content: --- * -*- outline-regexp:"--- \\*"; -*-
  --- ** doc
  -- In Emacs, use TAB on lines beginning with "-- *" to collapse/expand sections.
  {-|
  
  File reading/parsing utilities used by multiple readers, and a good
  amount of the parsers for journal format, to avoid import cycles
  when JournalReader imports other readers.
  
  Some of these might belong in Hledger.Read.JournalReader or Hledger.Read.
  
  -}
  
  --- ** language
  {-# LANGUAGE BangPatterns        #-}
  {-# LANGUAGE CPP                 #-}
  {-# LANGUAGE FlexibleContexts    #-}
  {-# LANGUAGE LambdaCase          #-}
  {-# LANGUAGE NamedFieldPuns      #-}
  {-# LANGUAGE NoMonoLocalBinds    #-}
  {-# LANGUAGE OverloadedStrings   #-}
  {-# LANGUAGE Rank2Types          #-}
  {-# LANGUAGE RecordWildCards     #-}
  {-# LANGUAGE ScopedTypeVariables #-}
  {-# LANGUAGE TupleSections       #-}
  {-# LANGUAGE TypeFamilies        #-}
  {-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
  {-# HLINT ignore "Functor law" #-}
  
  --- ** exports
  module Hledger.Read.Common (
    Reader (..),
    PrefixedFilePath,
    isStdin,
    InputOpts(..),
    HasInputOpts(..),
    definputopts,
    rawOptsToInputOpts,
    handleReadFnToTextReadFn,
  
    -- * parsing utilities
    parseAndFinaliseJournal,
    initialiseAndParseJournal,
    journalFinalise,
    journalAddForecast,
    journalAddAutoPostings,
    setYear,
    getYear,
    setDefaultCommodityAndStyle,
    getDefaultCommodityAndStyle,
    getDefaultAmountStyle,
    getAmountStyle,
    addDeclaredAccountTags,
    addDeclaredAccountType,
    pushParentAccount,
    popParentAccount,
    getParentAccount,
    addAccountAlias,
    getAccountAliases,
    clearAccountAliases,
    journalAddFile,
  
    -- * parsers
    -- ** transaction bits
    statusp,
    codep,
    descriptionp,
  
    -- ** dates
    datep,
    datetimep,
    secondarydatep,
  
    -- ** account names
    modifiedaccountnamep,
    accountnamep,
    accountnamenosemicolonp,
  
    -- ** account aliases
    accountaliasp,
  
    -- ** amounts
    spaceandamountormissingp,
    amountp,
    amountp',
    commoditysymbolp,
    costp,
    balanceassertionp,
    lotcostp,
    numberp,
    fromRawNumber,
    rawnumberp,
    parseamount,
    parseamount',
    parsemixedamount,
    parsemixedamount',
  
    -- ** comments
    isLineCommentStart,
    isSameLineCommentStart,
    multilinecommentp,
    emptyorcommentlinep,
    emptyorcommentlinep2,
    followingcommentp,
    transactioncommentp,
    commentlinetagsp,
    postingcommentp,
  
    -- ** bracketed dates
    bracketeddatetagsp,
  
    -- ** misc
    doublequotedtextp,
    noncommenttextp,
    noncommenttext1p,
    singlespacedtext1p,
    singlespacednoncommenttext1p,
    singlespacedtextsatisfying1p,
    singlespacep,
    skipNonNewlineSpaces,
    skipNonNewlineSpaces1,
    aliasesFromOpts,
  
    -- * tests
    tests_Common,
  )
  where
  
  --- ** imports
  import Control.Applicative.Permutations (runPermutation, toPermutationWithDefault)
  import Control.Monad (foldM, liftM2, when, unless, (>=>), (<=<))
  import Control.Monad.Fail qualified as Fail (fail)
  import Control.Monad.Except (ExceptT(..), liftEither, withExceptT)
  import Control.Monad.IO.Class (MonadIO, liftIO)
  import Control.Monad.State.Strict (MonadState, evalStateT, modify', get, put)
  import Control.Monad.Trans.Class (lift)
  import Data.Bifunctor (bimap, second)
  import Data.Char (digitToInt, isDigit, isSpace)
  import Data.Decimal (DecimalRaw (Decimal), Decimal)
  import Data.Either (rights)
  import Data.Function ((&))
  import Data.Functor ((<&>), ($>), void)
  import Data.List (find, genericReplicate, union)
  import Data.List.NonEmpty (NonEmpty(..))
  import Data.Maybe (catMaybes, fromMaybe, isJust, listToMaybe)
  import Data.Map qualified as M
  import Data.Semigroup qualified as Sem
  import Data.Text (Text, stripEnd)
  import Data.Text qualified as T
  import Data.Time.Calendar (Day, fromGregorianValid, toGregorian)
  import Data.Time.Clock.POSIX (getPOSIXTime)
  import Data.Time.LocalTime (LocalTime(..), TimeOfDay(..))
  import Data.Word (Word8)
  import System.FilePath (takeFileName)
  import System.IO (Handle)
  import Text.Megaparsec
  import Text.Megaparsec.Char (char, char', digitChar, newline, string)
  import Text.Megaparsec.Char.Lexer (decimal)
  
  import Hledger.Data
  import Hledger.Query (Query(..), filterQuery, parseQueryTerm, queryEndDate, queryStartDate, queryIsDate, simplifyQuery)
  import Hledger.Reports.ReportOptions (ReportOpts(..), queryFromFlags, rawOptsToReportOpts)
  import Hledger.Utils
  import Hledger.Read.InputOptions
  
  
  --- ** doctest setup
  -- $setup
  -- >>> :set -XOverloadedStrings
  
  --- ** types
  
  -- main types; a few more below
  
  -- | A hledger journal reader is a storage format name,
  -- a list of file extensions assumed to be in this format,
  -- and an IO action that reads data in this format, returning a Journal.
  --
  -- The journal parser used by the latter is also stored separately for direct use
  -- by the journal reader's includedirectivep to parse included files.
  -- The type variable m is needed for this parser.
  -- Lately it requires an InputOpts, basically to support --old-timeclock.
  data Reader m = Reader {
      -- The canonical name of the format handled by this reader. "journal", "timedot", "csv" etc.
     rFormat :: StorageFormat
      -- The file extensions recognised as containing this format.
    ,rExtensions :: [String]
      -- An IO action for reading this format, producing a journal or an error message.
      -- It accepts input options, a file path to show in error messages, and a handle to read data from.
    ,rReadFn :: InputOpts -> FilePath -> Handle -> ExceptT String IO Journal
      -- The megaparsec parser called by the above, provided separately for parsing included files.
    ,rParser :: MonadIO m => InputOpts -> ErroringJournalParser m ParsedJournal
    }
  
  instance Show (Reader m) where show r = show (rFormat r) ++ " reader"
  
  -- | A file path optionally prefixed by a reader name and colon (journal:, csv:, timedot:, etc.).
  -- The file path part can also be - meaning standard input.
  type PrefixedFilePath = FilePath
  
  -- | Is this the special file path meaning standard input ? (-, possibly prefixed)
  isStdin :: PrefixedFilePath -> Bool
  isStdin f = case splitAtElement ':' f of
    [_,"-"] -> True
    ["-"] -> True
    _ -> False
  
  -- | Parse an InputOpts from a RawOpts and a provided date.
  -- This will fail with a usage error if the forecast period expression cannot be parsed.
  rawOptsToInputOpts :: Day -> Bool -> Bool -> RawOpts -> InputOpts
  rawOptsToInputOpts day usecoloronstdout postingaccttags rawopts =
  
      let
          -- Allow/disallow implicit-cost conversion transactions, according to policy in Check.md.
          -- Disallow them if we see the --strict flag, or if we see a "balanced" argument with the "check" command,
          -- which we assume means the user is running "hledger check balanced".
          -- XXX #2377 The check was originally named "balancednoautoconversion",
          -- but later it was renamed, so this is no longer good; any command with "balanced"
          -- as an argument will also enable this check, normally enabled only in strict mode.
          noinferbalancingcosts =  -- keep synced with Check.*
               boolopt "strict" rawopts 
            || (stringopt "args" rawopts == "balanced" && stringopt "command" rawopts == "check")
  
          -- Do we really need to do all this work just to get the requested end date? This is duplicating
          -- much of reportOptsToSpec.
          ropts = rawOptsToReportOpts day usecoloronstdout rawopts
          argsquery = map fst . rights . map (parseQueryTerm day) $ querystring_ ropts
          datequery = simplifyQuery . filterQuery queryIsDate . And $ queryFromFlags ropts : argsquery
  
          txnbalancingprecision = either err id $ transactionBalancingPrecisionFromOpts rawopts
            where err e = error' $ "could not parse --txn-balancing: '" ++ e ++ "'"  -- PARTIAL:
  
          styles = either err id $ commodityStyleFromRawOpts rawopts
            where err e = error' $ "could not parse --commodity-style: '" ++ e ++ "'"  -- PARTIAL:
  
      in definputopts{
         -- files_             = listofstringopt "file" rawopts
         mformat_           = Nothing
        ,mrules_file_       = maybestringopt "rules" rawopts
        ,aliases_           = listofstringopt "alias" rawopts
        ,anon_              = boolopt "obfuscate" rawopts
        ,new_               = boolopt "new" rawopts
        ,new_save_          = True
        ,pivot_             = stringopt "pivot" rawopts
        ,forecast_          = forecastPeriodFromRawOpts day rawopts
        ,posting_account_tags_ = postingaccttags
        ,verbose_tags_      = boolopt "verbose-tags" rawopts
        ,reportspan_        = DateSpan (Exact <$> queryStartDate False datequery) (Exact <$> queryEndDate False datequery)
        ,auto_              = boolopt "auto" rawopts
        ,infer_equity_      = boolopt "infer-equity" rawopts && conversionop_ ropts /= Just ToCost
        ,infer_costs_       = boolopt "infer-costs" rawopts
        ,balancingopts_     = defbalancingopts{
                                   ignore_assertions_     = boolopt "ignore-assertions" rawopts
                                 , infer_balancing_costs_ = not noinferbalancingcosts
                                 , txn_balancing_         = txnbalancingprecision
                                 , commodity_styles_      = Just styles
                                 }
        ,strict_            = boolopt "strict" rawopts
        ,_ioDay             = day
        ,_oldtimeclock      = boolopt "oldtimeclock" rawopts
        }
  
  handleReadFnToTextReadFn :: (InputOpts -> FilePath -> Text -> ExceptT String IO Journal) -> InputOpts -> FilePath -> Handle -> ExceptT String IO Journal
  handleReadFnToTextReadFn p iopts fp =
    p iopts fp <=< lift . hGetContentsPortably Nothing
  
  -- | Get the date span from --forecast's PERIODEXPR argument, if any.
  -- This will fail with a usage error if the period expression cannot be parsed,
  -- or if it contains a report interval.
  forecastPeriodFromRawOpts :: Day -> RawOpts -> Maybe DateSpan
  forecastPeriodFromRawOpts d rawopts = do
      arg <- maybestringopt "forecast" rawopts
      let period = parsePeriodExpr d . stripquotes $ T.pack arg
      return $ if null arg then nulldatespan else either badParse (getSpan arg) period
    where
      badParse e = usageError $ "could not parse forecast period : "++customErrorBundlePretty e
      getSpan arg (interval, requestedspan) = case interval of
          NoInterval -> requestedspan
          _          -> usageError $ "--forecast's argument should not contain a report interval ("
                                   ++ show interval ++ " in \"" ++ arg ++ "\")"
  
  -- | Given the raw options, return either
  -- * if all options were successfully parsed: a map of successfully parsed commodity styles,
  -- * if one or more options failed to parse: the first option which failed to parse
  commodityStyleFromRawOpts :: RawOpts -> Either String (M.Map CommoditySymbol AmountStyle)
  commodityStyleFromRawOpts rawOpts =
    foldM (\r -> fmap (\(c,a) -> M.insert c a r) . parseCommodity) mempty optList
    where
      optList = listofstringopt "commodity-style" rawOpts
      parseCommodity optStr = case parseamount optStr of
        Left _ -> Left optStr
        Right (Amount acommodity _ astyle _) -> Right (acommodity, astyle)
  
  transactionBalancingPrecisionFromOpts :: RawOpts -> Either String TransactionBalancingPrecision
  transactionBalancingPrecisionFromOpts rawopts =
    case maybestringopt "txn-balancing" rawopts of
      Nothing      -> Right TBPExact
      Just "old"   -> Right TBPOld
      Just "exact" -> Right TBPExact
      Just s       -> Left $ s<>", should be one of: old, exact"
  
  -- | Given a parser to ParsedJournal, input options, file path and
  -- content: run the parser on the content, and finalise the result to
  -- get a Journal; or throw an error.
  parseAndFinaliseJournal :: ErroringJournalParser IO ParsedJournal -> InputOpts
                             -> FilePath -> Text -> ExceptT String IO Journal
  parseAndFinaliseJournal parser iopts f txt =
      initialiseAndParseJournal parser iopts f txt >>= journalFinalise iopts f txt
  
  -- | Given a parser to ParsedJournal, input options, file path and
  -- content: run the parser on the content. This is all steps of
  -- 'parseAndFinaliseJournal' without the finalisation step, and is used when
  -- you need to perform other actions before finalisatison, as in parsing
  -- Timeclock and Timedot files.
  initialiseAndParseJournal :: ErroringJournalParser IO ParsedJournal -> InputOpts
                            -> FilePath -> Text -> ExceptT String IO Journal
  initialiseAndParseJournal parser iopts f txt =
      prettyParseErrors $ runParserT (evalStateT parser initJournal) f txt
    where
      y = first3 . toGregorian $ _ioDay iopts
      initJournal = nulljournal{jparsedefaultyear = Just y, jincludefilestack = [f]}
      -- Flatten parse errors and final parse errors, and output each as a pretty String.
      prettyParseErrors :: ExceptT FinalParseError IO (Either (ParseErrorBundle Text HledgerParseErrorData) a)
                        -> ExceptT String IO a
      prettyParseErrors = withExceptT customErrorBundlePretty . liftEither
                      <=< withExceptT (finalErrorBundlePretty . attachSource f txt)
  
  {- HLINT ignore journalFinalise "Redundant <&>" -} -- silence this warning, the code is clearer as is
  --  note this activates TH, may slow compilation ? https://github.com/ndmitchell/hlint/blob/master/README.md#customizing-the-hints
  --
  -- | Post-process a Journal that has just been parsed or generated, in this order:
  --
  -- - add misc info (file path, read time) 
  --
  -- - reverse transactions into their original parse order
  --
  -- - apply canonical commodity styles
  --
  -- - propagate account tags to postings
  --
  -- - maybe add forecast transactions
  --
  -- - propagate account tags to postings (again to affect forecast transactions)
  --
  -- - maybe add auto postings
  --
  -- - propagate account tags to postings (again to affect auto postings)
  --
  -- - evaluate balance assignments and balance each transaction
  --
  -- - maybe check balance assertions
  --
  -- - maybe infer costs from equity postings
  --
  -- - maybe infer equity postings from costs
  --
  -- - manye infer market prices from costs
  --
  -- One correctness check (parseable) has already passed when this function is called.
  -- Up to four more are performed here:
  --
  --  - ordereddates (when enabled)
  --
  --  - assertions (when enabled)
  --
  --  - autobalanced (and with --strict, balanced ?), in the journalBalanceTransactions step.
  --
  -- Others (commodities, accounts..) are done later by journalStrictChecks.
  --
  journalFinalise :: InputOpts -> FilePath -> Text -> ParsedJournal -> ExceptT String IO Journal
  journalFinalise iopts@InputOpts{auto_,balancingopts_,infer_costs_,infer_equity_,strict_,posting_account_tags_,verbose_tags_,_ioDay} f txt pj = do
    let
      BalancingOpts{commodity_styles_, ignore_assertions_} = balancingopts_
      fname = "journalFinalise " <> takeFileName f
      lbl = lbl_ fname
      -- Some not so pleasant hacks
      -- We want to know when certain checks have been explicitly requested with the check command,
      -- but it does not run until later. For now, inspect the command line with unsafePerformIO.
      checking checkname = "check" `elem` args && checkname `elem` args where args = progArgs
      -- We will check ordered dates when "check ordereddates" is used.
      checkordereddates = checking "ordereddates"
      -- We will check balance assertions by default, unless -I is used, but always if -s or "check assertions" are used.
      checkassertions = not ignore_assertions_ || strict_ || checking "assertions"
  
    t <- liftIO getPOSIXTime
    liftEither $
      pj{jglobalcommoditystyles=fromMaybe mempty commodity_styles_}
        &   journalSetLastReadTime t                       -- save the last read time
        &   journalAddFile (f, txt)                        -- save the main file's info
        &   journalReverse                                 -- convert all lists to the order they were parsed
        &   journalAddAccountTypes                         -- build a map of all known account types
              -- XXX does not see conversion accounts generated by journalInferEquityFromCosts below, requiring a workaround in journalCheckAccounts. Do it later ?
        &   journalStyleAmounts                            -- Infer and apply commodity styles (but don't round) - should be done early
        <&> journalAddForecast verbose_tags_ (forecastPeriod iopts pj)   -- Add forecast transactions if enabled
        <&> (if posting_account_tags_ then journalPostingsAddAccountTags else id)     -- Propagate account tags to postings - unless printing a beancount journal
        >>= journalTagCostsAndEquityAndMaybeInferCosts verbose_tags_ False   -- Tag equity conversion postings and redundant costs, to help journalBalanceTransactions ignore them.
        >>= (if auto_ && not (null $ jtxnmodifiers pj)
              then journalAddAutoPostings verbose_tags_ _ioDay balancingopts_  -- Add auto postings if enabled, and account tags if needed. Does preliminary transaction balancing.
              else pure)
        -- XXX how to force debug output here ?
         -- >>= Right . dbg0With (concatMap (T.unpack.showTransaction).jtxns)
         -- >>= \j -> deepseq (concatMap (T.unpack.showTransaction).jtxns $ j) (return j)
        <&> dbg9With (lbl "amounts after styling, forecasting, auto-posting".showJournalPostingAmountsDebug)
        >>= (\j -> if checkordereddates then journalCheckOrdereddates j $> j else Right j)  -- check ordereddates before assertions. The outer parentheses are needed.
        >>= journalBalanceTransactions balancingopts_{ignore_assertions_=not checkassertions}  -- infer balance assignments and missing amounts, and maybe check balance assertions.
        <&> dbg9With (lbl "amounts after transaction-balancing".showJournalPostingAmountsDebug)
        -- <&> dbg9With (("journalFinalise amounts after styling, forecasting, auto postings, transaction balancing"<>).showJournalPostingAmountsDebug)
        >>= journalInferCommodityStyles                    -- infer commodity styles once more now that all posting amounts are present
        -- >>= Right . dbg0With (pshow.journalCommodityStyles)
        >>= (if infer_costs_  then journalTagCostsAndEquityAndMaybeInferCosts verbose_tags_ True else pure)  -- With --infer-costs, infer costs from equity postings where possible
        <&> (if infer_equity_ then journalInferEquityFromCosts verbose_tags_ else id)          -- With --infer-equity, infer equity postings from costs where possible
        <&> dbg9With (lbl "amounts after equity-inferring".showJournalPostingAmountsDebug)
        <&> journalInferMarketPricesFromTransactions       -- infer market prices from commodity-exchanging transactions
        -- <&> dbg6Msg fname  -- debug logging
        <&> dbgJournalAcctDeclOrder (fname <> ": acct decls           : ")
        <&> journalRenumberAccountDeclarations
        <&> dbgJournalAcctDeclOrder (fname <> ": acct decls renumbered: ")
  
  -- | Apply any auto posting rules to generate extra postings on this journal's transactions.
  -- With a true first argument, adds visible tags to generated postings and modified transactions.
  journalAddAutoPostings :: Bool -> Day -> BalancingOpts -> Journal -> Either String Journal
  journalAddAutoPostings verbosetags d bopts =
      -- Balance all transactions without checking balance assertions,
      journalBalanceTransactions bopts{ignore_assertions_=True}
      -- then add the auto postings
      -- (Note adding auto postings after balancing means #893b fails;
      -- adding them before balancing probably means #893a, #928, #938 fail.)
      >=> journalModifyTransactions verbosetags d
  
  -- | Generate periodic transactions from all periodic transaction rules in the journal.
  -- These transactions are added to the in-memory Journal (but not the on-disk file).
  --
  -- The start & end date for generated periodic transactions are determined in
  -- a somewhat complicated way; see the hledger manual -> Periodic transactions.
  journalAddForecast :: Bool -> Maybe DateSpan -> Journal -> Journal
  journalAddForecast _ Nothing j = j
  journalAddForecast verbosetags (Just forecastspan) j = j{jtxns = jtxns j ++ forecasttxns}
    where
      {-# HLINT ignore "Move concatMap out" #-}
      forecasttxns =
          map (txnTieKnot . transactionTransformPostings (styleAmounts $ journalCommodityStyles j))
        . filter (spanContainsDate forecastspan . tdate)
        . concatMap (\pt -> runPeriodicTransaction verbosetags pt forecastspan)
        $ jperiodictxns j
  
  setYear :: Year -> JournalParser m ()
  setYear y = modify' (\j -> j{jparsedefaultyear=Just y})
  
  getYear :: JournalParser m (Maybe Year)
  getYear = fmap jparsedefaultyear get
  
  dp :: String -> TextParser m ()
  dp = const $ return ()  -- no-op
  -- dp = dbgparse 0  -- trace parse state at this --debug level
  
  -- | Get the decimal mark that has been specified for parsing, if any
  -- (eg by the CSV decimal-mark rule, or possibly a future journal directive).
  -- Return it as an AmountStyle that amount parsers can use.
  getDecimalMarkStyle :: JournalParser m (Maybe AmountStyle)
  getDecimalMarkStyle = do
    Journal{jparsedecimalmark} <- get
    let mdecmarkStyle = (\c -> Just $ amountstyle{asdecimalmark=Just c}) =<< jparsedecimalmark
    return mdecmarkStyle
  
  setDefaultCommodityAndStyle :: (CommoditySymbol,AmountStyle) -> JournalParser m ()
  setDefaultCommodityAndStyle cs = modify' (\j -> j{jparsedefaultcommodity=Just cs})
  
  getDefaultCommodityAndStyle :: JournalParser m (Maybe (CommoditySymbol,AmountStyle))
  getDefaultCommodityAndStyle = jparsedefaultcommodity `fmap` get
  
  -- | Get amount style associated with default currency.
  --
  -- Returns 'AmountStyle' used to defined by a latest default commodity directive
  -- prior to current position within this file or its parents.
  getDefaultAmountStyle :: JournalParser m (Maybe AmountStyle)
  getDefaultAmountStyle = fmap snd <$> getDefaultCommodityAndStyle
  
  -- | Get the 'AmountStyle' declared by the most recently parsed (in the current or parent files,
  -- prior to the current position) commodity directive for the given commodity, if any.
  getAmountStyle :: CommoditySymbol -> JournalParser m (Maybe AmountStyle)
  getAmountStyle commodity = do
    Journal{jdeclaredcommodities} <- get
    let mspecificStyle = M.lookup commodity jdeclaredcommodities >>= cformat
    mdefaultStyle <- fmap snd <$> getDefaultCommodityAndStyle
    return $ listToMaybe $ catMaybes [mspecificStyle, mdefaultStyle]
  
  addDeclaredAccountTags :: AccountName -> [Tag] -> JournalParser m ()
  addDeclaredAccountTags acct atags =
    modify' (\j -> j{jdeclaredaccounttags = M.insertWith (flip union) acct atags (jdeclaredaccounttags j)})
  
  addDeclaredAccountType :: AccountName -> AccountType -> JournalParser m ()
  addDeclaredAccountType acct atype =
    modify' (\j -> j{jdeclaredaccounttypes = M.insertWith (++) atype [acct] (jdeclaredaccounttypes j)})
  
  pushParentAccount :: AccountName -> JournalParser m ()
  pushParentAccount acct = modify' (\j -> j{jparseparentaccounts = acct : jparseparentaccounts j})
  
  popParentAccount :: JournalParser m ()
  popParentAccount = do
    j <- get
    case jparseparentaccounts j of
      []       -> unexpected (Tokens ('E' :| "nd of apply account block with no beginning"))
      (_:rest) -> put j{jparseparentaccounts=rest}
  
  getParentAccount :: JournalParser m AccountName
  getParentAccount = fmap (concatAccountNames . reverse . jparseparentaccounts) get
  
  addAccountAlias :: MonadState Journal m => AccountAlias -> m ()
  addAccountAlias a = modify' (\(j@Journal{..}) -> j{jparsealiases=a:jparsealiases})
  
  getAccountAliases :: MonadState Journal m => m [AccountAlias]
  getAccountAliases = fmap jparsealiases get
  
  clearAccountAliases :: MonadState Journal m => m ()
  clearAccountAliases = modify' (\j -> j{jparsealiases=[]})
  
  -- getTransactionCount :: MonadState Journal m =>  m Integer
  -- getTransactionCount = fmap jparsetransactioncount get
  --
  -- setTransactionCount :: MonadState Journal m => Integer -> m ()
  -- setTransactionCount i = modify' (\j -> j{jparsetransactioncount=i})
  --
  -- -- | Increment the transaction index by one and return the new value.
  -- incrementTransactionCount :: MonadState Journal m => m Integer
  -- incrementTransactionCount = do
  --   modify' (\j -> j{jparsetransactioncount=jparsetransactioncount j + 1})
  --   getTransactionCount
  
  journalAddFile :: (FilePath,Text) -> Journal -> Journal
  journalAddFile f j@Journal{jfiles=fs} = j{jfiles=fs++[f]}
    -- append, unlike the other fields, even though we do a final reverse,
    -- to compensate for additional reversal due to including/monoid-concatting
  
  -- A version of `match` that is strict in the returned text
  match' :: TextParser m a -> TextParser m (Text, a)
  match' p = do
    (!txt, p') <- match p
    pure (txt, p')
  
  --- ** parsers
  --- *** transaction bits
  
  statusp :: TextParser m Status
  statusp =
    choice'
      [ skipNonNewlineSpaces >> char '*' >> return Cleared
      , skipNonNewlineSpaces >> char '!' >> return Pending
      , return Unmarked
      ]
  
  codep :: TextParser m Text
  codep = option "" $ do
    try $ do
      skipNonNewlineSpaces1
      char '('
    code <- takeWhileP Nothing $ \c -> c /= ')' && c /= '\n'
    char ')' <?> "closing bracket ')' for transaction code"
    pure code
  
  -- | Parse possibly empty text until a semicolon or newline.
  -- Whitespace is preserved (for now - perhaps helps preserve alignment 
  -- of same-line comments ?).
  descriptionp :: TextParser m Text
  descriptionp = noncommenttextp <?> "description"
  
  --- *** dates
  
  -- | Parse a date in YYYY-MM-DD format.
  -- Slash (/) and period (.) are also allowed as separators.
  -- The year may be omitted if a default year has been set.
  -- Leading zeroes may be omitted.
  datep :: JournalParser m Day
  datep = do
    mYear <- getYear
    lift $ datep' mYear
  
  datep' :: Maybe Year -> TextParser m Day
  datep' mYear = do
      startOffset <- getOffset
      d1 <- yearorintp <?> "year or month"
      sep <- datesepchar <?> "date separator"
      d2 <- decimal <?> "month or day"
      case d1 of
        Left y  -> fullDate startOffset y sep d2
        Right m -> partialDate startOffset mYear m d2
      <?> "full or partial date"
    where
      fullDate :: Int -> Year -> Char -> Month -> TextParser m Day
      fullDate startOffset year sep month = do
        sep2 <- satisfy isDateSepChar <?> "date separator"
        day <- decimal <?> "day"
        endOffset <- getOffset
        when (sep /= sep2) $ 
          customFailure $ parseErrorAtRegion startOffset endOffset $
            "This date has different separators, please use consistent separators."
        case fromGregorianValid year month day of
          Nothing -> 
            customFailure $ parseErrorAtRegion startOffset endOffset $
              "This is not a valid date, please fix it."
          Just date -> pure $! date
  
      partialDate :: Int -> Maybe Year -> Month -> MonthDay -> TextParser m Day
      partialDate startOffset myr month day = do
        endOffset <- getOffset
        case myr of
          Just year ->
            case fromGregorianValid year month day of
              Nothing -> 
                customFailure $ parseErrorAtRegion startOffset endOffset $
                  "This is not a valid date, please fix it."
              Just date -> pure $! date
  
          Nothing ->
            customFailure $ parseErrorAtRegion startOffset endOffset $
              "This partial date can not be parsed because the current year is unknown.\n"
              ++"Please make it a full date, or add a default year directive."
  
  {-# INLINABLE datep' #-}
  
  -- | Parse a date and time in YYYY-MM-DD HH:MM[:SS][+-ZZZZ] format.
  -- Slash (/) and period (.) are also allowed as date separators.
  -- The year may be omitted if a default year has been set.
  -- Seconds are optional.
  -- The timezone is optional and ignored (the time is always interpreted as a local time).
  -- Leading zeroes may be omitted (except in a timezone).
  datetimep :: JournalParser m LocalTime
  datetimep = do
    mYear <- getYear
    lift $ datetimep' mYear
  
  datetimep' :: Maybe Year -> TextParser m LocalTime
  datetimep' mYear = do
    day <- datep' mYear
    skipNonNewlineSpaces1
    time <- timeOfDay
    optional timeZone -- ignoring time zones
    pure $ LocalTime day time
  
    where
      timeOfDay :: TextParser m TimeOfDay
      timeOfDay = do
        off1 <- getOffset
        h' <- twoDigitDecimal <?> "hour"
        off2 <- getOffset
        unless (h' >= 0 && h' <= 23) $ customFailure $
          parseErrorAtRegion off1 off2 "invalid time (bad hour)"
  
        char ':' <?> "':' (hour-minute separator)"
        off3 <- getOffset
        m' <- twoDigitDecimal <?> "minute"
        off4 <- getOffset
        unless (m' >= 0 && m' <= 59) $ customFailure $
          parseErrorAtRegion off3 off4 "invalid time (bad minute)"
  
        s' <- option 0 $ do
          char ':' <?> "':' (minute-second separator)"
          off5 <- getOffset
          s' <- twoDigitDecimal <?> "second"
          off6 <- getOffset
          unless (s' >= 0 && s' <= 59) $ customFailure $
            parseErrorAtRegion off5 off6 "invalid time (bad second)"
            -- we do not support leap seconds
          pure s'
  
        pure $ TimeOfDay h' m' (fromIntegral s')
  
      twoDigitDecimal :: TextParser m Int
      twoDigitDecimal = do
        d1 <- digitToInt <$> digitChar
        d2 <- digitToInt <$> (digitChar <?> "a second digit")
        pure $ d1*10 + d2
  
      timeZone :: TextParser m String
      timeZone = do
        plusminus <- satisfy $ \c -> c == '-' || c == '+'
        fourDigits <- count 4 (digitChar <?> "a digit (for a time zone)")
        pure $ plusminus:fourDigits
  
  secondarydatep :: Day -> TextParser m Day
  secondarydatep primaryDate = char '=' *> datep' (Just primaryYear)
    where primaryYear = first3 $ toGregorian primaryDate
  
  -- | Parse a year number or an Int. Years must contain at least four
  -- digits.
  yearorintp :: TextParser m (Either Year Int)
  yearorintp = do
      yearOrMonth <- takeWhile1P (Just "digit") isDigit
      let n = readDecimal yearOrMonth
      return $ if T.length yearOrMonth >= 4 then Left n else Right (fromInteger n)
  
  --- *** account names
  
  -- | Parse an account name plus one following space if present (see accountnamep);
  -- then apply any parent account prefix and/or account aliases currently in effect,
  -- in that order. Ie first add the parent account prefix, then rewrite with aliases.
  -- This calls error if any account alias with an invalid regular expression exists.
  -- The flag says whether account names may include semicolons; currently account names
  -- in journal format may, but account names in timeclock/timedot formats may not.
  modifiedaccountnamep :: Bool -> JournalParser m AccountName
  modifiedaccountnamep allowsemicolon = do
    parent  <- getParentAccount
    als     <- getAccountAliases
    -- off1    <- getOffset
    a       <- lift $ if allowsemicolon then accountnamep else accountnamenosemicolonp
    -- off2    <- getOffset
    -- XXX or accountNameApplyAliasesMemo ? doesn't seem to make a difference (retest that function)
    case accountNameApplyAliases als $ joinAccountNames parent a of
      Right a' -> return $! a'
      -- should not happen, regexaliasp will have displayed a better error already:
      -- (XXX why does customFailure cause error to be displayed there, but not here ?)
      -- Left e  -> customFailure $! parseErrorAtRegion off1 off2 err
      Left e   -> error' err  -- PARTIAL:
        where
          err = "problem in account alias applied to "++T.unpack a++": "++e
  
  -- | Parse an account name, plus one following space if present.
  -- Account names have one or more parts separated by the account separator character,
  -- and are terminated by two or more spaces (or end of input).
  -- Each part is at least one character long, may have single spaces inside it, and starts with a non-whitespace.
  -- (We should have required them to start with an alphanumeric, but didn't.)
  -- Note, this means account names can contain all kinds of punctuation, including ; which usually starts a following comment.
  -- Parent parsers usually remove the following comment before using this parser.
  accountnamep :: TextParser m AccountName
  accountnamep = singlespacedtext1p
  
  -- Like accountnamep, but stops parsing if it reaches a semicolon.
  accountnamenosemicolonp :: TextParser m AccountName
  accountnamenosemicolonp = singlespacednoncommenttext1p
  
  -- | Parse a single line of possibly empty text enclosed in double quotes.
  doublequotedtextp :: TextParser m Text
  doublequotedtextp = between (char '"') (char '"') $
    takeWhileP Nothing $ \c -> not $ isNewline c || c == '"'
  
  -- | Parse possibly empty text, including whitespace, 
  -- until a comment start (semicolon) or newline.
  noncommenttextp :: TextParser m T.Text
  noncommenttextp = takeWhileP Nothing (\c -> not $ isSameLineCommentStart c || isNewline c)
  
  -- | Parse non-empty text, including whitespace, 
  -- until a comment start (semicolon) or newline.
  noncommenttext1p :: TextParser m T.Text
  noncommenttext1p = takeWhile1P Nothing (\c -> not $ isSameLineCommentStart c || isNewline c)
  
  -- | Parse non-empty, single-spaced text starting and ending with non-whitespace,
  -- until a double space or newline.
  singlespacedtext1p :: TextParser m T.Text
  singlespacedtext1p = singlespacedtextsatisfying1p (const True)
  
  -- | Parse non-empty, single-spaced text starting and ending with non-whitespace,
  -- until a comment start (semicolon), double space, or newline.
  singlespacednoncommenttext1p :: TextParser m T.Text
  singlespacednoncommenttext1p = singlespacedtextsatisfying1p (not . isSameLineCommentStart)
  
  -- | Parse non-empty, single-spaced text starting and ending with non-whitespace,
  -- where all characters satisfy the given predicate.
  singlespacedtextsatisfying1p :: (Char -> Bool) -> TextParser m T.Text
  singlespacedtextsatisfying1p f = do
    firstPart <- partp
    otherParts <- many $ try $ singlespacep *> partp
    pure $! T.unwords $ firstPart : otherParts
    where
      partp = takeWhile1P Nothing (\c -> f c && not (isSpace c))
  
  -- | Parse one non-newline whitespace character that is not followed by another one.
  singlespacep :: TextParser m ()
  singlespacep = spacenonewline *> notFollowedBy spacenonewline
  
  --- *** amounts
  
  -- | Parse whitespace then an amount, or return the special "missing" marker amount.
  spaceandamountormissingp :: JournalParser m MixedAmount
  spaceandamountormissingp =
    option missingmixedamt $ try $ do
      lift $ skipNonNewlineSpaces1
      mixedAmount <$> amountp
  
  -- | Parse a single-commodity amount, applying the default commodity if there is no commodity symbol;
  -- optionally followed by, in any order:
  -- a Ledger-style cost, Ledger-style valuation expression, and/or Ledger-style cost basis, which is one or more of
  -- lot cost, lot date, and/or lot note (we loosely call this triple the lot's cost basis).
  -- The cost basis makes it a lot rather than just an amount. Both cost basis info and valuation expression
  -- are discarded for now.
  -- The main amount's sign is significant; here are the possibilities and their interpretation.
  -- Also imagine an optional VALUATIONEXPR added to any of these (omitted for clarity):
  -- @
  --
  --   AMT                         -- acquiring an amount
  --   AMT COST                    -- acquiring an amount at some cost
  --   AMT COST COSTBASIS          -- acquiring a lot at some cost, saving its cost basis
  --   AMT COSTBASIS COST          -- like the above
  --   AMT COSTBASIS               -- like the above with cost same as the cost basis
  --
  --  -AMT                         -- releasing an amount
  --  -AMT SELLPRICE               -- releasing an amount at some selling price
  --  -AMT SELLPRICE COSTBASISSEL  -- releasing a lot at some selling price, selecting it by its cost basis
  --  -AMT COSTBASISSEL SELLPRICE  -- like the above
  --  -AMT COSTBASISSEL            -- like the above with selling price same as the selected lot's cost basis amount
  --
  -- COST/SELLPRICE can be @ UNITAMT, @@ TOTALAMT, (@) UNITAMT, or (@@) TOTALAMT. The () are ignored.
  -- COSTBASIS    is one or more of {LOTCOST}, [LOTDATE], (LOTNOTE), in any order, with LOTCOST defaulting to COST.
  -- COSTBASISSEL is one or more of {LOTCOST}, [LOTDATE], (LOTNOTE), in any order.
  -- {LOTCOST} can be {UNITAMT}, {{TOTALAMT}}, {=UNITAMT}, or {{=TOTALAMT}}. The = is ignored.
  -- VALUATIONEXPR can be ((VALUE AMOUNT)) or ((VALUE FUNCTION)).
  --
  -- @
  -- Ledger amount syntax is really complex.
  -- Rule of thumb: curly braces, parentheses, and/or square brackets
  -- in an amount means a Ledger-style cost basis is involved.
  --
  -- To parse an amount's numeric quantity we need to know which character 
  -- represents a decimal mark. We find it in one of three ways:
  --
  -- 1. If a decimal mark has been set explicitly in the journal parse state, 
  --    we use that
  --
  -- 2. Or if the journal has a commodity declaration for the amount's commodity,
  --    we get the decimal mark from  that
  --
  -- 3. Otherwise we will parse any valid decimal mark appearing in the
  --    number, as long as the number appears well formed.
  --    (This means we handle files with any supported decimal mark without configuration,
  --    but it also allows different decimal marks in  different amounts,
  --    which is a bit too loose. There's an open issue.)
  --
  amountp :: JournalParser m Amount
  amountp = amountp' False
  
  -- An amount with optional cost, valuation, and/or cost basis, as described above.
  -- A flag indicates whether we are parsing a multiplier amount;
  -- if not, a commodity-less amount will have the default commodity applied to it.
  amountp' :: Bool -> JournalParser m Amount
  amountp' mult =
    -- dbg "amountp'" $ 
    label "amount" $ do
    let spaces = lift $ skipNonNewlineSpaces
    amt <- simpleamountp mult <* spaces
    (mcost, _valuationexpr, _mlotcost, _mlotdate, _mlotnote) <- runPermutation $
      -- costp, valuationexprp, lotnotep all parse things beginning with parenthesis, try needed
      (,,,,) <$> toPermutationWithDefault Nothing (Just <$> try (costp amt) <* spaces)
            <*> toPermutationWithDefault Nothing (Just <$> valuationexprp <* spaces)  -- XXX no try needed here ?
            <*> toPermutationWithDefault Nothing (Just <$> lotcostp <* spaces)
            <*> toPermutationWithDefault Nothing (Just <$> lotdatep <* spaces)
            <*> toPermutationWithDefault Nothing (Just <$> lotnotep <* spaces)
    pure $ amt { acost = mcost }
  
  -- An amount with optional cost, but no cost basis.
  amountnobasisp :: JournalParser m Amount
  amountnobasisp =
    -- dbg "amountnobasisp" $ 
    label "amount" $ do
    let spaces = lift $ skipNonNewlineSpaces
    amt <- simpleamountp False
    spaces
    mprice <- optional $ costp amt <* spaces
    pure $ amt { acost = mprice }
  
  -- An amount with no cost or cost basis.
  -- A flag indicates whether we are parsing a multiplier amount;
  -- if not, a commodity-less amount will have the default commodity applied to it.
  simpleamountp :: Bool -> JournalParser m Amount
  simpleamountp mult = 
    -- dbg "simpleamountp" $
    do
    sign <- lift signp
    leftsymbolamountp sign <|> rightornosymbolamountp sign
  
    where
    -- An amount with commodity symbol on the left.
    leftsymbolamountp :: (Decimal -> Decimal) -> JournalParser m Amount
    leftsymbolamountp sign = label "amount" $ do
      c <- lift commoditysymbolp
      mdecmarkStyle <- getDecimalMarkStyle
      mcommodityStyle <- getAmountStyle c
      -- XXX amounts of this commodity in periodic transaction rules and auto posting rules ? #1461
      let suggestedStyle = mdecmarkStyle <|> mcommodityStyle
      commodityspaced <- lift skipNonNewlineSpaces'
      sign2 <- lift $ signp
      offBeforeNum <- getOffset
      ambiguousRawNum <- lift rawnumberp
      mExponent <- lift $ optional $ try exponentp
      offAfterNum <- getOffset
      let numRegion = (offBeforeNum, offAfterNum)
      (q,prec,mdec,mgrps) <- lift $ interpretNumber numRegion suggestedStyle ambiguousRawNum mExponent
      let s = amountstyle{ascommodityside=L, ascommodityspaced=commodityspaced, asprecision=prec, asdecimalmark=mdec, asdigitgroups=mgrps}
      return nullamt{acommodity=c, aquantity=sign (sign2 q), astyle=s, acost=Nothing}
  
    -- An amount with commodity symbol on the right or no commodity symbol.
    -- A no-symbol amount will have the default commodity applied to it
    -- unless we are parsing a multiplier amount (*AMT).
    rightornosymbolamountp :: (Decimal -> Decimal) -> JournalParser m Amount
    rightornosymbolamountp sign = label "amount" $ do
      offBeforeNum <- getOffset
      ambiguousRawNum <- lift rawnumberp
      mExponent <- lift $ optional $ try exponentp
      offAfterNum <- getOffset
      let numRegion = (offBeforeNum, offAfterNum)
      mSpaceAndCommodity <- lift $ optional $ try $ (,) <$> skipNonNewlineSpaces' <*> commoditysymbolp
      case mSpaceAndCommodity of
        -- right symbol amount
        Just (commodityspaced, c) -> do
          mdecmarkStyle <- getDecimalMarkStyle
          mcommodityStyle <- getAmountStyle c
          -- XXX amounts of this commodity in periodic transaction rules and auto posting rules ? #1461
          let msuggestedStyle = mdecmarkStyle <|> mcommodityStyle
          (q,prec,mdec,mgrps) <- lift $ interpretNumber numRegion msuggestedStyle ambiguousRawNum mExponent
          let s = amountstyle{ascommodityside=R, ascommodityspaced=commodityspaced, asprecision=prec, asdecimalmark=mdec, asdigitgroups=mgrps}
          return nullamt{acommodity=c, aquantity=sign q, astyle=s, acost=Nothing}
        -- no symbol amount
        Nothing -> do
          -- look for a number style to use when parsing, based on
          -- these things we've already parsed, in this order of preference:
          mdecmarkStyle   <- getDecimalMarkStyle   -- a decimal-mark CSV rule
          mcommodityStyle <- getAmountStyle ""     -- a commodity directive for the no-symbol commodity
          mdefaultStyle   <- getDefaultAmountStyle -- a D default commodity directive
          -- XXX no-symbol amounts in periodic transaction rules and auto posting rules ? #1461
          let msuggestedStyle = mdecmarkStyle <|> mcommodityStyle <|> mdefaultStyle
          (q,prec,mdec,mgrps) <- lift $ interpretNumber numRegion msuggestedStyle ambiguousRawNum mExponent
          -- if a default commodity has been set, apply it and its style to this amount
          -- (unless it's a multiplier in an automated posting)
          defcs <- getDefaultCommodityAndStyle
          let (c,s) = case (mult, defcs) of
                (False, Just (defc,defs)) -> (defc, defs{asprecision=max (asprecision defs) prec})
                _ -> ("", amountstyle{asprecision=prec, asdecimalmark=mdec, asdigitgroups=mgrps})
          return nullamt{acommodity=c, aquantity=sign q, astyle=s, acost=Nothing}
  
    -- For reducing code duplication. Doesn't parse anything. Has the type
    -- of a parser only in order to throw parse errors (for convenience).
    interpretNumber
      :: (Int, Int) -- offsets
      -> Maybe AmountStyle
      -> Either AmbiguousNumber RawNumber
      -> Maybe Integer
      -> TextParser m (Quantity, AmountPrecision, Maybe Char, Maybe DigitGroupStyle)
    interpretNumber posRegion msuggestedStyle ambiguousNum mExp =
      let rawNum = either (disambiguateNumber msuggestedStyle) id ambiguousNum
      in  case fromRawNumber rawNum mExp of
            Left errMsg -> customFailure $
                             uncurry parseErrorAtRegion posRegion errMsg
            Right (q,p,d,g) -> pure (q, Precision p, d, g)
  
  -- | Try to parse a single-commodity amount from a string
  parseamount :: String -> Either HledgerParseErrors Amount
  parseamount s = runParser (evalStateT (amountp <* eof) nulljournal) "" (T.pack s)
  
  -- | Parse a single-commodity amount from a string, or get an error.
  parseamount' :: String -> Amount
  parseamount' s =
    case parseamount s of
      Right amt -> amt
      Left err  -> error' $ show err  -- PARTIAL: XXX should throwError
  
  -- | Like parseamount', but returns a MixedAmount.
  parsemixedamount :: String -> Either HledgerParseErrors MixedAmount
  parsemixedamount = fmap mixedAmount . parseamount
  
  -- | Like parseamount', but returns a MixedAmount.
  parsemixedamount' :: String -> MixedAmount
  parsemixedamount' = mixedAmount . parseamount'
  
  -- | Parse a minus or plus sign followed by zero or more spaces,
  -- or nothing, returning a function that negates or does nothing.
  signp :: Num a => TextParser m (a -> a)
  signp = ((char '-' $> negate <|> char '+' $> id) <* skipNonNewlineSpaces) <|> pure id
  
  commoditysymbolp :: TextParser m CommoditySymbol
  commoditysymbolp =
    quotedcommoditysymbolp <|> simplecommoditysymbolp <?> "commodity symbol"
  
  quotedcommoditysymbolp :: TextParser m CommoditySymbol
  quotedcommoditysymbolp =
    between (char '"') (char '"') $ takeWhileP Nothing f
    where f c = c /= ';' && c /= '\n' && c /= '\"'
  
  simplecommoditysymbolp :: TextParser m CommoditySymbol
  simplecommoditysymbolp = takeWhile1P Nothing (not . isNonsimpleCommodityChar)
  
  -- | Ledger-style cost notation:
  -- @ UNITAMT, @@ TOTALAMT, (@) UNITAMT, or (@@) TOTALAMT. The () are ignored.
  costp :: Amount -> JournalParser m AmountCost
  costp baseAmt =
    -- dbg "costp" $
    label "transaction price" $ do
    -- https://www.ledger-cli.org/3.0/doc/ledger3.html#Virtual-posting-costs
    parenthesised <- option False $ char '(' >> pure True
    char '@'
    totalCost <- char '@' $> True <|> pure False
    when parenthesised $ void $ char ')'
  
    lift skipNonNewlineSpaces
    priceAmount <- simpleamountp False -- <?> "unpriced amount (specifying a price)"
  
    let amtsign' = signum $ aquantity baseAmt
        amtsign  = if amtsign' == 0 then 1 else amtsign'
  
    pure $ if totalCost
              then TotalCost priceAmount{aquantity=amtsign * aquantity priceAmount}
              else UnitCost  priceAmount
  
  -- | A valuation function or value can be written in double parentheses after an amount.
  valuationexprp :: JournalParser m ()
  valuationexprp =
    -- dbg "valuationexprp" $
    label "valuation expression" $ do
    string "(("
    _ <- T.strip . T.pack <$> (many $ noneOf [')','\n'])  -- XXX other line endings ?
    string "))"
    return ()
  
  balanceassertionp :: JournalParser m BalanceAssertion
  balanceassertionp = do
    sourcepos <- getSourcePos
    char '='
    istotal <- fmap isJust $ optional $ try $ char '='
    isinclusive <- fmap isJust $ optional $ try $ char '*'
    lift skipNonNewlineSpaces
    -- this amount can have a cost, but not a cost basis.
    -- balance assertions ignore it, but balance assignments will use it
    a <- amountnobasisp <?> "amount (for a balance assertion or assignment)"
    return BalanceAssertion
      { baamount    = a
      , batotal     = istotal
      , bainclusive = isinclusive
      , baposition  = sourcepos
      }
  
  -- Parse a Ledger-style lot cost,
  -- {UNITCOST} or {{TOTALCOST}} or {=FIXEDUNITCOST} or {{=FIXEDTOTALCOST}} or {},
  -- and discard it.
  lotcostp :: JournalParser m ()
  lotcostp =
    -- dbg "lotcostp" $
    label "ledger-style lot cost" $ do
    char '{'
    doublebrace <- option False $ char '{' >> pure True
    lift skipNonNewlineSpaces
    _fixed <- fmap isJust $ optional $ char '='
    lift skipNonNewlineSpaces
    _a <- option 0 $ simpleamountp False
    lift skipNonNewlineSpaces
    char '}'
    when (doublebrace) $ void $ char '}'
  
  -- Parse a Ledger-style [LOTDATE], and discard it.
  lotdatep :: JournalParser m ()
  lotdatep =
    -- dbg "lotdatep" $
    label "ledger-style lot date" $ do
    char '['
    lift skipNonNewlineSpaces
    _d <- datep
    lift skipNonNewlineSpaces
    char ']'
    return ()
  
  -- Parse a Ledger-style (LOT NOTE), and discard it.
  lotnotep :: JournalParser m ()
  lotnotep =
    -- dbg "lotnotep" $
    label "ledger-style lot note" $ do
    char '('
    lift skipNonNewlineSpaces
    _note <- stripEnd . T.pack <$> (many $ noneOf [')','\n'])  -- XXX other line endings ?
    char ')'
    return ()
  
  -- | Parse a string representation of a number for its value and display
  -- attributes.
  --
  -- Some international number formats are accepted, eg either period or comma
  -- may be used for the decimal mark, and the other of these may be used for
  -- separating digit groups in the integer part. See
  -- http://en.wikipedia.org/wiki/Decimal_separator for more examples.
  --
  -- This returns: the parsed numeric value, the precision (number of digits
  -- seen following the decimal mark), the decimal mark character used if any,
  -- and the digit group style if any.
  --
  numberp :: Maybe AmountStyle -> TextParser m (Quantity, Word8, Maybe Char, Maybe DigitGroupStyle)
  numberp suggestedStyle = label "number" $ do
      -- a number is an optional sign followed by a sequence of digits possibly
      -- interspersed with periods, commas, or both
      -- dbgparse 0 "numberp"
      sign <- signp
      rawNum <- either (disambiguateNumber suggestedStyle) id <$> rawnumberp
      mExp <- optional $ try $ exponentp
      dbg7 "numberp suggestedStyle" suggestedStyle `seq` return ()
      case dbg7 "numberp quantity,precision,mdecimalpoint,mgrps"
             $ fromRawNumber rawNum mExp of
        Left errMsg -> Fail.fail errMsg
        Right (q, p, d, g) -> pure (sign q, p, d, g)
  
  exponentp :: TextParser m Integer
  exponentp = char' 'e' *> signp <*> decimal <?> "exponent"
  
  -- | Interpret a raw number as a decimal number.
  --
  -- Returns:
  -- - the decimal number
  -- - the precision (number of digits after the decimal point)
  -- - the decimal point character, if any
  -- - the digit group style, if any (digit group character and sizes of digit groups)
  fromRawNumber
    :: RawNumber
    -> Maybe Integer
    -> Either String
              (Quantity, Word8, Maybe Char, Maybe DigitGroupStyle)
  fromRawNumber (WithSeparators{}) (Just _) =
      Left "invalid number: digit separators and exponents may not be used together"
  fromRawNumber raw mExp = do
      (quantity, precision) <- toQuantity (fromMaybe 0 mExp) (digitGroup raw) (decimalGroup raw)
      return (quantity, precision, mDecPt raw, digitGroupStyle raw)
    where
      toQuantity :: Integer -> DigitGrp -> DigitGrp -> Either String (Quantity, Word8)
      toQuantity e preDecimalGrp postDecimalGrp
        | precision < 0   = Right (Decimal 0 (digitGrpNum * 10^(-precision)), 0)
        | precision < 256 = Right (Decimal precision8 digitGrpNum, precision8)
        | otherwise = Left "invalid number: numbers with more than 255 decimal places are currently not supported"
        where
          digitGrpNum = digitGroupNumber $ preDecimalGrp <> postDecimalGrp
          precision   = toInteger (digitGroupLength postDecimalGrp) - e
          precision8  = fromIntegral precision :: Word8
  
      mDecPt (NoSeparators _ mDecimals)           = fst <$> mDecimals
      mDecPt (WithSeparators _ _ mDecimals)       = fst <$> mDecimals
      decimalGroup (NoSeparators _ mDecimals)     = maybe mempty snd mDecimals
      decimalGroup (WithSeparators _ _ mDecimals) = maybe mempty snd mDecimals
      digitGroup (NoSeparators digitGrp _)        = digitGrp
      digitGroup (WithSeparators _ digitGrps _)   = mconcat digitGrps
      digitGroupStyle (NoSeparators _ _)          = Nothing
      digitGroupStyle (WithSeparators sep grps _) = Just . DigitGroups sep $ groupSizes grps
  
      -- Outputs digit group sizes from least significant to most significant
      groupSizes :: [DigitGrp] -> [Word8]
      groupSizes digitGrps = reverse $ case map (fromIntegral . digitGroupLength) digitGrps of
        (a:b:cs) | a < b -> b:cs
        gs               -> gs
  
  disambiguateNumber :: Maybe AmountStyle -> AmbiguousNumber -> RawNumber
  disambiguateNumber msuggestedStyle (AmbiguousNumber grp1 sep grp2) =
    -- If present, use the suggested style to disambiguate;
    -- otherwise, assume that the separator is a decimal point where possible.
    if isDecimalMark sep &&
       maybe True (sep `isValidDecimalBy`) msuggestedStyle
    then NoSeparators grp1 (Just (sep, grp2))
    else WithSeparators sep [grp1, grp2] Nothing
    where
      isValidDecimalBy :: Char -> AmountStyle -> Bool
      isValidDecimalBy c = \case
        AmountStyle{asdecimalmark = Just d} -> d == c
        AmountStyle{asdigitgroups = Just (DigitGroups g _)} -> g /= c
        AmountStyle{asprecision = Precision 0} -> False
        _ -> True
  
  -- | Parse and interpret the structure of a number without external hints.
  -- Numbers are digit strings, possibly separated into digit groups by one
  -- of two types of separators. (1) Numbers may optionally have a decimal
  -- mark, which may be either a period or comma. (2) Numbers may
  -- optionally contain digit group marks, which must all be either a
  -- period, a comma, or a space.
  --
  -- It is our task to deduce the characters used as decimal mark and
  -- digit group mark, based on the allowed syntax. For instance, we
  -- make use of the fact that a decimal mark can occur at most once and
  -- must be to the right of all digit group marks.
  --
  -- >>> parseTest rawnumberp "1,234,567.89"
  -- Right (WithSeparators ',' ["1","234","567"] (Just ('.',"89")))
  -- >>> parseTest rawnumberp "1,000"
  -- Left (AmbiguousNumber "1" ',' "000")
  -- >>> parseTest rawnumberp "1 000"
  -- Right (WithSeparators ' ' ["1","000"] Nothing)
  --
  rawnumberp :: TextParser m (Either AmbiguousNumber RawNumber)
  rawnumberp = label "number" $ do
    rawNumber <- fmap Right leadingDecimalPt <|> leadingDigits
  
    -- Guard against mistyped numbers
    mExtraDecimalSep <- optional $ lookAhead $ satisfy isDecimalMark
    when (isJust mExtraDecimalSep) $
      Fail.fail "invalid number (invalid use of separator)"
  
    mExtraFragment <- optional $ lookAhead $ try $
      char ' ' *> getOffset <* digitChar
    case mExtraFragment of
      Just off -> customFailure $
                    parseErrorAt off "invalid number (excessive trailing digits)"
      Nothing -> pure ()
  
    return $ dbg7 "rawnumberp" rawNumber
    where
  
    leadingDecimalPt :: TextParser m RawNumber
    leadingDecimalPt = do
      decPt <- satisfy isDecimalMark
      decGrp <- digitgroupp
      pure $ NoSeparators mempty (Just (decPt, decGrp))
  
    leadingDigits :: TextParser m (Either AmbiguousNumber RawNumber)
    leadingDigits = do
      grp1 <- digitgroupp
      withSeparators grp1 <|> fmap Right (trailingDecimalPt grp1)
                          <|> pure (Right $ NoSeparators grp1 Nothing)
  
    withSeparators :: DigitGrp -> TextParser m (Either AmbiguousNumber RawNumber)
    withSeparators grp1 = do
      (sep, grp2) <- try $ (,) <$> satisfy isDigitSeparatorChar <*> digitgroupp
      grps <- many $ try $ char sep *> digitgroupp
  
      let digitGroups = grp1 : grp2 : grps
      fmap Right (withDecimalPt sep digitGroups)
        <|> pure (withoutDecimalPt grp1 sep grp2 grps)
  
    withDecimalPt :: Char -> [DigitGrp] -> TextParser m RawNumber
    withDecimalPt digitSep digitGroups = do
      decPt <- satisfy $ \c -> isDecimalMark c && c /= digitSep
      decDigitGrp <- option mempty digitgroupp
  
      pure $ WithSeparators digitSep digitGroups (Just (decPt, decDigitGrp))
  
    withoutDecimalPt
      :: DigitGrp
      -> Char
      -> DigitGrp
      -> [DigitGrp]
      -> Either AmbiguousNumber RawNumber
    withoutDecimalPt grp1 sep grp2 grps
      | null grps && isDecimalMark sep =
          Left $ AmbiguousNumber grp1 sep grp2
      | otherwise = Right $ WithSeparators sep (grp1:grp2:grps) Nothing
  
    trailingDecimalPt :: DigitGrp -> TextParser m RawNumber
    trailingDecimalPt grp1 = do
      decPt <- satisfy isDecimalMark
      pure $ NoSeparators grp1 (Just (decPt, mempty))
  
  isDigitSeparatorChar :: Char -> Bool
  isDigitSeparatorChar c = isDecimalMark c || isDigitSeparatorSpaceChar c
  
  -- | Kinds of unicode space character we accept as digit group marks.
  -- See also https://en.wikipedia.org/wiki/Decimal_separator#Digit_grouping .
  isDigitSeparatorSpaceChar :: Char -> Bool
  isDigitSeparatorSpaceChar c =
       c == ' '  -- space
    || c == ' '  -- no-break space
    || c == ' '  -- en space
    || c == ' '  -- em space
    || c == ' '  -- punctuation space
    || c == ' '  -- thin space
    || c == ' '  -- narrow no-break space
    || c == ' '  -- medium mathematical space
  
  -- | Some kinds of number literal we might parse.
  data RawNumber
    = NoSeparators   DigitGrp (Maybe (Char, DigitGrp))
      -- ^ A number with no digit group marks (eg 100),
      --   or with a leading or trailing comma or period
      --   which (apparently) we interpret as a decimal mark (like 100. or .100)
    | WithSeparators Char [DigitGrp] (Maybe (Char, DigitGrp))
      -- ^ A number with identifiable digit group marks
      --   (eg 1,000,000 or 1,000.50 or 1 000)
    deriving (Show, Eq)
  
  -- | Another kind of number literal: this one contains either a digit
  -- group separator or a decimal mark, we're not sure which (eg 1,000 or 100.50).
  data AmbiguousNumber = AmbiguousNumber DigitGrp Char DigitGrp
    deriving (Show, Eq)
  
  -- | Description of a single digit group in a number literal.
  -- "Thousands" is one well known digit grouping, but there are others.
  data DigitGrp = DigitGrp {
    digitGroupLength :: !Word,    -- ^ The number of digits in this group.
                                  -- This is Word to avoid the need to do overflow
                                  -- checking for the Semigroup instance of DigitGrp.
    digitGroupNumber :: !Integer  -- ^ The natural number formed by this group's digits. This should always be positive.
  } deriving (Eq)
  
  -- | A custom show instance, showing digit groups as the parser saw them.
  instance Show DigitGrp where
    show (DigitGrp len n) = "\"" ++ padding ++ numStr ++ "\""
      where numStr = show n
            padding = genericReplicate (toInteger len - toInteger (length numStr)) '0'
  
  instance Sem.Semigroup DigitGrp where
    DigitGrp l1 n1 <> DigitGrp l2 n2 = DigitGrp (l1 + l2) (n1 * 10^l2 + n2)
  
  instance Monoid DigitGrp where
    mempty = DigitGrp 0 0
    mappend = (Sem.<>)
  
  digitgroupp :: TextParser m DigitGrp
  digitgroupp = label "digits"
              $ makeGroup <$> takeWhile1P (Just "digit") isDigit
    where
      makeGroup = uncurry DigitGrp . T.foldl' step (0, 0)
      step (!l, !a) c = (l+1, a*10 + fromIntegral (digitToInt c))
  
  --- *** comments
  
  multilinecommentp :: TextParser m ()
  multilinecommentp = startComment *> anyLine `skipManyTill` endComment
    where
      startComment = string "comment" *> trailingSpaces
      endComment = eof <|> string "end comment" *> trailingSpaces
  
      trailingSpaces = skipNonNewlineSpaces <* newline
      anyLine = void $ takeWhileP Nothing (/='\n') *> newline
  
  {-# INLINABLE multilinecommentp #-}
  
  -- | A blank or comment line in journal format: a line that's empty or
  -- containing only whitespace or whose first non-whitespace character
  -- is semicolon, hash, or star. See also emptyorcommentlinep2.
  emptyorcommentlinep :: TextParser m ()
  emptyorcommentlinep = do
    dp "emptyorcommentlinep"
    skipNonNewlineSpaces
    skiplinecommentp <|> void newline
    where
      skiplinecommentp :: TextParser m ()
      skiplinecommentp = do
        satisfy isLineCommentStart
        void $ takeWhileP Nothing (/= '\n')
        optional newline
        pure ()
  
  {-# INLINABLE emptyorcommentlinep #-}
  
  -- | A newer comment line parser.
  -- Parses a line which is empty, all blanks, or whose first non-blank character is one of those provided.
  -- A final newline is optional.
  emptyorcommentlinep2 :: [Char] -> TextParser m ()
  emptyorcommentlinep2 cs =
    label ("empty line or comment line beginning with "++cs) $ do
      dp "emptyorcommentlinep2"
      skipNonNewlineSpaces
      void newline <|> void commentp
      where
        commentp = do
          choice (map (some.char) cs)
          takeWhileP Nothing (/='\n') <* optional newline
  
  -- | Is this a character that, as the first non-whitespace on a line,
  -- starts a comment line ?
  isLineCommentStart :: Char -> Bool
  isLineCommentStart '#' = True
  isLineCommentStart '*' = True
  isLineCommentStart ';' = True
  isLineCommentStart _   = False
  
  -- | Is this a character that, appearing anywhere within a line,
  -- starts a comment ?
  isSameLineCommentStart :: Char -> Bool
  isSameLineCommentStart ';' = True
  isSameLineCommentStart _   = False
  
  -- | Parse a comment following a journal item, possibly continued on multiple lines,
  -- and return the comment text.
  --
  -- >>> rtp followingcommentp ""   -- no comment
  -- Right ""
  -- >>> rtp followingcommentp ";"    -- just a (empty) same-line comment. newline is added
  -- Right "\n"
  -- >>> rtp followingcommentp ";  \n"
  -- Right "\n"
  -- >>> rtp followingcommentp ";\n ;\n"  -- a same-line and a next-line comment
  -- Right "\n\n"
  -- >>> rtp followingcommentp "\n ;\n"  -- just a next-line comment. Insert an empty same-line comment so the next-line comment doesn't become a same-line comment.
  -- Right "\n\n"
  --
  followingcommentp :: TextParser m Text
  followingcommentp = fst <$> followingcommentpWith (void $ takeWhileP Nothing (/= '\n'))
  
  {-# INLINABLE followingcommentp #-}
  
  -- | Parse a following comment, possibly continued on multiple lines,
  -- using the provided line parser to parse each line.
  -- This returns the comment text, and the combined results from the line parser.
  --
  -- Following comments are a 1-or-more-lines comment,
  -- beginning with a semicolon possibly preceded by whitespace on the current line,
  -- or with an indented semicolon on the next line.
  -- Additional lines also must begin with an indented semicolon.
  --
  -- Like Ledger, we sometimes allow data to be embedded in comments.
  -- account directive comments and transaction comments can contain tags,
  -- and posting comments can contain tags or bracketed posting dates.
  -- This helper lets us handle these variations. 
  -- The line parser should consume all input up until the next newline.
  -- See followingcommentp for some tests.
  --
  followingcommentpWith :: (Monoid a, Show a) => TextParser m a -> TextParser m (Text, a)
  followingcommentpWith contentp = do
    skipNonNewlineSpaces
    -- there can be 0 or 1 sameLine
    sameLine <- try headerp *> ((:[]) <$> match' contentp) <|> pure []
    _ <- eolof
    -- there can be 0 or more nextLines
    nextLines <- many $
      try (skipNonNewlineSpaces1 *> headerp) *> match' contentp <* eolof
    let
      -- if there's just a next-line comment, insert an empty same-line comment
      -- so the next-line comment doesn't get rendered as a same-line comment.
      sameLine' | null sameLine && not (null nextLines) = [("",mempty)]
                | otherwise = sameLine
      (texts, contents) = unzip $ sameLine' ++ nextLines
      strippedCommentText = T.unlines $ map T.strip texts
      commentContent = mconcat contents
    pure (strippedCommentText, commentContent)
  
    where
      headerp = char ';' *> skipNonNewlineSpaces
  
  {-# INLINABLE followingcommentpWith #-}
  
  
  -- Parse the tags from a single comment line, eg for use with followingcommentpWith.
  -- XXX what part of a comment line ? leading whitespace / semicolon or not ?
  commentlinetagsp :: TextParser m [Tag]
  commentlinetagsp = do
    -- XXX sketchy
    tagName <- (last . T.split isSpace) <$> takeWhileP Nothing (\c -> c /= ':' && c /= '\n')
    atColon tagName <|> pure [] -- if not ':', then either '\n' or EOF
  
    where
      atColon :: Text -> TextParser m [Tag]
      atColon name = char ':' *> do
        if T.null name
          then commentlinetagsp
          else do
            skipNonNewlineSpaces
            val <- tagValue
            let tag = (name, val)
            (tag:) <$> commentlinetagsp
  
      tagValue :: TextParser m Text
      tagValue = do
        val <- T.strip <$> takeWhileP Nothing (\c -> c /= ',' && c /= '\n')
        _ <- optional $ char ','
        pure val
  
  {-# INLINABLE commentlinetagsp #-}
  
  
  -- | Parse a transaction comment and extract its tags.
  --
  -- The first line of a transaction may be followed a 1-or-more-lines comment,
  -- beginning with a semicolon possibly preceded by whitespace on the current line,
  -- or with an indented semicolon on the next line. Additional lines also must
  -- begin with an indented semicolon.
  -- See also followingcommentpWith.
  --
  -- 2000/1/1 ; a transaction comment starting on the same line ...
  --   ; extending to the next line
  --   account1  $1
  --   account2
  --
  -- Tags are name-value pairs.
  --
  -- >>> let getTags (_,tags) = tags
  -- >>> let parseTags = fmap getTags . rtp transactioncommentp
  --
  -- >>> parseTags "; name1: val1, name2:all this is value2"
  -- Right [("name1","val1"),("name2","all this is value2")]
  --
  -- A tag's name must be immediately followed by a colon, without
  -- separating whitespace. The corresponding value consists of all the text
  -- following the colon up until the next colon or newline, stripped of
  -- leading and trailing whitespace.
  --
  transactioncommentp :: TextParser m (Text, [Tag])
  transactioncommentp = followingcommentpWith commentlinetagsp
  {-# INLINABLE transactioncommentp #-}
  
  
  -- | Parse a posting comment and extract its tags and dates.
  --
  -- Postings may be followed by comments, which begin with semicolons and
  -- extend to the end of the line. Posting comments may span multiple
  -- lines, but comment lines below the posting must be preceded by
  -- leading whitespace.
  --
  -- 2000/1/1
  --   account1  $1 ; a posting comment starting on the same line ...
  --   ; extending to the next line
  --
  --   account2
  --   ; a posting comment beginning on the next line
  --
  -- Tags are name-value pairs.
  --
  -- >>> let getTags (_,tags,_,_) = tags
  -- >>> let parseTags = fmap getTags . rtp (postingcommentp Nothing)
  --
  -- >>> parseTags "; name1: val1, name2:all this is value2"
  -- Right [("name1","val1"),("name2","all this is value2")]
  --
  -- A tag's name must be immediately followed by a colon, without
  -- separating whitespace. The corresponding value consists of all the text
  -- following the colon up until the next colon or newline, stripped of
  -- leading and trailing whitespace.
  --
  -- Posting dates may be expressed with "date"/"date2" tags or with
  -- bracketed date syntax. Posting dates will inherit their year from the
  -- transaction date if the year is not specified. We throw parse errors on
  -- invalid dates.
  --
  -- >>> let getDates (_,_,d1,d2) = (d1, d2)
  -- >>> let parseDates = fmap getDates . rtp (postingcommentp (Just 2000))
  --
  -- >>> parseDates "; date: 1/2, date2: 1999/12/31"
  -- Right (Just 2000-01-02,Just 1999-12-31)
  -- >>> parseDates "; [1/2=1999/12/31]"
  -- Right (Just 2000-01-02,Just 1999-12-31)
  --
  -- Example: tags, date tags, and bracketed dates
  -- >>> rtp (postingcommentp (Just 2000)) "; a:b, date:3/4, [=5/6]"
  -- Right ("a:b, date:3/4, [=5/6]\n",[("a","b"),("date","3/4")],Just 2000-03-04,Just 2000-05-06)
  --
  -- Example: extraction of dates from date tags ignores trailing text
  -- >>> rtp (postingcommentp (Just 2000)) "; date:3/4=5/6"
  -- Right ("date:3/4=5/6\n",[("date","3/4=5/6")],Just 2000-03-04,Nothing)
  --
  postingcommentp
    :: Maybe Year -> TextParser m (Text, [Tag], Maybe Day, Maybe Day)
  postingcommentp mYear = do
    (commentText, (tags, dateTags)) <-
      followingcommentpWith (commenttagsanddatesp mYear)
    let mdate  = snd <$> find ((=="date") .fst) dateTags
        mdate2 = snd <$> find ((=="date2").fst) dateTags
    pure (commentText, tags, mdate, mdate2)
  {-# INLINABLE postingcommentp #-}
  
  
  commenttagsanddatesp
    :: Maybe Year -> TextParser m ([Tag], [DateTag])
  commenttagsanddatesp mYear = do
    (txt, dateTags) <- match $ readUpTo ':'
    -- next char is either ':' or '\n' (or EOF)
    let tagName = last (T.split isSpace txt)
    (fmap.second) (dateTags++) (atColon tagName) <|> pure ([], dateTags) -- if not ':', then either '\n' or EOF
  
    where
      readUpTo :: Char -> TextParser m [DateTag]
      readUpTo end = do
        void $ takeWhileP Nothing (\c -> c /= end && c /= '\n' && c /= '[')
        -- if not '[' then ':' or '\n' or EOF
        atBracket (readUpTo end) <|> pure []
  
      atBracket :: TextParser m [DateTag] -> TextParser m [DateTag]
      atBracket cont = do
        -- Uses the fact that bracketed date-tags cannot contain newlines
        dateTags <- option [] $ lookAhead (bracketeddatetagsp mYear)
        _ <- char '['
        dateTags' <- cont
        pure $ dateTags ++ dateTags'
  
      atColon :: Text -> TextParser m ([Tag], [DateTag])
      atColon name = char ':' *> do
        skipNonNewlineSpaces
        (tags, dateTags) <- case name of
          ""      -> pure ([], [])
          "date"  -> dateValue name
          "date2" -> dateValue name
          _       -> tagValue name
        _ <- optional $ char ','
        bimap (tags++) (dateTags++) <$> commenttagsanddatesp mYear
  
      dateValue :: Text -> TextParser m ([Tag], [DateTag])
      dateValue name = do
        (txt, (date, dateTags)) <- match' $ do
          date <- datep' mYear
          dateTags <- readUpTo ','
          pure (date, dateTags)
        let val = T.strip txt
        pure $ ( [(name, val)]
               , (name, date) : dateTags )
  
      tagValue :: Text -> TextParser m ([Tag], [DateTag])
      tagValue name = do
        (txt, dateTags) <- match' $ readUpTo ','
        let val = T.strip txt
        pure $ ( [(name, val)]
               , dateTags )
  
  {-# INLINABLE commenttagsanddatesp #-}
  
  -- | Parse Ledger-style bracketed posting dates ([DATE=DATE2]), as
  -- "date" and/or "date2" tags. Anything that looks like an attempt at
  -- this (a square-bracketed sequence of 0123456789/-.= containing at
  -- least one digit and one date separator) is also parsed, and will
  -- throw an appropriate error.
  --
  -- The dates are parsed in full here so that errors are reported in
  -- the right position. A missing year in DATE can be inferred if a
  -- default date is provided. A missing year in DATE2 will be inferred
  -- from DATE.
  --
  -- >>> either (Left . customErrorBundlePretty) Right $ rtp (bracketeddatetagsp Nothing) "[2016/1/2=3/4]"
  -- Right [("date",2016-01-02),("date2",2016-03-04)]
  --
  -- >>> either (Left . customErrorBundlePretty) Right $ rtp (bracketeddatetagsp Nothing) "[1]"
  -- Left ...not a bracketed date...
  --
  -- >>> either (Left . customErrorBundlePretty) Right $ rtp (bracketeddatetagsp Nothing) "[2016/1/32]"
  -- Left ...1:2:...This is not a valid date...
  --
  -- >>> either (Left . customErrorBundlePretty) Right $ rtp (bracketeddatetagsp Nothing) "[1/31]"
  -- Left ...1:2:...This partial date can not be parsed because the current year is unknown...
  --
  -- >>> either (Left . customErrorBundlePretty) Right $ rtp (bracketeddatetagsp Nothing) "[0123456789/-.=/-.=]"
  -- Left ...1:13:...expecting month or day...
  --
  bracketeddatetagsp
    :: Maybe Year -> TextParser m [(TagName, Day)]
  bracketeddatetagsp mYear1 = do
    -- dbgparse 0 "bracketeddatetagsp"
    try $ do
      s <- lookAhead
         $ between (char '[') (char ']')
         $ takeWhile1P Nothing isBracketedDateChar
      unless (T.any isDigit s && T.any isDateSepChar s) $
        Fail.fail "not a bracketed date"
    -- Looks sufficiently like a bracketed date to commit to parsing a date
  
    between (char '[') (char ']') $ do
      md1 <- optional $ datep' mYear1
  
      let mYear2 = fmap readYear md1 <|> mYear1
      md2 <- optional $ char '=' *> datep' mYear2
  
      pure $ catMaybes [("date",) <$> md1, ("date2",) <$> md2]
  
    where
      readYear = first3 . toGregorian
      isBracketedDateChar c = isDigit c || isDateSepChar c || c == '='
  
  {-# INLINABLE bracketeddatetagsp #-}
  
  -- | Get the account name aliases from options, if any.
  aliasesFromOpts :: InputOpts -> [AccountAlias]
  aliasesFromOpts = map (\a -> fromparse $ runParser accountaliasp ("--alias "++quoteIfNeeded a) $ T.pack a)
                    . aliases_
  
  accountaliasp :: TextParser m AccountAlias
  accountaliasp = regexaliasp <|> basicaliasp
  
  basicaliasp :: TextParser m AccountAlias
  basicaliasp = do
    -- dbgparse 0 "basicaliasp"
    old <- rstrip <$> (some $ noneOf ("=" :: [Char]))
    char '='
    skipNonNewlineSpaces
    new <- rstrip <$> anySingle `manyTill` eolof  -- eol in journal, eof in command lines, normally
    return $ BasicAlias (T.pack old) (T.pack new)
  
  regexaliasp :: TextParser m AccountAlias
  regexaliasp = do
    -- dbgparse 0 "regexaliasp"
    (off1, off2, re) <- between (char '/') (char '/') $ do
      off1 <- getOffset
      re <- fmap T.concat . some $
               (T.singleton <$> noneOf ("/\\\n\r" :: [Char]))               -- paranoid: don't try to read past line end
               <|> string "\\/"                                             -- allow escaping forward slashes
               <|> (liftM2 T.cons (char '\\') (T.singleton <$> anySingle))  -- Otherwise leave backslashes in
      off2 <- getOffset
      return (off1, off2, re)
    skipNonNewlineSpaces
    char '='
    skipNonNewlineSpaces
    repl <- anySingle `manyTill` eolof
    case toRegexCI re of
      Right r -> return $! RegexAlias r repl
      Left e  -> customFailure $! parseErrorAtRegion off1 off2 e
  
  --- ** tests
  
  tests_Common = testGroup "Common" [
  
     testGroup "amountp" [
      testCase "basic"                  $ assertParseEq amountp "$47.18"     (usd 47.18)
     ,testCase "ends with decimal mark" $ assertParseEq amountp "$1."        (usd 1  `withPrecision` Precision 0)
     ,testCase "unit price"             $ assertParseEq amountp "$10 @ €0.5"
        -- not precise enough:
        -- (usd 10 `withPrecision` 0 `at` (eur 0.5 `withPrecision` 1)) -- `withStyle` asdecimalmark=Just '.'
        nullamt{
           acommodity="$"
          ,aquantity=10 -- need to test internal precision with roundTo ? I think not
          ,astyle=amountstyle{asprecision=Precision 0, asdecimalmark=Nothing}
          ,acost=Just $ UnitCost $
            nullamt{
               acommodity="€"
              ,aquantity=0.5
              ,astyle=amountstyle{asprecision=Precision 1, asdecimalmark=Just '.'}
              }
          }
     ,testCase "total price"            $ assertParseEq amountp "$10 @@ €5"
        nullamt{
           acommodity="$"
          ,aquantity=10
          ,astyle=amountstyle{asprecision=Precision 0, asdecimalmark=Nothing}
          ,acost=Just $ TotalCost $
            nullamt{
               acommodity="€"
              ,aquantity=5
              ,astyle=amountstyle{asprecision=Precision 0, asdecimalmark=Nothing}
              }
          }
     ,testCase "unit price, parenthesised" $ assertParse amountp "$10 (@) €0.5"
     ,testCase "total price, parenthesised" $ assertParse amountp "$10 (@@) €0.5"
     ]
  
    ,let p = lift (numberp Nothing) :: JournalParser IO (Quantity, Word8, Maybe Char, Maybe DigitGroupStyle) in
     testCase "numberp" $ do
       assertParseEq p "0"          (0, 0, Nothing, Nothing)
       assertParseEq p "1"          (1, 0, Nothing, Nothing)
       assertParseEq p "1.1"        (1.1, 1, Just '.', Nothing)
       assertParseEq p "1,000.1"    (1000.1, 1, Just '.', Just $ DigitGroups ',' [3])
       assertParseEq p "1.00.000,1" (100000.1, 1, Just ',', Just $ DigitGroups '.' [3,2])
       assertParseEq p "1,000,000"  (1000000, 0, Nothing, Just $ DigitGroups ',' [3,3])  -- could be simplified to [3]
       assertParseEq p "1."         (1, 0, Just '.', Nothing)
       assertParseEq p "1,"         (1, 0, Just ',', Nothing)
       assertParseEq p ".1"         (0.1, 1, Just '.', Nothing)
       assertParseEq p ",1"         (0.1, 1, Just ',', Nothing)
       assertParseError p "" ""
       assertParseError p "1,000.000,1" ""
       assertParseError p "1.000,000.1" ""
       assertParseError p "1,000.000.1" ""
       assertParseError p "1,,1" ""
       assertParseError p "1..1" ""
       assertParseError p ".1," ""
       assertParseError p ",1." ""
       assertParseEq    p "1.555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555" (1.555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555, 255, Just '.', Nothing)
       assertParseError p "1.5555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555" ""
  
    ,testGroup "spaceandamountormissingp" [
       testCase "space and amount" $ assertParseEq spaceandamountormissingp " $47.18" (mixedAmount $ usd 47.18)
      ,testCase "empty string" $ assertParseEq spaceandamountormissingp "" missingmixedamt
      -- ,testCase "just space" $ assertParseEq spaceandamountormissingp " " missingmixedamt  -- XXX should it ?
      -- ,testCase "just amount" $ assertParseError spaceandamountormissingp "$47.18" ""  -- succeeds, consuming nothing
      ]
  
    ]
  
  
  