Re: [JVM-B] The best way to use a JVMBridge-based module.

[Artem Gr <ar...@bi...>]

Attached is the version of the JDBC module which displays how JVMUser 
monad is hidden from the user.
The user is provided by the module with following methods:
startJVMcp :: [FilePath] -> IO AttachedJVM
jdbcDriverConnection :: String -> String -> String -> String -> 
AttachedJVM -> IO JConnection

> Artem Gr wrote:
>> What i'm currently bothered with, is the imposing requirement of the 
>> JVM monad on the user of the module.
>> Is it possible to do (in the user code):
>>
>>  main = runWithClasspath cp do
>>    jdbc <- jdbcDriverConnection ...
>>    callIO (mainProg jdbc)
>>  mainProg jdbc = do
>>    rs <- query "select 0 from dual" jdbc
>>    close jdbc
>>
>> That is, to wrap the created JVM monad in the "jdbc" variable and 
>> wrap all the JDBC functions except the jdbcDriverConnection in the IO 
>> monad, but make them do the JVM monad work inside. I suppose it is 
>> somehow possible by merging the IO and JVM monads into another monad, 
>> but i haven't yet used such mechanics.
>>
>> That is, is it possible to write the "callJVM" function, which, like 
>> "callIO", invokes the code inside the JVM monad (without trying to 
>> create a second JVM every time).