Add Process.nullStream (#82)

* rename number of `optparse` example

* add `Process.setStdin` and `Process.setStderr`

* add `Process.nullStream`

* create example for `Process.nullStream`

* bump `base` upper bound

examples/33-null-stream.hell

@@ -0,0 +1,3 @@
+main = do
+  -- discard stdout
+  Process.runProcess_ $ Process.setStdout Process.nullStream $ Process.proc "ls" []

hell.cabal

@@ -22,7 +22,7 @@ executable hell
       QuickCheck
     , aeson
     , async
-    , base >=4.17.2.1 && <4.18
+    , base >=4.17.2.1 && <4.19
     , bytestring
     , constraints
     , containers

src/Hell.hs

@@ -1653,7 +1653,10 @@ polyLits =
                  -- Process
                  "Process.runProcess" runProcess :: forall a b c. ProcessConfig a b c -> IO ExitCode
                  "Process.runProcess_" runProcess_ :: forall a b c. ProcessConfig a b c -> IO ()
+                 "Process.setStdin" setStdin :: forall stdin stdin' stdout stderr. StreamSpec 'STInput stdin' -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin' stdout stderr
                  "Process.setStdout" setStdout :: forall stdin stdout stdout' stderr. StreamSpec 'STOutput stdout' -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout' stderr
+                 "Process.setStderr" setStderr :: forall stdin stdout stderr stderr'. StreamSpec 'STOutput stderr' -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr'
+                 "Process.nullStream" Process.nullStream :: forall (a :: StreamType). StreamSpec a ()
                  "Process.useHandleClose" useHandleClose :: forall (a :: StreamType). IO.Handle -> StreamSpec a ()
                  "Process.useHandleOpen" useHandleOpen :: forall (a :: StreamType). IO.Handle -> StreamSpec a ()
                  "Process.setWorkingDir" process_setWorkingDir :: forall a b c. Text -> ProcessConfig a b c -> ProcessConfig a b c