{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-|
Module      : Language.Alloy.Internal.Call
Copyright   : (c) Marcellus Siegburg, 2019 - 2021
License     : MIT

This module provides the basic internal functionality to retrieve the raw
results from calling Alloy.
It provides data types and functions to interact with Alloy.
-}
module Language.Alloy.Internal.Call (
  CallAlloyConfig (maxInstances, noOverflow, timeout),
  defaultCallAlloyConfig,
  getRawInstances,
  getRawInstancesWith,
  ) where

import qualified Data.ByteString                  as BS (
  hGetLine,
  intercalate,
  stripPrefix,
  )
import qualified Data.ByteString.Char8            as BS (unlines)

import Control.Concurrent (
  threadDelay,
  )
import Control.Concurrent.Async (
  concurrently,
  mapConcurrently_,
  wait,
  withAsync
  )
import Control.Concurrent.Extra         (Lock, newLock, withLock)
import Control.Exception                (IOException, bracket, catch)
import Control.Monad                    (unless, when)
import Control.Monad.Extra              (whenJust)
import Data.ByteString                  (ByteString)
import Data.ByteString.Char8            (unpack)
import Data.IORef (
  IORef,
  atomicWriteIORef,
#ifdef mingw32_HOST_OS
  newIORef,
#endif
  readIORef,
  )
import Data.List                        (intercalate)
import Data.List.Split                  (splitOn)
import Data.Maybe                       (fromMaybe)
import System.Exit                      (ExitCode (..))
import System.FilePath
  (searchPathSeparator)
import System.IO (
#ifndef mingw32_HOST_OS
  BufferMode (..),
  hSetBuffering,
#endif
  Handle,
  hClose,
  hFlush,
  hIsEOF,
  hPutStr,
  hPutStrLn,
  stderr,
  )
import System.IO.Unsafe                 (unsafePerformIO)
import System.Process (
  CreateProcess (..), StdStream (..), ProcessHandle,
  cleanupProcess,
  createProcess, proc, terminateProcess, waitForProcess,
  )

import Language.Alloy.RessourceNames (
  className, classPackage,
  )
import Language.Alloy.Ressources (
  alloyJar,
  commonsCliJar,
  slf4jJar,
  )
import Paths_call_alloy                 (getDataDir)

{-|
Configuration for calling alloy. These are:

 * maximal number of instances to retrieve ('Nothing' for all)
 * whether to not overflow when calculating numbers within Alloy
 * an timeout after which to forcibly kill Alloy
   (retrieving only instances that were returned before killing the process)
-}
data CallAlloyConfig = CallAlloyConfig {
  -- | maximal number of instances to retrieve ('Nothing' for all)
  CallAlloyConfig -> Maybe Integer
maxInstances :: !(Maybe Integer),
  -- | whether to not overflow when calculating numbers within Alloy
  CallAlloyConfig -> Bool
noOverflow   :: !Bool,
  -- | the time in microseconds after which to forcibly kill Alloy
  --   ('Nothing' for never)
  CallAlloyConfig -> Maybe Int
timeout      :: !(Maybe Int)
  }

{-|
Default configuration for calling Alloy. Defaults to:

 * retrieve all instances
 * do not overflow
-}
defaultCallAlloyConfig :: CallAlloyConfig
defaultCallAlloyConfig :: CallAlloyConfig
defaultCallAlloyConfig = CallAlloyConfig {
  maxInstances :: Maybe Integer
maxInstances = Maybe Integer
forall a. Maybe a
Nothing,
  noOverflow :: Bool
noOverflow   = Bool
True,
  timeout :: Maybe Int
timeout      = Maybe Int
forall a. Maybe a
Nothing
  }

{-# NOINLINE outLock #-}
outLock :: Lock
outLock :: Lock
outLock = IO Lock -> Lock
forall a. IO a -> a
unsafePerformIO IO Lock
newLock

putOutLn :: String -> IO ()
putOutLn :: String -> IO ()
putOutLn = Lock -> IO () -> IO ()
forall a. Lock -> IO a -> IO a
withLock Lock
outLock (IO () -> IO ()) -> (String -> IO ()) -> String -> IO ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. String -> IO ()
putStrLn

putErrLn :: String -> IO ()
putErrLn :: String -> IO ()
putErrLn = Lock -> IO () -> IO ()
forall a. Lock -> IO a -> IO a
withLock Lock
outLock (IO () -> IO ()) -> (String -> IO ()) -> String -> IO ()
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Handle -> String -> IO ()
hPutStrLn Handle
stderr

{-|
This function may be used to get all raw model instances for a given Alloy
specification. It calls Alloy via a Java interface and splits the raw instance
answers before returning the resulting list of raw instances.
-}
getRawInstances
  :: Maybe Integer
  -- ^ How many instances to return; 'Nothing' for all.
  -> String
  -- ^ The Alloy specification which should be loaded.
  -> IO [ByteString]
getRawInstances :: Maybe Integer -> String -> IO [ByteString]
getRawInstances Maybe Integer
maxIs = CallAlloyConfig -> String -> IO [ByteString]
getRawInstancesWith CallAlloyConfig
defaultCallAlloyConfig {
  maxInstances :: Maybe Integer
maxInstances = Maybe Integer
maxIs
  }

{-|
Creates an Alloy process using the given config.
-}
callAlloyWith
  :: CallAlloyConfig
  -> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
callAlloyWith :: CallAlloyConfig
-> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
callAlloyWith CallAlloyConfig
config = do
  String
classPath <- IO String
getClassPath
  let callAlloy :: CreateProcess
callAlloy = String -> [String] -> CreateProcess
proc String
"java"
        ([String] -> CreateProcess) -> [String] -> CreateProcess
forall a b. (a -> b) -> a -> b
$ [String
"-cp", String
classPath, String
classPackage String -> String -> String
forall a. [a] -> [a] -> [a]
++ Char
'.' Char -> String -> String
forall a. a -> [a] -> [a]
: String
className,
           String
"-i", Integer -> String
forall a. Show a => a -> String
show (Integer -> String) -> Integer -> String
forall a b. (a -> b) -> a -> b
$ Integer -> Maybe Integer -> Integer
forall a. a -> Maybe a -> a
fromMaybe (-Integer
1) (Maybe Integer -> Integer) -> Maybe Integer -> Integer
forall a b. (a -> b) -> a -> b
$ CallAlloyConfig -> Maybe Integer
maxInstances CallAlloyConfig
config]
        [String] -> [String] -> [String]
forall a. [a] -> [a] -> [a]
++ [String
"-o" | Bool -> Bool
not (Bool -> Bool) -> Bool -> Bool
forall a b. (a -> b) -> a -> b
$ CallAlloyConfig -> Bool
noOverflow CallAlloyConfig
config]
  CreateProcess
-> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
createProcess CreateProcess
callAlloy {
    std_out :: StdStream
std_out = StdStream
CreatePipe,
    std_in :: StdStream
std_in  = StdStream
CreatePipe,
    std_err :: StdStream
std_err = StdStream
CreatePipe
  }

{-|
This function may be used to get all raw model instances for a given Alloy
specification. It calls Alloy via a Java interface and splits the raw instance
answers before returning the resulting list of raw instances.
Parameters are set using a 'CallAlloyConfig'.
-}
getRawInstancesWith
  :: CallAlloyConfig
  -- ^ The configuration to be used.
  -> String
  -- ^ The Alloy specification which should be loaded.
  -> IO [ByteString]
getRawInstancesWith :: CallAlloyConfig -> String -> IO [ByteString]
getRawInstancesWith CallAlloyConfig
config String
content
  = IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
-> ((Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
    -> IO ())
-> ((Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
    -> IO [ByteString])
-> IO [ByteString]
forall a b c. IO a -> (a -> IO b) -> (a -> IO c) -> IO c
bracket (CallAlloyConfig
-> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
callAlloyWith CallAlloyConfig
config) (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle) -> IO ()
cleanupProcess (((Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
  -> IO [ByteString])
 -> IO [ByteString])
-> ((Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
    -> IO [ByteString])
-> IO [ByteString]
forall a b. (a -> b) -> a -> b
$ \(Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
p -> do
  (Just Handle
hin, Just Handle
hout, Just Handle
herr, ProcessHandle
ph) <- (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
-> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
p
#ifndef mingw32_HOST_OS
  Handle -> BufferMode -> IO ()
hSetBuffering Handle
hin BufferMode
NoBuffering
  let abort :: Maybe a
abort = Maybe a
forall a. Maybe a
Nothing
#else
  abort <- Just <$> newIORef False
#endif
  let evaluateAlloy' :: IO ()
evaluateAlloy' = do
        Handle -> String -> IO ()
hPutStr Handle
hin String
content
        Handle -> IO ()
hFlush Handle
hin
        Handle -> IO ()
hClose Handle
hin
      evaluateAlloy :: IO ()
evaluateAlloy = IO () -> (IOException -> IO ()) -> IO ()
forall e a. Exception e => IO a -> (e -> IO a) -> IO a
catch IO ()
evaluateAlloy' ((IOException -> IO ()) -> IO ())
-> (IOException -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \IOException
e -> do
        let err :: String
err = IOException -> String
forall a. Show a => a -> String
show (IOException
e :: IOException)
            warn :: String
warn = String
"Maybe not complete instance was sent to Alloy "
            explain :: String
explain = String
"(Are timeouts set? Make sure they are not too small!): "
        String -> IO ()
putErrLn (String
"Warning: " String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
warn String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
explain String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
err)
  Handle
-> Handle
-> Handle
-> ProcessHandle
-> Maybe (IORef Bool)
-> Maybe Int
-> IO [ByteString]
-> IO [ByteString]
forall a.
Handle
-> Handle
-> Handle
-> ProcessHandle
-> Maybe (IORef Bool)
-> Maybe Int
-> IO a
-> IO a
withTimeout Handle
hin Handle
hout Handle
herr ProcessHandle
ph Maybe (IORef Bool)
forall a. Maybe a
abort (CallAlloyConfig -> Maybe Int
timeout CallAlloyConfig
config) (IO [ByteString] -> IO [ByteString])
-> IO [ByteString] -> IO [ByteString]
forall a b. (a -> b) -> a -> b
$ do
    ([ByteString]
out, [ByteString]
err) <- (([ByteString], [ByteString]), ()) -> ([ByteString], [ByteString])
forall a b. (a, b) -> a
fst ((([ByteString], [ByteString]), ())
 -> ([ByteString], [ByteString]))
-> IO (([ByteString], [ByteString]), ())
-> IO ([ByteString], [ByteString])
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> IO ([ByteString], [ByteString])
-> IO () -> IO (([ByteString], [ByteString]), ())
forall a b. IO a -> IO b -> IO (a, b)
concurrently
      (IO [ByteString]
-> IO [ByteString] -> IO ([ByteString], [ByteString])
forall a b. IO a -> IO b -> IO (a, b)
concurrently (Handle -> IO [ByteString]
getOutput Handle
hout) (Handle -> IO [ByteString]
getOutput Handle
herr))
      IO ()
evaluateAlloy
    Maybe (IORef Bool) -> ProcessHandle -> IO ()
printContentOnError Maybe (IORef Bool)
forall a. Maybe a
abort ProcessHandle
ph
    let err' :: [ByteString]
err' = [ByteString] -> [ByteString]
removeInfoLines [ByteString]
err
    Bool -> IO () -> IO ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
unless ([ByteString] -> Bool
forall a. [a] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [ByteString]
err') (IO () -> IO ()) -> IO () -> IO ()
forall a b. (a -> b) -> a -> b
$ String -> IO ()
forall a. String -> IO a
forall (m :: * -> *) a. MonadFail m => String -> m a
fail (String -> IO ()) -> String -> IO ()
forall a b. (a -> b) -> a -> b
$ ByteString -> String
unpack (ByteString -> String) -> ByteString -> String
forall a b. (a -> b) -> a -> b
$ [ByteString] -> ByteString
BS.unlines [ByteString]
err'
    [ByteString] -> IO [ByteString]
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return ([ByteString] -> IO [ByteString])
-> [ByteString] -> IO [ByteString]
forall a b. (a -> b) -> a -> b
$ ([ByteString] -> ByteString) -> [[ByteString]] -> [ByteString]
forall a b. (a -> b) -> [a] -> [b]
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap (ByteString -> [ByteString] -> ByteString
BS.intercalate ByteString
"\n")
      ([[ByteString]] -> [ByteString]) -> [[ByteString]] -> [ByteString]
forall a b. (a -> b) -> a -> b
$ ([ByteString] -> Bool) -> [[ByteString]] -> [[ByteString]]
forall {a}. (a -> Bool) -> [a] -> [a]
filterLast ((ByteString -> ByteString -> Bool
forall a. Eq a => a -> a -> Bool
/= ByteString
partialInstance) (ByteString -> Bool)
-> ([ByteString] -> ByteString) -> [ByteString] -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. [ByteString] -> ByteString
forall a. HasCallStack => [a] -> a
last)
      ([[ByteString]] -> [[ByteString]])
-> [[ByteString]] -> [[ByteString]]
forall a b. (a -> b) -> a -> b
$ Int -> [[ByteString]] -> [[ByteString]]
forall a. Int -> [a] -> [a]
drop Int
1 ([[ByteString]] -> [[ByteString]])
-> [[ByteString]] -> [[ByteString]]
forall a b. (a -> b) -> a -> b
$ [ByteString] -> [ByteString] -> [[ByteString]]
forall a. Eq a => [a] -> [a] -> [[a]]
splitOn [ByteString
begin] [ByteString]
out
  where
    begin :: ByteString
    begin :: ByteString
begin = ByteString
"---INSTANCE---"
    filterLast :: (a -> Bool) -> [a] -> [a]
filterLast a -> Bool
_ []     = []
    filterLast a -> Bool
p x :: [a]
x@[a
_]  = (a -> Bool) -> [a] -> [a]
forall {a}. (a -> Bool) -> [a] -> [a]
filter a -> Bool
p [a]
x
    filterLast a -> Bool
p (a
x:[a]
xs) = a
xa -> [a] -> [a]
forall a. a -> [a] -> [a]
:(a -> Bool) -> [a] -> [a]
filterLast a -> Bool
p [a]
xs
    getOutput' :: Handle -> IO [ByteString]
getOutput' Handle
h = do
      Bool
eof <- Handle -> IO Bool
hIsEOF Handle
h
      if Bool
eof
        then [ByteString] -> IO [ByteString]
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return []
        else (:) (ByteString -> [ByteString] -> [ByteString])
-> IO ByteString -> IO ([ByteString] -> [ByteString])
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Handle -> IO ByteString
BS.hGetLine Handle
h IO ([ByteString] -> [ByteString])
-> IO [ByteString] -> IO [ByteString]
forall a b. IO (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> Handle -> IO [ByteString]
getOutput Handle
h
    getOutput :: Handle -> IO [ByteString]
getOutput Handle
h = IO [ByteString]
-> (IOException -> IO [ByteString]) -> IO [ByteString]
forall e a. Exception e => IO a -> (e -> IO a) -> IO a
catch
      (Handle -> IO [ByteString]
getOutput' Handle
h)
      (\(IOException
_ :: IOException) -> [ByteString] -> IO [ByteString]
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return [ByteString
partialInstance])
    printContentOnError :: Maybe (IORef Bool) -> ProcessHandle -> IO ()
printContentOnError Maybe (IORef Bool)
abort ProcessHandle
ph = do
      ExitCode
code <- ProcessHandle -> IO ExitCode
waitForProcess ProcessHandle
ph
      Bool
aborted <- IO Bool -> (IORef Bool -> IO Bool) -> Maybe (IORef Bool) -> IO Bool
forall b a. b -> (a -> b) -> Maybe a -> b
maybe (Bool -> IO Bool
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Bool
False) IORef Bool -> IO Bool
forall a. IORef a -> IO a
readIORef Maybe (IORef Bool)
abort
      Bool -> IO () -> IO ()
forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
when (ExitCode
code ExitCode -> ExitCode -> Bool
forall a. Eq a => a -> a -> Bool
== Int -> ExitCode
ExitFailure Int
1 Bool -> Bool -> Bool
&& Bool -> Bool
not Bool
aborted)
        (IO () -> IO ()) -> IO () -> IO ()
forall a b. (a -> b) -> a -> b
$ String -> IO ()
putOutLn (String -> IO ()) -> String -> IO ()
forall a b. (a -> b) -> a -> b
$ String
"Failed parsing the Alloy code:\n" String -> String -> String
forall a. Semigroup a => a -> a -> a
<> String
content

partialInstance :: ByteString
partialInstance :: ByteString
partialInstance = ByteString
"---PARTIAL_INSTANCE---"

{-|
Removes lines such as

@
[main] INFO kodkod.engine.config.Reporter - detecting symmetries ...
[main] INFO kodkod.engine.config.Reporter - detected 16 equivalence classes of atoms ...
[main] INFO kodkod.engine.config.Reporter - optimizing bounds and formula (breaking predicate symmetries, inlining, skolemizing) ...
[main] INFO kodkod.engine.config.Reporter - translating to boolean ...
[main] INFO kodkod.engine.config.Reporter - generating lex-leader symmetry breaking predicate ...
@

and

@
[main] WARN kodkod.engine.config.Reporter - Temporal formula: will be reduced to possibly unsound static version.
@

and

@
PARTIAL_INSTANCE
@

which seem to be appearing since Alloy-6.0.0
-}
removeInfoLines :: [ByteString] -> [ByteString]
removeInfoLines :: [ByteString] -> [ByteString]
removeInfoLines (ByteString
x:[ByteString]
xs)
  | Just ByteString
_ <- ByteString -> ByteString -> Maybe ByteString
BS.stripPrefix ByteString
"[main] INFO" ByteString
x
  = [ByteString] -> [ByteString]
removeInfoLines [ByteString]
xs
  | Just ByteString
_ <- ByteString -> ByteString -> Maybe ByteString
BS.stripPrefix ByteString
"[main] WARN" ByteString
x
  = [ByteString] -> [ByteString]
removeInfoLines [ByteString]
xs
  | ByteString
x ByteString -> ByteString -> Bool
forall a. Eq a => a -> a -> Bool
== ByteString
partialInstance
  = [ByteString] -> [ByteString]
removeInfoLines [ByteString]
xs
removeInfoLines [ByteString]
xs = [ByteString]
xs

{-|
Start a new sub process that communicates with the worker process
if a timeout is provided.
Execution is aborted by closing all handles and
killing the underlying worker processes after the given amount of time
(if it has not finished by then).
The process will wait for the sub process to make the result available.

If the provided timeout is 'Nothing', evaluation happens without
scheduled interruption in the main thread.
-}
withTimeout
  :: Handle
  -- ^ the input handle (of the worker) to close
  -> Handle
  -- ^ the output handle (of the worker) to close
  -> Handle
  -- ^ the error handle (of the worker) to close
  -> ProcessHandle
  -- ^ the worker process handle
  -> Maybe (IORef Bool)
  -- ^ the IORef to communicate process abortion on Windows
  -> Maybe Int
  -- ^ the timeout (Nothing if no timeout)
  -> IO a
  -- ^ some action interacting with the worker and its handles
  -> IO a
withTimeout :: forall a.
Handle
-> Handle
-> Handle
-> ProcessHandle
-> Maybe (IORef Bool)
-> Maybe Int
-> IO a
-> IO a
withTimeout Handle
_ Handle
_ Handle
_ ProcessHandle
_  Maybe (IORef Bool)
_     Maybe Int
Nothing  IO a
p = IO a
p
withTimeout Handle
i Handle
o Handle
e ProcessHandle
ph Maybe (IORef Bool)
abort (Just Int
t) IO a
p = IO a -> (Async a -> IO a) -> IO a
forall a b. IO a -> (Async a -> IO b) -> IO b
withAsync IO a
p ((Async a -> IO a) -> IO a) -> (Async a -> IO a) -> IO a
forall a b. (a -> b) -> a -> b
$ \Async a
a -> do
  Int -> IO ()
threadDelay Int
t
  Maybe (IORef Bool) -> (IORef Bool -> IO ()) -> IO ()
forall (m :: * -> *) a.
Applicative m =>
Maybe a -> (a -> m ()) -> m ()
whenJust Maybe (IORef Bool)
abort (IORef Bool -> Bool -> IO ()
forall a. IORef a -> a -> IO ()
`atomicWriteIORef` Bool
True)
  (IO () -> IO ()) -> [IO ()] -> IO ()
forall (f :: * -> *) a b. Foldable f => (a -> IO b) -> f a -> IO ()
mapConcurrently_ IO () -> IO ()
forall a. a -> a
id [
    Handle -> IO ()
hClose Handle
e,
    Handle -> IO ()
hClose Handle
o,
    ProcessHandle -> IO ()
terminateProcess ProcessHandle
ph
    ]
  Handle -> IO ()
hClose Handle
i
  Async a -> IO a
forall a. Async a -> IO a
wait Async a
a

{-|
Get the class path of all files in the data directory.

Returns the class path.
-}
getClassPath :: IO FilePath
getClassPath :: IO String
getClassPath =
  String -> String -> String -> String -> String
concatPaths (String -> String -> String -> String -> String)
-> IO String -> IO (String -> String -> String -> String)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> IO String
getDataDir IO (String -> String -> String -> String)
-> IO String -> IO (String -> String -> String)
forall a b. IO (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> IO String
alloyJar IO (String -> String -> String)
-> IO String -> IO (String -> String)
forall a b. IO (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> IO String
commonsCliJar IO (String -> String) -> IO String -> IO String
forall a b. IO (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> IO String
slf4jJar
  where
    concatPaths :: String -> String -> String -> String -> String
concatPaths String
w String
x String
y String
z = String -> [String] -> String
forall a. [a] -> [[a]] -> [a]
intercalate
      [Char
searchPathSeparator]
      [String
w, String
x, String
y, String
z]