Parse a line of SMTP dialogue and run handleSmtpCmd to determine the Event. In case of syntax errors, SyntaxErrorIn or Unrecognized will be returned. Inputs must be terminated with crlf. See fixCRLF.

For those who want to parse the SmtpCmd themselves. Calling this function in HaveQuit or HaveData will fail an assertion. If assert is disabled, it will return respectively Shutdown and StartData again.

The smtpCmd parser will create this data type from a string. Note that all command parsers expect their input to be terminated with crlf.

The most general e-mail address has the form: <[@route,...:]user@domain>. This type, too, supports show and read. Note that a "shown" address is always enclosed in angular brackets. When comparing two mailboxes for equality, the hostname is case-insensitive.

nullPath = Mailbox [] "" "" = "<>"

postmaster = Mailbox [] "postmaster" "" = "<postmaster>"

An SMTP reply is a three-digit return code plus some waste of bandwidth called "comments". This is what the list of strings is for; one string per line in the reply. show will append an "\r\n" end-of-line marker to each entry in that list, so that the resulting string is ready to be sent back to the peer. For example:

>>> show $ Reply (Code Success MailSystem 0) ["worked", "like", "a charm" ]
"250-worked\r\n250-like\r\n250 a charm\r\n"

If the message is an empty list [], a default text will be constructed:

>>> show $ Reply (Code Success MailSystem 0) []
"250 Success in category MailSystem\r\n"

Construct a Reply. Fails assert if invalid numbers are given.

A reply constitutes "success" if the status code is any of PreliminarySuccess, Success, or IntermediateSuccess.

A reply constitutes "failure" if the status code is either PermanentFailure or TransientFailure.

The replies 221 and 421 signify Shutdown.

The SMTP parsers defined here correspond to the commands specified in RFC2821, so I won't document them individually.

This parser recognizes any of the SMTP commands defined below. Note that all command parsers expect their input to be terminated with crlf.

The parser name "data" was taken.

May have an optional word argument, but it is ignored.

TODO: Add IPv6 address and general literals

This is a useful addition: The parser accepts an atom or a quoted_string.

Make the string crlf terminated no matter what. '\n' is expanded, otherwise crlf is appended. Note that if the string was terminated incorrectly before, it still is. This function is useful when reading input with hGetLine which removes the end-of-line delimiter.

Construct a parser for a command without arguments. Expects crlf!

Construct a parser for a command with an argument, which the given parser will handle. The result of the argument parser will be applied to the type constructor before it is returned. Expects crlf!