In REPL, if you can determine that an error has occurred on one line, you should not start a new line

[C-BJ]

Here it should probably just report the error instead of starting a new line

[mtshiba]

It will be necessary to have Parser inspect the input to determine if it is invalid, valid, or needs to be continued.

[C-BJ]

Remember to delete the code added in #154 after thoroughly solving the issue

[mtshiba]

Perhaps the option NeedNextLine should be added to ErrorKind: the REPL gives input to the parser, and when an error is returned, if the error type is NeedNextLine, it prompts for the next line of input.