hsemail-ns-1.3.1: Text/ParserCombinators/Parsec/Rfc2822NS.hs
{- |
Module : Text.ParserCombinators.Parsec.Rfc2822
Copyright : (c) 2008 Peter Simons
License : BSD3
Maintainer : simons@cryp.to
Stability : provisional
Portability : portable
This module provides parsers for the grammar defined in
RFC2822, \"Internet Message Format\",
<http://www.faqs.org/rfcs/rfc2822.html>.
/Please note:/ The module is not particularly well tested.
Addendum for Nonstandard Version:
This module deviates from the RFC currently in
* Allowing for non-standard line endings.
These allowances are subject to change, and should not be
used when parsing incoming messages, only for parsing messages
that have been stored on disk. The goal of these nonstandard
Parsers is to provide a higher probability of parsing Common_
Headers (rather than only those explicitly defined in the RFC)
as well as allowing for potential oddities / changes that may
occur during storage of an email message. These parsers have
be rebranded so as not to conflict with the standard parsers
available from the excellent 'hsemail' package, upon which
this package depends. For patches to this package only (namely
'hsemail-ns', patches should be sent to <jfredett@gmail.com>,
for patches to the Proper parsers, you can send them to the
original maintainer.
-}
module Text.ParserCombinators.Parsec.Rfc2822NS where
import System.Time
import Data.Char ( ord )
import Data.List ( intersperse )
import Control.Monad ( liftM )
import Text.ParserCombinators.Parsec
import Text.ParserCombinators.Parsec.Rfc2234NS hiding ( quotedPair, quotedString )
-- * Useful parser combinators
-- |Return @Nothing@ if the given parser doesn't match. This
-- combinator is included in the latest parsec distribution as
-- @optionMaybe@, but ghc-6.6.1 apparently doesn't have it.
maybeOption :: GenParser tok st a -> GenParser tok st (Maybe a)
maybeOption = option Nothing . liftM Just
-- |@unfold@ @=@ @between (optional cfws) (optional cfws)@
unfold :: CharParser a b -> CharParser a b
unfold = between (optional cfws) (optional cfws)
-- |Construct a parser for a message header line from the
-- header's name and a parser for the body.
header :: String -> CharParser a b -> CharParser a b
header n p = let nameString = caseString (n ++ ":")
in
between nameString crlf p <?> (n ++ " header line")
-- |Like 'header', but allows the obsolete white-space rules.
obsHeader :: String -> CharParser a b -> CharParser a b
obsHeader n p = let nameString = caseString n >> many wsp >> char ':'
in
between nameString crlf p <?> ("obsolete " ++ n ++ " header line")
-- ** Primitive Tokens (section 3.2.1)
-- |Match any US-ASCII non-whitespace control character.
noWsCtl :: CharParser a Char
noWsCtl = satisfy (\c -> ord c `elem` ([1..8] ++ [11,12] ++ [14..31] ++ [127]))
<?> "US-ASCII non-whitespace control character"
-- |Match any US-ASCII character except for @\r@, @\n@.
text :: CharParser a Char
text = satisfy (\c -> ord c `elem` ([1..9] ++ [11,12] ++ [14..127]))
<?> "US-ASCII character (excluding CR and LF)"
-- |Match any of the RFC's \"special\" characters: @()\<\>[]:;\@,.\\\"@.
specials :: CharParser a Char
specials = oneOf "()<>[]:;@,.\\\"" <?> "one of ()<>[]:;@,.\\\""
-- ** Quoted characters (section 3.2.2)
-- |Match a \"quoted pair\". All characters matched by 'text' may be
-- quoted. Note that the parsers returns /both/ characters, the
-- backslash and the actual content.
quotedPair :: CharParser a String
quotedPair = do { char '\\'; r <- text; return ['\\',r] }
<?> "quoted pair"
-- ** Folding white space and comments (section 3.2.3)
-- |Match \"folding whitespace\". That is any combination of 'wsp' and
-- 'crlf' followed by 'wsp'.
fws :: CharParser a String
fws = do r <- many1 $ choice [ blanks, linebreak]
return (concat r)
where
blanks = many1 wsp
linebreak = try $ do { r1 <- crlf; r2 <- blanks; return (r1 ++ r2) }
-- |Match any non-whitespace, non-control character except for \"@(@\",
-- \"@)@\", and \"@\\@\". This is used to describe the legal content of
-- 'comment's.
--
-- /Note/: This parser accepts 8-bit characters, even though this is
-- not legal according to the RFC. Unfortunately, 8-bit content in
-- comments has become fairly common in the real world, so we'll just
-- accept the fact.
ctext :: CharParser a Char
ctext = noWsCtl <|> satisfy (\c -> ord c `elem` ([33..39] ++ [42..91] ++ [93..126] ++ [128..255]))
<?> "any regular character (excluding '(', ')', and '\\')"
-- |Match a \"comments\". That is any combination of 'ctext',
-- 'quotedPair 's, and 'fws' between brackets. Comments may nest.
comment :: CharParser a String
comment = do char '('
r1 <- many ccontent
r2 <- option [] fws
char ')'
return ("(" ++ concat r1 ++ r2 ++ ")")
<?> "comment"
where
ccontent = try $ do r1 <- option [] fws
r2 <- choice [many1 ctext, quotedPair , comment]
return (r1 ++ r2)
-- |Match any combination of 'fws' and 'comments'.
cfws :: CharParser a String
cfws = do r <- many1 $ choice [ fws, comment ]
return (concat r)
-- ** Atom (section 3.2.4)
-- |Match any US-ASCII character except for control characters,
-- 'specials', or space. 'atom' and 'dotAtom' are made up of this.
atext :: CharParser a Char
atext = alpha <|> digit <|> oneOf "!#$%&'*+-/=?^_`{|}~"
<?> "US-ASCII character (excluding controls, space, and specials)"
-- |Match one or more 'atext' characters and skip any preceeding or
-- trailing 'cfws'.
atom :: CharParser a String
atom = unfold (many1 atext <?> "atom")
-- |Match 'dotAtomText' and skip any preceeding or trailing 'cfws'.
dotAtom :: CharParser a String
dotAtom = unfold (dotAtomText <?> "dot atom")
-- |Match two or more 'atext's interspersed by dots.
dotAtomText :: CharParser a String
dotAtomText = do r <- sepBy1 (many1 atext) (char '.')
return (concat (intersperse "." r))
<?> "dot atom content"
-- ** Quoted strings (section 3.2.5)
-- |Match any non-whitespace, non-control US-ASCII character except
-- for \"@\\@\" and \"@\"@\".
qtext :: CharParser a Char
qtext = noWsCtl <|> satisfy (\c -> ord c `elem` ([33] ++ [35..91] ++ [93..126]))
<?> "US-ASCII character (excluding '\\', and '\"')"
-- |Match either 'qtext' or 'quotedPair '.
qcontent :: CharParser a String
qcontent = many1 qtext <|> quotedPair
<?> "quoted string content"
-- |Match any number of 'qcontent' between double quotes. Any 'cfws'
-- preceeding or following the \"atom\" is skipped automatically.
quotedString :: CharParser a String
quotedString = unfold (do dquote
r1 <- many (do r1 <- option [] fws
r2 <- qcontent
return (r1 ++ r2))
r2 <- option [] fws
dquote
return ("\"" ++ concat r1 ++ r2 ++ "\""))
<?> "quoted string"
-- * Miscellaneous tokens (section 3.2.6)
-- |Match either 'atom' or 'quotedString'.
word :: CharParser a String
word = atom <|> quotedString <?> "word"
-- |Match either one or more 'word's or an 'obsPhrase'.
phrase :: CharParser a [String]
phrase = {- many1 word <?> "phrase" <|> -} obsPhrase
-- |Match any non-whitespace, non-control US-ASCII character except
-- for \"@\\@\" and \"@\"@\".
utext :: CharParser a Char
utext = noWsCtl <|> satisfy (\c -> ord c `elem` [33..126])
<?> "regular US-ASCII character (excluding '\\', and '\"')"
-- |Match any number of 'utext' tokens.
--
-- \"Unstructured text\" is used in free text fields such as 'subject'.
-- Please note that any comments or whitespace that prefaces or
-- follows the actual 'utext' is /included/ in the returned string.
unstructured :: CharParser a String
unstructured = do r1 <- option [] fws
r2 <- many (do r3 <- utext
r4 <- option [] fws
return (r3 : r4))
return (r1 ++ concat r2)
<?> "unstructured text"
-- * Date and Time Specification (section 3.3)
-- |Parse a date and time specification of the form
--
-- > Thu, 19 Dec 2002 20:35:46 +0200
--
-- where the weekday specification \"@Thu,@\" is optional. The parser
-- returns a 'CalendarTime', which is set to the appropriate values.
-- Note, though, that not all fields of 'CalendarTime' will
-- necessarily be set correctly! Obviously, when no weekday has been
-- provided, the parser will set this field to 'Monday' - regardless
-- of whether the day actually is a monday or not. Similarly, the day
-- of the year will always be returned as @0@. The timezone name will
-- always be empty: @\"\"@.
--
-- Nor will the 'dateTime' parser perform /any/ consistency checking.
-- It will accept
--
-- > 40 Apr 2002 13:12 +0100
--
-- as a perfectly valid date.
--
-- In order to get all fields set to meaningful values, and in order
-- to verify the date's consistency, you will have to feed it into any
-- of the conversion routines provided in "System.Time", such as
-- 'toClockTime'. (When doing this, keep in mind that most functions
-- return /local time/. This will not necessarily be the time you're
-- expecting.)
dateTime :: CharParser a CalendarTime
dateTime = do wd <- option Monday (try (do wd <- dayOfWeek
char ','
return wd))
(y,m,d) <- date
fws
(td,z) <- time
optional cfws
return (CalendarTime y m d (tdHour td) (tdMin td) (tdSec td) 0 wd 0 "" z False)
<?> "date/time specification"
-- |This parser will match a 'dayName', optionally wrapped in folding
-- whitespace, or an 'obsDayOfWeek' and return it's 'Day' value.
dayOfWeek :: CharParser a Day
dayOfWeek = try (between (optional fws) (optional fws) dayName <?> "name of a day-of-the-week")
<|> obsDayOfWeek
-- |This parser will the abbreviated weekday names (\"@Mon@\", \"@Tue@\", ...)
-- and return the appropriate 'Day' value.
dayName :: CharParser a Day
dayName = do { caseString "Mon"; return Monday }
<|> do { try (caseString "Tue"); return Tuesday }
<|> do { caseString "Wed"; return Wednesday }
<|> do { caseString "Thu"; return Thursday }
<|> do { caseString "Fri"; return Friday }
<|> do { try (caseString "Sat"); return Saturday }
<|> do { caseString "Sun"; return Sunday }
<?> "name of a day-of-the-week"
-- |This parser will match a date of the form \"@dd:mm:yyyy@\" and return
-- a tripple of the form (Int,Month,Int) - corresponding to
-- (year,month,day).
date :: CharParser a (Int,Month,Int)
date = do d <- day
m <- month
y <- year
return (y,m,d)
<?> "date specification"
-- |This parser will match a four digit number and return it's integer
-- value. No range checking is performed.
year :: CharParser a Int
year = do y <- manyN 4 digit
return (read y :: Int)
<?> "year"
-- |This parser will match a 'monthName', optionally wrapped in
-- folding whitespace, or an 'obsMonth' and return it's 'Month'
-- value.
month :: CharParser a Month
month = try (between (optional fws) (optional fws) monthName <?> "month name")
<|> obsMonth
-- |This parser will the abbreviated month names (\"@Jan@\", \"@Feb@\", ...)
-- and return the appropriate 'Month' value.
monthName :: CharParser a Month
monthName = do { try (caseString "Jan"); return January }
<|> do { caseString "Feb"; return February }
<|> do { try (caseString "Mar"); return March }
<|> do { try (caseString "Apr"); return April }
<|> do { caseString "May"; return May }
<|> do { try (caseString "Jun"); return June }
<|> do { caseString "Jul"; return July }
<|> do { caseString "Aug"; return August }
<|> do { caseString "Sep"; return September }
<|> do { caseString "Oct"; return October }
<|> do { caseString "Nov"; return November }
<|> do { caseString "Dec"; return December }
<?> "month name"
-- |Match either an 'obsDay', or a one or two digit number and return it.
day :: CharParser a Int
day = try (do { optional fws; r <- manyNtoM 1 2 digit; return (read r :: Int) }) <|> obsDay
<?> "day"
-- |This parser will match a 'timeOfDay' specification followed by a
-- 'zone'. It returns the tuple (TimeDiff,Int) corresponding to the
-- return values of either parser.
time :: CharParser a (TimeDiff,Int)
time = do t <- timeOfDay
fws
z <- zone
return (t,z)
<?> "time and zone specification"
-- |This parser will match a time-of-day specification of \"@hh:mm@\" or
-- \"@hh:mm:ss@\" and return the corrsponding time as a 'TimeDiff'.
timeOfDay :: CharParser a TimeDiff
timeOfDay = do h <- hour
char ':'
m <- minute
s <- option 0 (do { char ':'; second } )
return (TimeDiff 0 0 0 h m s 0)
<?> "time specification"
-- |This parser will match a two-digit number and return it's integer
-- value. No range checking is performed.
hour :: CharParser a Int
hour = do r <- count 2 digit
return (read r :: Int)
<?> "hour"
-- |This parser will match a two-digit number and return it's integer
-- value. No range checking is performed.
minute :: CharParser a Int
minute = do r <- count 2 digit
return (read r :: Int)
<?> "minute"
-- |This parser will match a two-digit number and return it's integer
-- value. No range checking takes place.
second :: CharParser a Int
second = do r <- count 2 digit
return (read r :: Int)
<?> "second"
-- |This parser will match a timezone specification of the form
-- \"@+hhmm@\" or \"@-hhmm@\" and return the zone's offset to UTC in
-- seconds as an integer. 'obsZone' is matched as well.
zone :: CharParser a Int
zone = ( do char '+'
h <- hour
m <- minute
return (((h*60)+m)*60)
<|> do char '-'
h <- hour
m <- minute
return (-((h*60)+m)*60)
<?> "time zone"
)
<|> obsZone
-- * Address Specification (section 3.4)
-- |A NameAddr is composed of an optional realname a mandatory
-- e-mail 'address'.
data NameAddr = NameAddr { nameAddrName :: Maybe String
, nameAddrAddr :: String
}
deriving (Show,Eq)
-- |Parse a single 'mailbox' or an address 'group' and return the
-- address(es).
address :: CharParser a [NameAddr]
address = try (do { r <- mailbox; return [r] }) <|> group
<?> "address"
-- |Parse a 'nameAddr' or an 'addrSpec' and return the
-- address.
mailbox :: CharParser a NameAddr
mailbox = try nameAddr
<|> liftM (NameAddr Nothing) addrSpec
<?> "mailbox"
-- |Parse an 'angleAddr', optionally prefaced with a 'displayName',
-- and return the address.
nameAddr :: CharParser a NameAddr
nameAddr = do name <- maybeOption displayName
addr <- angleAddr
return (NameAddr name addr)
<?> "name address"
-- |Parse an 'angle_addr' or an 'obsAngleAddr' and return the address.
angleAddr :: CharParser a String
angleAddr = try (unfold (do char '<'
r <- addrSpec
char '>'
return r)
<?> "angle address"
)
<|> obsAngleAddr
-- |Parse a \"group\" of addresses. That is a 'displayName', followed
-- by a colon, optionally followed by a 'mailboxList', followed by a
-- semicolon. The found address(es) are returned - what may be none.
-- Here is an example:
--
-- > parse group "" "my group: user1@example.org, user2@example.org;"
--
-- This input comes out as:
--
-- > Right ["user1@example.org","user2@example.org"]
group :: CharParser a [NameAddr]
group = do displayName
char ':'
r <- option [] mailboxList
unfold $ char ';'
return r
<?> "address group"
-- |Parse and return a 'phrase'.
displayName :: CharParser a String
displayName = phrase >>= return . unwords
<?> "display name"
-- |Parse a list of 'mailbox' addresses, every two addresses being
-- separated by a comma, and return the list of found address(es).
mailboxList :: CharParser a [NameAddr]
mailboxList = sepBy mailbox (char ',') <?> "mailbox list"
-- |Parse a list of 'address' addresses, every two addresses being
-- separated by a comma, and return the list of found address(es).
addressList :: CharParser a [NameAddr]
addressList = do { r <-sepBy address (char ','); return (concat r) }
<?> "address list"
-- ** Addr-spec specification (section 3.4.1)
-- |Parse an \"address specification\". That is a 'localPart', followed
-- by an \"@\@@\" character, followed by a 'domain'. Return the complete
-- address as 'String', ignoring any whitespace or any comments.
addrSpec :: CharParser a String
addrSpec = do r1 <- localPart
char '@'
r2 <- domain
return (r1 ++ "@" ++ r2)
<?> "address specification"
-- |Parse and return a \"local part\" of an 'addrSpec'. That is either
-- a 'dotAtom' or a 'quotedString'.
localPart :: CharParser a String
localPart = dotAtom <|> quotedString
<?> "address' local part"
-- |Parse and return a \"domain part\" of an 'addrSpec'. That is either
-- a 'dotAtom' or a 'domainLiteral'.
domain :: CharParser a String
domain = dotAtom <|> domainLiteral
<?> "address' domain part"
-- |Parse a \"domain literal\". That is a \"@[@\" character, followed by
-- any amount of 'dcontent', followed by a terminating \"@]@\"
-- character. The complete string is returned verbatim.
domainLiteral :: CharParser a String
domainLiteral = unfold (do char '['
r <- many $ do { optional fws; dcontent }
optional fws
char ']'
return ("[" ++ concat r ++ "]"))
<?> "domain literal"
-- |Parse and return any characters that are legal in a
-- 'domainLiteral'. That is 'dtext' or a 'quotedPair '.
dcontent :: CharParser a String
dcontent = many1 dtext <|> quotedPair
<?> "domain literal content"
-- |Parse and return any ASCII characters except \"@[@\", \"@]@\", and
-- \"@\\@\".
dtext :: CharParser a Char
dtext = noWsCtl
<|> satisfy (\c -> ord c `elem` ([33..90] ++ [94,127]))
<?> "character (excluding '[', ']', and '\\')"
-- * Overall message syntax (section 3.5)
-- |This data type repesents a parsed Internet Message as defined in
-- this RFC. It consists of an arbitrary number of header lines,
-- represented in the 'Field' data type, and a message body, which may
-- be empty.
data Message = Message [Field] String
deriving (Show)
-- |Parse a complete message as defined by this RFC and it broken down
-- into the separate header fields and the message body. Header lines,
-- which contain syntax errors, will not cause the parser to abort.
-- Rather, these headers will appear as 'OptionalField's (which are
-- unparsed) in the resulting 'Message'. A message must be really,
-- really badly broken for this parser to fail.
--
-- This behaviour was chosen because it is impossible to predict what
-- the user of this module considers to be a fatal error;
-- traditionally, parsers are very forgiving when it comes to Internet
-- messages.
--
-- If you want to implement a really strict parser, you'll have to put
-- the appropriate parser together yourself. You'll find that this is
-- rather easy to do. Refer to the 'fields' parser for further details.
message :: CharParser a Message
message = do f <- fields
b <- option [] (do crlf
body)
return (Message f b)
-- |This parser will return a message body as specified by this RFC;
-- that is basically any number of 'text' characters, which may be
-- divided into separate lines by 'crlf'.
body :: CharParser a String
body = do r1 <- many (try (do line <- many text
eol <- crlf
return (line ++ eol)))
r2 <- many text
return (concat r1 ++ r2)
-- * Field definitions (section 3.6)
-- |This data type represents any of the header fields defined in this
-- RFC. Each of the various instances contains with the return value
-- of the corresponding parser.
data Field = OptionalField String String
| From [NameAddr]
| Sender NameAddr
| ReturnPath String
| ReplyTo [NameAddr]
| To [NameAddr]
| Cc [NameAddr]
| Bcc [NameAddr]
| MessageID String
| InReplyTo [String]
| References [String]
| Subject String
| Comments String
| Keywords [[String]]
| Date CalendarTime
| ResentDate CalendarTime
| ResentFrom [NameAddr]
| ResentSender NameAddr
| ResentTo [NameAddr]
| ResentCc [NameAddr]
| ResentBcc [NameAddr]
| ResentMessageID String
| ResentReplyTo [NameAddr]
| Received ([(String,String)], CalendarTime)
| ObsReceived [(String,String)]
deriving (Show)
-- |This parser will parse an arbitrary number of header fields as
-- defined in this RFC. For each field, an appropriate 'Field' value
-- is created, all of them making up the 'Field' list that this parser
-- returns.
--
-- If you look at the implementation of this parser, you will find
-- that it uses Parsec's 'try' modifier around /all/ of the fields.
-- The idea behind this is that fields, which contain syntax errors,
-- fall back to the catch-all 'optionalField'. Thus, this parser will
-- hardly ever return a syntax error -- what conforms with the idea
-- that any message that can possibly be accepted /should/ be.
fields :: CharParser a [Field]
fields = many ( try (do { r <- from; return (From r) })
<|> try (do { r <- sender; return (Sender r) })
<|> try (do { r <- returnPath; return (ReturnPath r) })
<|> try (do { r <- replyTo; return (ReplyTo r) })
<|> try (do { r <- to; return (To r) })
<|> try (do { r <- cc; return (Cc r) })
<|> try (do { r <- bcc; return (Bcc r) })
<|> try (do { r <- messageId; return (MessageID r) })
<|> try (do { r <- inReplyTo; return (InReplyTo r) })
<|> try (do { r <- references; return (References r) })
<|> try (do { r <- subject; return (Subject r) })
<|> try (do { r <- comments; return (Comments r) })
<|> try (do { r <- keywords; return (Keywords r) })
<|> try (do { r <- origDate; return (Date r) })
<|> try (do { r <- resentDate; return (ResentDate r) })
<|> try (do { r <- resentFrom; return (ResentFrom r) })
<|> try (do { r <- resentSender; return (ResentSender r) })
<|> try (do { r <- resentTo; return (ResentTo r) })
<|> try (do { r <- resentCc; return (ResentCc r) })
<|> try (do { r <- resentBcc; return (ResentBcc r) })
<|> try (do { r <- resentMsgId; return (ResentMessageID r) })
<|> try (do { r <- received; return (Received r) })
-- catch all
<|> (do { (name,cont) <- optionalField; return (OptionalField name cont) })
)
-- ** The origination date field (section 3.6.1)
-- |Parse a \"@Date:@\" header line and return the date it contains a
-- 'CalendarTime'.
origDate :: CharParser a CalendarTime
origDate = header "Date" dateTime
-- ** Originator fields (section 3.6.2)
-- |Parse a \"@From:@\" header line and return the 'mailboxList'
-- address(es) contained in it.
from :: CharParser a [NameAddr]
from = header "From" mailboxList
-- |Parse a \"@Sender:@\" header line and return the 'mailbox' address
-- contained in it.
sender :: CharParser a NameAddr
sender = header "Sender" mailbox
-- |Parse a \"@Reply-To:@\" header line and return the 'addressList'
-- address(es) contained in it.
replyTo :: CharParser a [NameAddr]
replyTo = header "Reply-To" addressList
-- ** Destination address fields (section 3.6.3)
-- |Parse a \"@To:@\" header line and return the 'addressList'
-- address(es) contained in it.
to :: CharParser a [NameAddr]
to = header "To" addressList
-- |Parse a \"@Cc:@\" header line and return the 'addressList'
-- address(es) contained in it.
cc :: CharParser a [NameAddr]
cc = header "Cc" addressList
-- |Parse a \"@Bcc:@\" header line and return the 'addressList'
-- address(es) contained in it.
bcc :: CharParser a [NameAddr]
bcc = header "Bcc" (try addressList <|> do { optional cfws; return [] })
-- ** Identification fields (section 3.6.4)
-- |Parse a \"@Message-Id:@\" header line and return the 'msgId'
-- contained in it.
messageId :: CharParser a String
messageId = header "Message-ID" msgId
-- |Parse a \"@In-Reply-To:@\" header line and return the list of
-- 'msgId's contained in it.
inReplyTo :: CharParser a [String]
inReplyTo = header "In-Reply-To" (many1 msgId)
-- |Parse a \"@References:@\" header line and return the list of
-- 'msgId's contained in it.
references :: CharParser a [String]
references = header "References" (many1 msgId)
-- |Parse a \"@message ID:@\" and return it. A message ID is almost
-- identical to an 'angleAddr', but with stricter rules about folding
-- and whitespace.
msgId :: CharParser a String
msgId = unfold (do char '<'
idl <- idLeft
char '@'
idr <- idRight
char '>'
return ("<" ++ idl ++ "@" ++ idr ++ ">"))
<?> "message ID"
-- |Parse a \"left ID\" part of a 'msgId'. This is almost identical to
-- the 'localPart' of an e-mail address, but with stricter rules
-- about folding and whitespace.
idLeft :: CharParser a String
idLeft = dotAtomText <|> noFoldQuote
<?> "left part of an message ID"
-- |Parse a \"right ID\" part of a 'msgId'. This is almost identical to
-- the 'domain' of an e-mail address, but with stricter rules about
-- folding and whitespace.
idRight :: CharParser a String
idRight = dotAtomText <|> noFoldLiteral
<?> "right part of an message ID"
-- |Parse one or more occurences of 'qtext' or 'quotedPair ' and
-- return the concatenated string. This makes up the 'idLeft' of a
-- 'msgId'.
noFoldQuote :: CharParser a String
noFoldQuote = do dquote
r <- many (many1 qtext <|> quotedPair )
dquote
return ("\"" ++ concat r ++ "\"")
<?> "non-folding quoted string"
-- |Parse one or more occurences of 'dtext' or 'quotedPair ' and
-- return the concatenated string. This makes up the 'idRight' of a
-- 'msgId'.
noFoldLiteral :: CharParser a String
noFoldLiteral = do char '['
r <- many (many1 dtext <|> quotedPair )
char ']'
return ("\"" ++ concat r ++ "\"")
return ("[" ++ concat r ++ "]")
<?> "non-folding domain literal"
-- ** Informational fields (section 3.6.5)
-- |Parse a \"@Subject:@\" header line and return it's contents verbatim.
subject :: CharParser a String
subject = header "Subject" unstructured
-- |Parse a \"@Comments:@\" header line and return it's contents verbatim.
comments :: CharParser a String
comments = header "Comments" unstructured
-- |Parse a \"@Keywords:@\" header line and return the list of 'phrase's
-- found. Please not that each phrase is again a list of 'atom's, as
-- returned by the 'phrase' parser.
keywords :: CharParser a [[String]]
keywords = header "Keywords" (do r1 <- phrase
r2 <- many (do char ','
phrase)
return (r1:r2))
-- ** Resent fields (section 3.6.6)
-- |Parse a \"@Resent-Date:@\" header line and return the date it
-- contains as 'CalendarTime'.
resentDate :: CharParser a CalendarTime
resentDate = header "Resent-Date" dateTime
-- |Parse a \"@Resent-From:@\" header line and return the 'mailboxList'
-- address(es) contained in it.
resentFrom :: CharParser a [NameAddr]
resentFrom = header "Resent-From" mailboxList
-- |Parse a \"@Resent-Sender:@\" header line and return the 'mailboxList'
-- address(es) contained in it.
resentSender :: CharParser a NameAddr
resentSender = header "Resent-Sender" mailbox
-- |Parse a \"@Resent-To:@\" header line and return the 'mailbox'
-- address contained in it.
resentTo :: CharParser a [NameAddr]
resentTo = header "Resent-To" addressList
-- |Parse a \"@Resent-Cc:@\" header line and return the 'addressList'
-- address(es) contained in it.
resentCc :: CharParser a [NameAddr]
resentCc = header "Resent-Cc" addressList
-- |Parse a \"@Resent-Bcc:@\" header line and return the 'addressList'
-- address(es) contained in it. (This list may be empty.)
resentBcc :: CharParser a [NameAddr]
resentBcc = header "Resent-Bcc" ( try addressList
<|> do optional cfws
return []
)
<?> "Resent-Bcc: header line"
-- |Parse a \"@Resent-Message-ID:@\" header line and return the 'msgId'
-- contained in it.
resentMsgId :: CharParser a String
resentMsgId = header "Resent-Message-ID" msgId
-- ** Trace fields (section 3.6.7)
returnPath :: CharParser a String
returnPath = header "Return-Path:" path
path :: CharParser a String
path = unfold ( do char '<'
r <- choice [ try addrSpec, do { cfws; return [] } ]
char '>'
return ("<" ++ r ++ ">")
<|> obsPath
)
<?> "return path spec"
received :: CharParser a ([(String,String)], CalendarTime)
received = header "Received" (do r1 <- nameValList
char ';'
r2 <- dateTime
return (r1,r2))
nameValList :: CharParser a [(String,String)]
nameValList = do optional cfws
many1 nameValPair
<?> "list of name/value pairs"
nameValPair :: CharParser a (String,String)
nameValPair = do r1 <- itemName
cfws
r2 <- itemValue
return (r1,r2)
<?> "a name/value pair"
itemName :: CharParser a String
itemName = do r1 <- alpha
r2 <- many $ choice [ char '-', alpha, digit ]
return (r1 : r2)
<?> "name of a name/value pair"
itemValue :: CharParser a String
itemValue = choice [ try (do { r <- many1 angleAddr; return (concat r) })
, try addrSpec
, try domain
, msgId
, try atom
]
<?> "value of a name/value pair"
-- ** Optional fields (section 3.6.8)
-- |Parse an arbitrary header field and return a tuple containing the
-- 'fieldName' and 'unstructured' text of the header. The name will
-- /not/ contain the terminating colon.
optionalField :: CharParser a (String,String)
optionalField = do n <- fieldName
char ':'
b <- unstructured
crlf
return (n,b)
<?> "optional (unspecified) header line"
-- |Parse and return an arbitrary header field name. That is one or
-- more 'ftext' characters.
fieldName :: CharParser a String
fieldName = many1 ftext <?> "header line name"
-- |Match and return any ASCII character except for control
-- characters, whitespace, and \"@:@\".
ftext :: CharParser a Char
ftext = satisfy (\c -> ord c `elem` ([33..57] ++ [59..126]))
<?> "character (excluding controls, space, and ':')"
-- * Miscellaneous obsolete tokens (section 4.1)
-- |Match the obsolete \"quoted pair\" syntax, which - unlike
-- 'quotedPair ' - allowed /any/ ASCII character to be specified when
-- quoted. The parser will return both, the backslash and the actual
-- character.
obsQp :: CharParser a String
obsQp = do char '\\'
c <- satisfy (\c -> ord c `elem` [0..127])
return ['\\',c]
<?> "any quoted US-ASCII character"
-- |Match the obsolete \"text\" syntax, which - unlike 'text' - allowed
-- \"carriage returns\" and \"linefeeds\". This is really weird; you
-- better consult the RFC for details. The parser will return the
-- complete string, including those special characters.
obsText :: CharParser a String
obsText = do r1 <- many lf
r2 <- many cr
r3 <- many (do r4 <- obsChar
r5 <- many lf
r6 <- many cr
return (r4 : (r5 ++ r6)))
return (r1 ++ r2 ++ concat r3)
-- |Match and return the obsolete \"char\" syntax, which - unlike
-- 'character' - did not allow \"carriage return\" and \"linefeed\".
obsChar :: CharParser a Char
obsChar = satisfy (\c -> ord c `elem` ([0..9] ++ [11,12] ++ [14..127]))
<?> "any ASCII character except CR and LF"
-- |Match and return the obsolete \"utext\" syntax, which is identical
-- to 'obsText'.
obsUtext :: CharParser a String
obsUtext = obsText
-- |Match the obsolete \"phrase\" syntax, which - unlike 'phrase' -
-- allows dots between tokens.
obsPhrase :: CharParser a [String]
obsPhrase = do r1 <- word
r2 <- many $ choice [ word
, string "."
, do { cfws; return [] }
]
return (r1 : filter (/=[]) r2)
-- |Match a \"phrase list\" syntax and return the list of 'String's
-- that make up the phrase. In contrast to a 'phrase', the
-- 'obsPhraseList' separates the individual words by commas. This
-- syntax is - as you will have guessed - obsolete.
obsPhraseList :: CharParser a [String]
obsPhraseList = do r1 <- many1 (do r <- option [] phrase
unfold $ char ','
return (filter (/=[]) r))
r2 <- option [] phrase
return (concat r1 ++ r2)
<|> phrase
-- * Obsolete folding white space (section 4.2)
-- |Parse and return an \"obsolete fws\" token. That is at least one
-- 'wsp' character, followed by an arbitrary number (including zero)
-- of 'crlf' followed by at least one more 'wsp' character.
obsFws :: CharParser a String
obsFws = do r1 <- many1 wsp
r2 <- many (do r3 <- crlf
r4 <- many1 wsp
return (r3 ++ r4))
return (r1 ++ concat r2)
-- * Obsolete Date and Time (section 4.3)
-- |Parse a 'dayName' but allow for the obsolete folding syntax.
obsDayOfWeek :: CharParser a Day
obsDayOfWeek = unfold dayName <?> "day-of-the-week name"
-- |Parse a 'year' but allow for a two-digit number (obsolete) and the
-- obsolete folding syntax.
obsYear :: CharParser a Int
obsYear = unfold (do r <- manyN 2 digit
return (normalize (read r :: Int)))
<?> "year"
where
normalize n
| n <= 49 = 2000 + n
| n <= 999 = 1900 + n
| otherwise = n
-- |Parse a 'monthName' but allow for the obsolete folding syntax.
obsMonth :: CharParser a Month
obsMonth = between cfws cfws monthName <?> "month name"
-- |Parse a 'day' but allow for the obsolete folding syntax.
obsDay :: CharParser a Int
obsDay = unfold day <?> "day"
-- |Parse a 'hour' but allow for the obsolete folding syntax.
obsHour :: CharParser a Int
obsHour = unfold hour <?> "hour"
-- |Parse a 'minute' but allow for the obsolete folding syntax.
obsMinute :: CharParser a Int
obsMinute = unfold minute <?> "minute"
-- |Parse a 'second' but allow for the obsolete folding syntax.
obsSecond :: CharParser a Int
obsSecond = unfold second <?> "second"
-- |Match the obsolete zone names and return the appropriate offset.
obsZone :: CharParser a Int
obsZone = choice [ mkZone "UT" 0
, mkZone "GMT" 0
, mkZone "EST" (-5)
, mkZone "EDT" (-4)
, mkZone "CST" (-6)
, mkZone "CDT" (-5)
, mkZone "MST" (-7)
, mkZone "MDT" (-6)
, mkZone "PST" (-8)
, mkZone "PDT" (-7)
, do { r <- oneOf ['A'..'I']; return $ (ord r - 64) * 60*60 } <?> "military zone spec"
, do { r <- oneOf ['K'..'M']; return $ (ord r - 65) * 60*60 } <?> "military zone spec"
, do { r <- oneOf ['N'..'Y']; return $ -(ord r - 77) * 60*60 } <?> "military zone spec"
, do { char 'Z'; return 0 } <?> "military zone spec"
]
where mkZone n o = try $ do { string n; return (o*60*60) }
-- * Obsolete Addressing (section 4.4)
-- |This parser will match the \"obsolete angle address\" syntax. This
-- construct used to be known as a \"route address\" in earlier RFCs.
-- There are two differences between this construct and the
-- 'angleAddr': For one - as usual -, the obsolete form allows for
-- more liberal insertion of folding whitespace and comments.
--
-- Secondly, and more importantly, angle addresses used to allow the
-- (optional) specification of a \"route\". The newer version does not.
-- Such a routing address looks like this:
--
-- > <@example1.org,@example2.org:simons@example.org>
--
-- The parser will return a tuple that - in case of the above address -
-- looks like this:
--
-- > (["example1.org","example2.org"],"simons@example.org")
--
-- The first part contains a list of hosts that constitute the route
-- part. This list may be empty! The second part of the tuple is the
-- actual 'addrSpec' address.
obsAngleAddr :: CharParser a String
obsAngleAddr = unfold (do char '<'
_ <- option [] obsRoute
addr <- addrSpec
char '>'
return addr) -- TODO: route is lost here.
<?> "obsolete angle address"
-- |This parser parses the \"route\" part of 'obsAngleAddr' and
-- returns the list of 'String's that make up this route. Relies on
-- 'obsDomainList' for the actual parsing.
obsRoute :: CharParser a [String]
obsRoute = unfold (do { r <- obsDomainList; char ':'; return r })
<?> "route of an obsolete angle address"
-- |This parser parses a list of domain names, each of them prefaced
-- with an \"at\". Multiple names are separated by a comma. The list of
-- 'domain's is returned - and may be empty.
obsDomainList :: CharParser a [String]
obsDomainList = do char '@'
r1 <- domain
r2 <- many (do cfws <|> string ","
optional cfws
char '@'
domain)
return (r1 : r2)
<?> "route of an obsolete angle address"
-- |Parse the obsolete syntax of a 'localPart', which allowed for
-- more liberal insertion of folding whitespace and comments. The
-- actual string is returned.
obsLocalPart :: CharParser a String
obsLocalPart = do r1 <- word
r2 <- many (do string "."
r <- word
return ('.' : r))
return (r1 ++ concat r2)
<?> "local part of an address"
-- |Parse the obsolete syntax of a 'domain', which allowed for more
-- liberal insertion of folding whitespace and comments. The actual
-- string is returned.
obsDomain :: CharParser a String
obsDomain = do r1 <- atom
r2 <- many (do string "."
r <- atom
return ('.' : r))
return (r1 ++ concat r2)
<?> "domain part of an address"
-- |This parser will match the obsolete syntax for a 'mailboxList'.
-- This one is quite weird: An 'obsMboxList' contains an arbitrary
-- number of 'mailbox'es - including none -, which are separated by
-- commas. But you may have multiple consecutive commas without giving
-- a 'mailbox'. You may also have a valid 'obsMboxList' that
-- contains /no/ 'mailbox' at all. On the other hand, you /must/ have
-- at least one comma.
--
-- So, this input is perfectly valid:
--
-- > ","
--
-- But this one is - contrary to all intuition - not:
--
-- > "simons@example.org"
--
-- Strange, isn't it?
obsMboxList :: CharParser a [NameAddr]
obsMboxList = do r1 <- many1 (try (do r <- maybeOption mailbox
unfold $ char ','
return r))
r2 <- maybeOption mailbox
return [x | Just x <- r1 ++ [r2]]
<?> "obsolete syntax for a list of mailboxes"
-- |This parser is identical to 'obsMboxList' but parses a list of
-- 'address'es rather than 'mailbox'es. The main difference is that an
-- 'address' may contain 'group's. Please note that as of now, the
-- parser will return a simple list of addresses; the grouping
-- information is lost.
obsAddrList :: CharParser a [NameAddr]
obsAddrList = do r1 <- many1 (try (do r <- maybeOption address
optional cfws
char ','
optional cfws
return r))
r2 <- maybeOption address
return (concat [x | Just x <- r1 ++ [r2]])
<?> "obsolete syntax for a list of addresses"
-- * Obsolete header fields (section 4.5)
obsFields :: GenParser Char a [Field]
obsFields = many ( try (do { r <- obsFrom; return (From r) })
<|> try (do { r <- obsSender; return (Sender r) })
<|> try (do { r <- obsReturn; return (ReturnPath r) })
<|> try (do { r <- obsReplyTo; return (ReplyTo r) })
<|> try (do { r <- obsTo; return (To r) })
<|> try (do { r <- obsCc; return (Cc r) })
<|> try (do { r <- obsBcc; return (Bcc r) })
<|> try (do { r <- obsMessageId; return (MessageID r) })
<|> try (do { r <- obsInReplyTo; return (InReplyTo r) })
<|> try (do { r <- obsReferences; return (References r) })
<|> try (do { r <- obsSubject; return (Subject r) })
<|> try (do { r <- obsComments; return (Comments r) })
<|> try (do { r <- obsKeywords; return (Keywords [r]) })
<|> try (do { r <- obsOrigDate; return (Date r) })
<|> try (do { r <- obsResentDate; return (ResentDate r) })
<|> try (do { r <- obsResentFrom; return (ResentFrom r) })
<|> try (do { r <- obsResentSend; return (ResentSender r) })
<|> try (do { r <- obsResentTo; return (ResentTo r) })
<|> try (do { r <- obsResentCc; return (ResentCc r) })
<|> try (do { r <- obsResentBcc; return (ResentBcc r) })
<|> try (do { r <- obsResentMid; return (ResentMessageID r) })
<|> try (do { r <- obsResentReply; return (ResentReplyTo r) })
<|> try (do { r <- obsReceived; return (ObsReceived r) })
-- catch all
<|> (do { (name,cont) <- obsOptional; return (OptionalField name cont) })
)
-- ** Obsolete origination date field (section 4.5.1)
-- |Parse a 'date' header line but allow for the obsolete
-- folding syntax.
obsOrigDate :: CharParser a CalendarTime
obsOrigDate = obsHeader "Date" dateTime
-- ** Obsolete originator fields (section 4.5.2)
-- |Parse a 'from' header line but allow for the obsolete
-- folding syntax.
obsFrom :: CharParser a [NameAddr]
obsFrom = obsHeader "From" mailboxList
-- |Parse a 'sender' header line but allow for the obsolete
-- folding syntax.
obsSender :: CharParser a NameAddr
obsSender = obsHeader "Sender" mailbox
-- |Parse a 'replyTo' header line but allow for the obsolete
-- folding syntax.
obsReplyTo :: CharParser a [NameAddr]
obsReplyTo = obsHeader "Reply-To" mailboxList
-- ** Obsolete destination address fields (section 4.5.3)
-- |Parse a 'to' header line but allow for the obsolete
-- folding syntax.
obsTo :: CharParser a [NameAddr]
obsTo = obsHeader "To" addressList
-- |Parse a 'cc' header line but allow for the obsolete
-- folding syntax.
obsCc :: CharParser a [NameAddr]
obsCc = obsHeader "Cc" addressList
-- |Parse a 'bcc' header line but allow for the obsolete
-- folding syntax.
obsBcc :: CharParser a [NameAddr]
obsBcc = header "Bcc" ( try addressList
<|> do { optional cfws; return [] }
)
-- ** Obsolete identification fields (section 4.5.4)
-- |Parse a 'messageId' header line but allow for the obsolete
-- folding syntax.
obsMessageId :: CharParser a String
obsMessageId = obsHeader "Message-ID" msgId
-- |Parse an 'inReplyTo' header line but allow for the obsolete
-- folding and the obsolete phrase syntax.
obsInReplyTo :: CharParser a [String]
obsInReplyTo = obsHeader "In-Reply-To" (do r <- many ( do {phrase; return [] }
<|> msgId
)
return (filter (/=[]) r))
-- |Parse a 'references' header line but allow for the obsolete
-- folding and the obsolete phrase syntax.
obsReferences :: CharParser a [String]
obsReferences = obsHeader "References" (do r <- many (do { phrase; return [] }
<|> msgId
)
return (filter (/=[]) r))
-- |Parses the \"left part\" of a message ID, but allows the obsolete
-- syntax, which is identical to a 'localPart'.
obsIdLeft :: CharParser a String
obsIdLeft = localPart <?> "left part of an message ID"
-- |Parses the \"right part\" of a message ID, but allows the obsolete
-- syntax, which is identical to a 'domain'.
obsIdRight :: CharParser a String
obsIdRight = domain <?> "right part of an message ID"
-- ** Obsolete informational fields (section 4.5.5)
-- |Parse a 'subject' header line but allow for the obsolete
-- folding syntax.
obsSubject :: CharParser a String
obsSubject = obsHeader "Subject" unstructured
-- |Parse a 'comments' header line but allow for the obsolete
-- folding syntax.
obsComments :: CharParser a String
obsComments = obsHeader "Comments" unstructured
-- |Parse a 'keywords' header line but allow for the obsolete
-- folding syntax. Also, this parser accepts 'obsPhraseList'.
obsKeywords :: CharParser a [String]
obsKeywords = obsHeader "Keywords" obsPhraseList
-- ** Obsolete resent fields (section 4.5.6)
-- |Parse a 'resentFrom' header line but allow for the obsolete
-- folding syntax.
obsResentFrom :: CharParser a [NameAddr]
obsResentFrom = obsHeader "Resent-From" mailboxList
-- |Parse a 'resentSender' header line but allow for the obsolete
-- folding syntax.
obsResentSend :: CharParser a NameAddr
obsResentSend = obsHeader "Resent-Sender" mailbox
-- |Parse a 'resentDate' header line but allow for the obsolete
-- folding syntax.
obsResentDate :: CharParser a CalendarTime
obsResentDate = obsHeader "Resent-Date" dateTime
-- |Parse a 'resentTo' header line but allow for the obsolete
-- folding syntax.
obsResentTo :: CharParser a [NameAddr]
obsResentTo = obsHeader "Resent-To" mailboxList
-- |Parse a 'resentCc' header line but allow for the obsolete
-- folding syntax.
obsResentCc :: CharParser a [NameAddr]
obsResentCc = obsHeader "Resent-Cc" mailboxList
-- |Parse a 'resentBcc' header line but allow for the obsolete
-- folding syntax.
obsResentBcc :: CharParser a [NameAddr]
obsResentBcc = obsHeader "Bcc" ( try addressList
<|> do { optional cfws; return [] }
)
-- |Parse a 'resentMsgId' header line but allow for the obsolete
-- folding syntax.
obsResentMid :: CharParser a String
obsResentMid = obsHeader "Resent-Message-ID" msgId
-- |Parse a @Resent-Reply-To@ header line but allow for the
-- obsolete folding syntax.
obsResentReply :: CharParser a [NameAddr]
obsResentReply = obsHeader "Resent-Reply-To" addressList
-- ** Obsolete trace fields (section 4.5.7)
obsReturn :: CharParser a String
obsReturn = obsHeader "Return-Path" path
obsReceived :: CharParser a [(String, String)]
obsReceived = obsHeader "Received" nameValList
-- |Match 'obsAngleAddr'.
obsPath :: CharParser a String
obsPath = obsAngleAddr
-- |This parser is identical to 'optionalField' but allows the more
-- liberal line-folding syntax between the \"fieldName\" and the \"field
-- text\".
obsOptional :: CharParser a (String,String)
obsOptional = do n <- fieldName
many wsp
char ':'
b <- unstructured
crlf
return (n,b)
<?> "optional (unspecified) header line"