From 49fd254f2588ec3b71fce50563415b1feea7c018 Mon Sep 17 00:00:00 2001
From: Aaron VonderHaar <gruen0aermel@gmail.com>
Date: Sun, 1 May 2022 14:54:53 -0700
Subject: [PATCH] Extract Gren.Format

---
 compiler/src/Gren/Format.hs |  9 +++++++++
 gren.cabal                  |  1 +
 terminal/src/Format.hs      | 10 ++++++++--
 3 files changed, 18 insertions(+), 2 deletions(-)
 create mode 100644 compiler/src/Gren/Format.hs

diff --git a/compiler/src/Gren/Format.hs b/compiler/src/Gren/Format.hs
new file mode 100644
index 00000000..ed94e8a6
--- /dev/null
+++ b/compiler/src/Gren/Format.hs
@@ -0,0 +1,9 @@
+module Gren.Format (toByteString) where
+
+import qualified AST.Source as Src
+import qualified Data.ByteString as BS
+
+toByteString :: Src.Module -> BS.ByteString
+toByteString =
+  -- TODO: implement actual formating
+  undefined
diff --git a/gren.cabal b/gren.cabal
index e28500e0..a5b94224 100644
--- a/gren.cabal
+++ b/gren.cabal
@@ -91,6 +91,7 @@ Common gren-common
         Gren.Constraint
         Gren.Docs
         Gren.Float
+        Gren.Format
         Gren.Interface
         Gren.Kernel
         Gren.Licenses
diff --git a/terminal/src/Format.hs b/terminal/src/Format.hs
index 3852e8c5..711f305e 100644
--- a/terminal/src/Format.hs
+++ b/terminal/src/Format.hs
@@ -12,7 +12,9 @@ import qualified Data.ByteString as BS
 import qualified Data.NonEmptyList as NE
 import qualified Directories as Dirs
 import qualified File
+import qualified Gren.Format as Format
 import qualified Gren.Outline as Outline
+import qualified Parse.Module as Parse
 import qualified Reporting
 import qualified Reporting.Doc as D
 import qualified Reporting.Exit as Exit
@@ -154,5 +156,9 @@ formatExistingFile path =
 
 formatByteString :: BS.ByteString -> BS.ByteString
 formatByteString original =
-  -- TODO: implement actual formating
-  original
+  case Parse.fromByteString Parse.Application original of
+    Left _ ->
+      -- TODO: report error
+      original
+    Right ast ->
+      Format.toByteString ast