Expression such as boundVariable + 10 fails on Gremlin Server #18
Description
Tested with: tinkerpop/gremlin-server:3.7.3 (docker container)
README.md has the following code.
import Control.Exception.Safe (bracket, try, SomeException)
import Data.Foldable (toList)
import Data.Greskell.Greskell (Greskell) -- from greskell package
import Data.Greskell.Binder -- from greskell package
(Binder, newBind, runBinder)
import Network.Greskell.WebSocket -- from greskell-websocket package
(connect, close, submit, slurpResults)
import System.IO (hPutStrLn, stderr)
submitExample :: IO [Int]
submitExample =
bracket (connect "localhost" 8182) close $ \client -> do
let (g, binding) = runBinder $ plusTen 50
result_handle <- submit client g (Just binding)
fmap toList $ slurpResults result_handle
plusTen :: Int -> Binder (Greskell Int)
plusTen x = do
var_x <- newBind x
return $ var_x + 10
main = hspec $ specify "submit" $ do
egot <- try submitExample :: IO (Either SomeException [Int])
case egot of
Left e -> do
hPutStrLn stderr ("submit error: " ++ show e)
hPutStrLn stderr (" We ignore the error. Probably there's no server running?")
Right got -> do
hPutStrLn stderr ("submit success: " ++ show got)
got `shouldBe` [60]This fails, because the gremlin-server emits an exception with message "unable to resolve class __v0".
This is due to the bug in Groovy: [GROOVY-10355] Compiler interpret variable name as class name when in parentheses. - ASF JIRA
The above greskell code constructs a script (__v0)+(10). According to the above bug, the Groovy compiler treats (__v0) as the typecast unary operator and + as the unary plus, thus it treats __v0 as a type name.
I confirmed that ((__v0))+(10) worked as expected, that is, __v0 was resolved as a varible name.