    postAuthor :: Maybe Text,
+    postTags :: [Text],
+    postDate :: Maybe Text,
+    postContent :: Maybe Text,
+    postLink :: Maybe Text
+  } deriving (Show, Generic)
+    deriving (FromJSON, ToJSON) via PrefixedSnake "post" Post

app/Utilities.hs

@@ -1,6 +1,7 @@
-{-# LANGUAGE ApplicativeDo, DataKinds, DeriveGeneric #-}
+{-# LANGUAGE ApplicativeDo, DataKinds, NamedFieldPuns #-}
 {-# LANGUAGE DerivingVia, LambdaCase, TypeApplications #-}
 module Utilities where
+
 import Data.Text (Text)
 import Development.Shake.FilePath ((<.>), (</>))
 import qualified Data.Text as T
@@ -11,6 +12,9 @@ import Config
 import Development.Shake (Action)
 import Text.Pandoc 
 import Data.Aeson as A
+import Data.Time (UTCTime(UTCTime), formatTime, defaultTimeLocale, parseTimeM)
+import Types
+import Data.Maybe (fromJust)
 
 indexHtmlOutputPath :: FilePath -> FilePath
 indexHtmlOutputPath srcPath =
@@ -23,14 +27,15 @@ indexHtmlSourcePath =
     . Shake.dropTrailingPathSeparator
     . Shake.dropFileName
 
-typstToHtml :: FromJSON a => FilePath -> Action (a, Text)
+typstToHtml :: FilePath -> Action (Post, Text)
 typstToHtml filePath = do
   content <- Shake.readFile' filePath
   Shake.quietly . Shake.traced "Typst to HTML" $ do
     doc@(Pandoc meta _) <- runPandoc . Pandoc.readTypst readerOptions . T.pack $ content
     meta' <- fromMeta meta
+    let dateTransformedMeta = dateTransform meta'
     html <- runPandoc . Pandoc.writeHtml5String writerOptions $ doc
-    return (meta', html)
+    return (fromJust dateTransformedMeta, html)
   where
     readerOptions =
       Pandoc.def {Pandoc.readerExtensions = Pandoc.pandocExtensions}
@@ -54,3 +59,11 @@ typstToHtml filePath = do
     runPandoc action =
           Pandoc.runIO (Pandoc.setVerbosity Pandoc.ERROR >> action)
             >>= either (fail . show) return
+    dateTransform post@(Post{postDate}) = do
+        postDate' <- dateStrTransform $ T.unpack $ fromJust postDate
+        Just post {
+            postDate = Just postDate'
+        }
+    dateStrTransform date = do 
+        date' <- parseTimeM False defaultTimeLocale "%Y-%-m-%-d" date
+        Just $ T.pack $ formatTime @UTCTime defaultTimeLocale "%b %e, %Y" date'

psb.cabal

@@ -62,7 +62,7 @@ executable psb
     main-is:          Main.hs
 
     -- Modules included in this executable, other than Main.
-    other-modules: Config Utilities Templates
+    other-modules: Config Utilities Templates Types
 
     -- LANGUAGE extensions used by modules in this package.
     -- other-extensions: