Incorporate Python files formerly in separate repo

.gitignore

@@ -4,3 +4,4 @@ ptghci-engine.cabal
 tags
 log.txt
 ptghci_log.txt
+BUGS

ChangeLog.md

@@ -1,3 +1,3 @@
-# Changelog for ptghci-engine
+# Changelog for ptghci
 
 ## Unreleased changes

LICENSE

@@ -1,4 +1,5 @@
-Copyright Author name here (c) 2019
+Copyright Richard Warfield 2019
+Ghcid portions (c) Neil Mitchell 2014-2018
 
 All rights reserved.
 

README.md

@@ -7,8 +7,8 @@ ptghci is an interactive command shell for Haskell designed for high-productivit
 ## Installation
 
 ```
-stack install ptghci-engine
-pip install ptghci
+pip install -r requirements.txt
+stack install
 ```
 
 ## Usage

app/Main.hs

@@ -1,33 +1,51 @@
+{-# LANGUAGE LambdaCase #-}
 
 module Main where
 
 import Language.Haskell.PtGhci.Prelude
-import Language.Haskell.PtGhci.App
+import Language.Haskell.PtGhci.Engine
+import Language.Haskell.PtGhci.StartPy
 import Foreign.C.Types
+import System.IO (hFlush)
 import System.Environment
 import System.FilePath
 import System.Process
--- import Paths_ptghci_engine
-
--- foreign import ccall "run_python_interpreter" runPythonIntepreter :: IO CInt
-
-main = runApp
--- do
---   dataDir <- getDataDir
---   putStrLn dataDir
---   pythonPath <- lookupEnv "PYTHONPATH"
---   let pythonBase = dataDir </> "pybits"
---       pyMain = pythonBase </> "main.py"
---   case pythonPath of
---     Nothing -> setEnv "PYTHONPATH" pythonBase
---     Just path -> setEnv "PYTHONPATH" (path ++ ":" ++ pythonBase)
---   -- runPythonIntepreter
---   createProcess (proc "python3" [pyMain]) {
---     cwd = Nothing,
---     env = Nothing,
---     std_in = Inherit,
---     std_out = Inherit,
---     close_fds = False,
---     create_group = False,
---     delegate_ctlc = True }
---   forever (return ())
+
+main :: IO ()
+main = do
+  sockets <- setupSockets
+
+  -- Check if we are running in "engine mode" -- if so we should not start the
+  -- Python interpreter, but should print the ZeroMQ sockets we are using to
+  -- stdout
+  lookupEnv "PTGHCI_ENGINE_MODE" >>= \case
+    Just _ -> runEngineMode sockets
+    Nothing -> runPythonInProc sockets
+
+
+-- | The normal way we run -- Python interpreter runs prompt-toolkit loop
+-- in-process.
+runPythonInProc :: Sockets -> IO ()
+runPythonInProc sockets = do
+  sockAddrs <- socketEndpoints sockets
+
+  (appThread, quitApp) <- runApp sockets
+  withAsync (startPythonApp sockAddrs) $ \pyThread -> do
+    res <- waitEither pyThread appThread
+    case res of
+      Left () -> quitApp
+      Right () -> return ()
+
+-- | Don't run the Python intepreter; just start the engine and listen for a
+-- connection from an external Python process.  Used for testing.  In the
+-- future may be used for Jupyter notebook connections.
+runEngineMode :: Sockets -> IO ()
+runEngineMode sockets = do
+  sockAddrs <- socketEndpoints sockets
+
+  -- Print the socket addresses so Python knows how to connect
+  print sockAddrs >> hFlush stdout
+
+  (appThread, quitApp) <- runApp sockets
+  wait appThread `finally` quitApp
+