CurryInfo: cdbi-3.2.0 / Database.CDBI.ER.runInTransaction

definition: 
runInTransaction :: DBAction a -> DBAction a
runInTransaction act = DBAction $ \conn -> do
  res <- flip runDBAction conn $ do
           begin
           kes1 <- getForeignKeyErrors
           r <- act
           kes2 <- getForeignKeyErrors
           return (kes2 \\ kes1, r)
  case res of
    Left err -> runDBAction rollback conn >> return (Left err)
    Right (newkes,ares) ->
      if null newkes
        then runDBAction commit   conn >> return (Right ares)
        else runDBAction rollback conn >>
             return (Left (DBError ConstraintViolation (showFKErrors newkes)))
 where
  showFKErrors = intercalate "," . nub .
    concatMap (\row -> if length row < 3 then []
                                         else [row!!0 ++ "/" ++ row!!2])
demand: 
no demanded arguments
deterministic: 
deterministic operation
documentation: 
--- Run a `DBAction` as a transaction.
--- In case of an error, it will rollback all changes, otherwise, the changes
--- are committed. The transaction is also checked whether foreign key errors
--- have been introduced so that a transaction which introduces
--- foreign key errors will never be committed.
--- @param act  - The `DBAction`
--- @param conn - The `Connection` to the database on which the transaction
--- shall be executed.
failfree: 
<FAILING>
indeterministic: 
referentially transparent operation
infix: 
no fixity defined
iotype: 
{(_) |-> _}
name: 
runInTransaction
precedence: 
no precedence defined
result-values: 
_
signature: 
DBAction a -> DBAction a
solution-complete: 
operation might suspend on free variables
terminating: 
possibly non-terminating
totally-defined: 
possibly non-reducible on same data term