nothing that some text munging and 'sed' can't fix

WORKSPACE

@@ -94,9 +94,9 @@ stack_snapshot(
         "hspec",
         "hspec-core",
         "hspec-expectations",
-        "proto-lens-jsonpb",
         "lens",
         "lingo",
+        "neat-interpolation",
         "network",
         "network-uri",
         "optparse-applicative",
@@ -109,6 +109,7 @@ stack_snapshot(
         "prettyprinter-ansi-terminal",
         "process",
         "proto-lens",
+        "proto-lens-jsonpb",
         "proto-lens-runtime",
         "raw-strings-qq",
         "recursion-schemes",

semantic-ast/BUILD.bazel

@@ -56,8 +56,11 @@ haskell_binary(
         ":semantic-ast",
         "//:base",
         "//:filepath",
+        "//:process",
         "//:template-haskell",
+        "//:text",
         "@stackage//:directory",
+        "@stackage//:neat-interpolation",
         "@stackage//:optparse-generic",
         "@tree-sitter-json//:tree-sitter-json",
     ],

semantic-ast/app/Main.hs

@@ -1,28 +1,77 @@
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE TypeApplications #-}
 
 module Main (main) where
 
 import AST.GenerateSyntax
+import Data.Maybe
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Text.IO as T
 import GHC.Generics (Generic)
 import Language.Haskell.TH
+import NeatInterpolation
 import qualified Options.Generic as Opt
 import System.Directory
+import System.IO
+import System.Process
 import qualified TreeSitter.JSON as JSON (tree_sitter_json)
 
 data Config = Config
-  { language :: String,
+  { language :: Text,
     path :: FilePath
   }
   deriving (Show, Generic)
 
 instance Opt.ParseRecord Config
 
+header :: Text
+header =
+  [trimming|
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DeriveTraversable #-}
+{-# LANGUAGE DerivingStrategies #-}
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE KindSignatures #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE QuantifiedConstraints #-}
+{-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE UndecidableInstances #-}
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
+|]
+
 main :: IO ()
 main = do
-  args <- Opt.getRecord "generate-ast"
-  print @Config args
-  absolute <- makeAbsolute (path args)
+  Config language path <- Opt.getRecord "generate-ast"
+  absolute <- makeAbsolute path
   decls <- runQ (astDeclarationsRelative JSON.tree_sitter_json absolute)
-  putStrLn (pprint decls)
+
+  let modheader =
+        [trimming| module Language.$language.AST (module Language.$language.AST) where
+              -- Language definition for $language, enerated by ast-generate. Do not edit!
+              import Prelude ()
+                      |]
+
+  let programText = T.unlines [header, modheader, T.pack (pprint decls)]
+  hasOrmolu <- findExecutable "ormolu"
+  if isNothing hasOrmolu
+    then T.putStrLn programText
+    else do
+      (path, tf) <- openTempFile "/tmp" "generated.hs"
+      print path
+      T.hPutStrLn tf programText
+      hClose tf
+      callProcess "sed" ["-i", "-e", "s/AST.Traversable1.Class.Traversable1 someConstraint/(AST.Traversable1.Class.Traversable1 someConstraint)/g", path]
+      callProcess "ormolu" ["--mode", "inplace", path]
+      readFile path >>= putStrLn

stack-snapshot.yaml

@@ -8,6 +8,7 @@ packages:
   - fused-effects-readline-0.1.0.0
   - semilattices-0.0.0.4
   - haskeline-0.8.0.0
+  - Interpolation-0.3.0
   - tree-sitter-0.9.0.2
   - unliftio-core-0.2.0.1
   - lingo-0.5.0.1