This is a small command line REPL (read-eval-print loop) that drives a simple in-memory key/value storage system. This system should also allow for nested transactions. A transaction can then be committed or aborted.
To "play" add and remove key value pairs with the commands below:
COMMANDS
READ <key> Reads and prints, to stdout, the val associated with key. If the value is not present an error is printed to stderr.
WRITE <key> <val> Stores val in key.
DELETE <key> Removes all key from store. Future READ commands on that key will return an error.
START Start a transaction.
COMMIT Commit a transaction. All actions in the current transaction are committed to the parent transaction or the root store. If there is no current transaction an error is output to stderr.
ABORT Abort a transaction. All actions in the current transaction are discarded.
QUIT Exit the REPL cleanly. A message to stderr may be output.