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lib: clarify transaction balancing & balance assertion checking

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This commit is contained in:
Simon Michael 2019-02-15 10:34:40 -08:00
parent cf52eb1e42
commit 3b47b58aec
7 changed files with 371 additions and 324 deletions
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434
hledger-lib/Hledger/Data/Journal.hs
View File

@ -76,14 +76,13 @@ module Hledger.Data.Journal (
)
where
import Control.Applicative (Const(..))
import Control.Arrow
import Control.Monad
import Control.Monad.Except
import qualified Control.Monad.Reader as R
import Control.Monad.Reader as R
import Control.Monad.ST
import Data.Array.ST
import Data.Functor.Identity (Identity(..))
import qualified Data.HashTable.ST.Cuckoo as HT
import qualified Data.HashTable.ST.Cuckoo as H
import Data.List
import Data.List.Extra (groupSort)
import Data.Maybe
@ -563,51 +562,223 @@ journalUntieTransactions t@Transaction{tpostings=ps} = t{tpostings=map (\p -> p{
journalModifyTransactions :: Journal -> Journal
journalModifyTransactions j = j{ jtxns = modifyTransactions (jtxnmodifiers j) (jtxns j) }
-- | Check any balance assertions in the journal and return an error
-- message if any of them fail.
journalCheckBalanceAssertions :: Journal -> Either String Journal
journalCheckBalanceAssertions j =
runST $ journalBalanceTransactionsST
True
j
(return ())
(\_ _ -> return ())
(const $ return j)
-- | Check any balance assertions in the journal and return an error message
-- if any of them fail (or if the transaction balancing they require fails).
journalCheckBalanceAssertions :: Journal -> Maybe String
journalCheckBalanceAssertions = either Just (const Nothing) . journalBalanceTransactions True
-- | Check a posting's balance assertion and return an error if it
-- fails.
-- | Infer any missing amounts (to satisfy balance assignments and
-- to balance transactions) and check that all transactions balance
-- and (optional) all balance assertions pass. Or return an error message
-- (just the first error encountered).
--
-- Assumes journalInferCommodityStyles has been called, since those affect transaction balancing.
--
-- This does multiple things because amount inferring, balance assignments,
-- balance assertions and posting dates are interdependent.
--
-- Overview, 20190216:
-- @
-- ****** parseAndFinaliseJournal['] [[Cli/Utils.hs]], journalAddForecast [[Common.hs]], budgetJournal [[BudgetReport.hs]], tests [[BalanceReport.hs]]
-- ******* journalBalanceTransactions
-- ******** runST
-- ********* runExceptT
-- ********** runReaderT
-- *********** balanceNoAssignmentTransactionB
-- ************ balanceTransactionB [[Transaction.hs]]
-- ************* balanceTransactionHelper
-- ************** inferBalancingAmount
-- *********** balanceAssignmentTransactionAndOrCheckAssertionsB
-- ************ addAmountAndCheckBalanceAssertionB
-- ************* addToBalanceB
-- ************ inferFromAssignmentB
-- ************ balanceTransactionB [[Transaction.hs]]
-- ************* balanceTransactionHelper
-- ************ addToBalanceB
-- ****** uiCheckBalanceAssertions d ui@UIState{aopts=UIOpts{cliopts_=copts}, ajournal=j} [[ErrorScreen.hs]]
-- ******* journalCheckBalanceAssertions
-- ******** journalBalanceTransactions
-- ****** transactionWizard, postingsBalanced [[Add.hs]], tests [[Transaction.hs]]
-- ******* balanceTransaction
-- @
journalBalanceTransactions :: Bool -> Journal -> Either String Journal
journalBalanceTransactions assrt j' =
let
-- ensure transactions are numbered, so we can store them by number
j@Journal{jtxns=ts} = journalNumberTransactions j'
styles = journalCommodityStyles j
-- balance assignments will not be allowed on these
txnmodifieraccts = S.fromList $ map paccount $ concatMap tmpostingrules $ jtxnmodifiers j
in
runST $ do
bals <- H.newSized (length $ journalAccountNamesUsed j)
txns <- newListArray (1, genericLength ts) ts
runExceptT $ do
flip runReaderT (BalancingState styles txnmodifieraccts assrt bals txns) $ do
-- Fill in missing posting amounts, check transactions are balanced,
-- and check balance assertions. This is done in two passes:
-- 1. Balance the transactions which don't have balance assignments,
-- and collect their postings, plus the still-unbalanced transactions, in date order.
sortedpsandts <- sortOn (either postingDate tdate) . concat <$>
mapM' balanceNoAssignmentTransactionB (jtxns j)
-- 2. Step through these, keeping running account balances,
-- performing balance assignments in and balancing the remaining transactions,
-- and checking balance assertions. This last could be a separate pass
-- but perhaps it's more efficient to do all at once.
void $ mapM' balanceAssignmentTransactionAndOrCheckAssertionsB sortedpsandts
ts' <- lift $ getElems txns
return j{jtxns=ts'}
-- | If this transaction has no balance assignments, balance and store it
-- and return its postings. If it can't be balanced, an error will be thrown.
--
-- It it has balance assignments, return it unchanged. If any posting has both
-- a balance assignment and a custom date, an error will be thrown.
--
balanceNoAssignmentTransactionB :: Transaction -> Balancing s [Either Posting Transaction]
balanceNoAssignmentTransactionB t
| null (assignmentPostings t) = do
styles <- R.reader bsStyles
t' <- lift $ ExceptT $ return $ balanceTransaction (Just styles) t
storeTransactionB t'
return [Left $ removePrices p | p <- tpostings t']
| otherwise = do
when (any (isJust . pdate) $ tpostings t) $ -- XXX check more carefully that date and assignment are on same posting ?
throwError $
unlines $
[ "postings may not have both a custom date and a balance assignment."
, "Write the posting amount explicitly, or remove the posting date:\n"
, showTransaction t
]
return [Right $ t {tpostings = removePrices <$> tpostings t}]
-- | This function is called in turn on each item in a date-ordered sequence
-- of postings (from already-balanced transactions) or transactions
-- (not yet balanced, because containing balance assignments).
-- It applies balance assignments and balances the unbalanced transactions,
-- and checks any balance assertion(s).
--
-- For a posting: update the account's running balance, and
-- check the balance assertion if any.
--
-- For a transaction: for each posting,
--
-- - if it has a missing amount and a balance assignment, infer the amount
--
-- - update the account's running balance
--
-- - check the balance assertion if any
--
-- Then balance the transaction, so that any remaining missing amount is inferred.
-- And if that happened, also update *that* account's running balance. XXX and check the assertion ?
-- And store the transaction.
--
-- Will throw an error if a transaction can't be balanced,
-- or if an illegal balance assignment is found (cf checkIllegalBalanceAssignment).
--
balanceAssignmentTransactionAndOrCheckAssertionsB :: Either Posting Transaction -> Balancing s ()
balanceAssignmentTransactionAndOrCheckAssertionsB (Left p) = do
checkIllegalBalanceAssignmentB p
void $ addAmountAndCheckBalanceAssertionB return p
balanceAssignmentTransactionAndOrCheckAssertionsB (Right t@Transaction{tpostings=ps}) = do
mapM_ checkIllegalBalanceAssignmentB ps
ps' <- forM ps $ addAmountAndCheckBalanceAssertionB inferFromAssignmentB
styles <- R.reader bsStyles
storeTransactionB =<<
balanceTransactionB (fmap void . addToBalanceB) (Just styles) t{tpostings=ps'}
-- | Throw an error if this posting is trying to do a balance assignment and
-- the account does not allow balance assignments (because it is referenced
-- by a transaction modifier).
checkIllegalBalanceAssignmentB :: Posting -> Balancing s ()
checkIllegalBalanceAssignmentB p = do
unassignable <- R.asks bsUnassignable
when (isAssignment p && paccount p `S.member` unassignable) $
throwError $
unlines $
[ "cannot assign amount to account "
, ""
, " " ++ T.unpack (paccount p)
, ""
, "because it is also included in transaction modifiers."
]
-- | If this posting has a missing amount and a balance assignment, use
-- the running account balance to infer the amount required to satisfy
-- the assignment.
inferFromAssignmentB :: Posting -> Balancing s Posting
inferFromAssignmentB p@Posting{paccount=acc} =
case pbalanceassertion p of
Nothing -> return p
Just ba | batotal ba -> do
diff <- setAccountRunningBalance acc $ Mixed [baamount ba]
return $ setPostingAmount diff p
Just ba -> do
oldbal <- fromMaybe 0 <$> liftB (\bs -> H.lookup (bsBalances bs) acc)
let amt = baamount ba
newbal = filterMixedAmount ((/=acommodity amt).acommodity) oldbal + Mixed [amt]
diff <- setAccountRunningBalance acc newbal
return $ setPostingAmount diff p
where
setPostingAmount a p = p{pamount=a, porigin=Just $ originalPosting p}
-- | Set the account's running balance, and return the difference from the old.
setAccountRunningBalance :: AccountName -> MixedAmount -> Balancing s MixedAmount
setAccountRunningBalance acc amt = liftB $ \BalancingState{bsBalances=bals} -> do
old <- fromMaybe 0 <$> H.lookup bals acc
H.insert bals acc amt
return $ amt - old
-- | Adds a posting's amount to the posting's account's running balance, and
-- checks the posting's balance assertion if any. Or if the posting has no
-- amount, runs the supplied fallback action.
addAmountAndCheckBalanceAssertionB ::
(Posting -> Balancing s Posting) -- ^ fallback action
-> Posting
-> Balancing s Posting
addAmountAndCheckBalanceAssertionB _ p | hasAmount p = do
newAmt <- addToBalanceB (paccount p) (pamount p)
assrt <- R.reader bsAssrt
lift $ when assrt $ ExceptT $ return $ checkBalanceAssertion p newAmt
return p
addAmountAndCheckBalanceAssertionB fallback p = fallback p
-- | Check a posting's balance assertion against the given actual balance, and
-- return an error if the assertion is not satisfied.
-- If the assertion is partial, unasserted commodities in the actual balance
-- are ignored; if it is total, they will cause the assertion to fail.
checkBalanceAssertion :: Posting -> MixedAmount -> Either String ()
checkBalanceAssertion p@Posting{pbalanceassertion=Just (BalanceAssertion{baamount,baexact})} actualbal =
checkBalanceAssertion p@Posting{pbalanceassertion=Just (BalanceAssertion{baamount,batotal})} actualbal =
foldl' f (Right ()) assertedamts
where
f (Right _) assertedamt = checkBalanceAssertionCommodity p assertedamt actualbal
f (Right _) assertedamt = checkBalanceAssertionOneCommodity p assertedamt actualbal
f err _ = err
assertedamts = baamount : otheramts
where
assertedcomm = acommodity baamount
otheramts | baexact = map (\a -> a{ aquantity = 0 }) $ amounts $ filterMixedAmount (\a -> acommodity a /= assertedcomm) actualbal
otheramts | batotal = map (\a -> a{ aquantity = 0 }) $ amounts $ filterMixedAmount (\a -> acommodity a /= assertedcomm) actualbal
| otherwise = []
checkBalanceAssertion _ _ = Right ()
-- | Are the asserted balance and the actual balance
-- exactly equal (disregarding display precision) ?
-- The posting is used for creating an error message.
checkBalanceAssertionCommodity :: Posting -> Amount -> MixedAmount -> Either String ()
checkBalanceAssertionCommodity p assertedamt actualbal
-- | Does this (single commodity) expected balance match the amount of that
-- commodity in the given (multicommodity) actual balance ? If not, returns a
-- balance assertion failure message based on the provided posting. To match,
-- the amounts must be exactly equal (display precision is ignored here).
checkBalanceAssertionOneCommodity :: Posting -> Amount -> MixedAmount -> Either String ()
checkBalanceAssertionOneCommodity p assertedamt actualbal
| pass = Right ()
| otherwise = Left err
| otherwise = Left errmsg
where
assertedcomm = acommodity assertedamt
actualbalincommodity = fromMaybe nullamt $ find ((== assertedcomm) . acommodity) (amounts actualbal)
pass =
aquantity
-- traceWith (("asserted:"++).showAmountDebug)
assertedamt ==
-- traceWith (("asserted:"++).showAmountDebug)
assertedamt ==
aquantity
-- traceWith (("actual:"++).showAmountDebug)
actualbalincommodity
diff = aquantity assertedamt - aquantity actualbalincommodity
err = printf (unlines
-- traceWith (("actual:"++).showAmountDebug)
actualbalincommodity
errmsg = printf (unlines
[ "balance assertion: %s",
"\nassertion details:",
"date: %s",
@ -635,208 +806,7 @@ checkBalanceAssertionCommodity p assertedamt actualbal
-- (showAmount actualbalincommodity)
(show $ aquantity assertedamt)
-- (showAmount assertedamt)
(show diff)
-- | Fill in any missing amounts and check that all journal transactions
-- balance and all balance assertions pass, or return an error message.
-- This is done after parsing all amounts and applying canonical
-- commodity styles, since balancing depends on display precision.
-- Reports only the first error encountered.
journalBalanceTransactions :: Bool -> Journal -> Either String Journal
journalBalanceTransactions assrt j =
runST $ journalBalanceTransactionsST
assrt -- check balance assertions also ?
(journalNumberTransactions j) -- journal to process
(newArray_ (1, genericLength $ jtxns j) :: forall s. ST s (STArray s Integer Transaction)) -- initialise state
(\arr tx -> writeArray arr (tindex tx) tx) -- update state
(fmap (\txns -> j{ jtxns = txns}) . getElems) -- summarise state
-- | Helper used by 'journalBalanceTransactions' and 'journalCheckBalanceAssertions'.
-- Balances transactions, applies balance assignments, and checks balance assertions
-- at the same time.
journalBalanceTransactionsST ::
Bool
-> Journal
-> ST s txns -- ^ initialise state
-> (txns -> Transaction -> ST s ()) -- ^ update state
-> (txns -> ST s a) -- ^ summarise state
-> ST s (Either String a)
journalBalanceTransactionsST assrt j createStore storeIn extract =
runExceptT $ do
bals <- lift $ HT.newSized size
txStore <- lift $ createStore
let env = Env bals
(storeIn txStore)
assrt
(Just $ journalCommodityStyles j)
(getModifierAccountNames j)
flip R.runReaderT env $ do
dated <- fmap snd . sortOn fst . concat
<$> mapM' discriminateByDate (jtxns j)
mapM' checkInferAndRegisterAmounts dated
lift $ extract txStore
where
size = genericLength $ journalPostings j
-- | Collect account names in account modifiers into a set
getModifierAccountNames :: Journal -> S.Set AccountName
getModifierAccountNames j = S.fromList $
map paccount $
concatMap tmpostingrules $
jtxnmodifiers j
-- | Monad transformer stack with a reference to a mutable hashtable
-- of current account balances and a mutable array of finished
-- transactions in original parsing order.
type CurrentBalancesModifier s = R.ReaderT (Env s) (ExceptT String (ST s))
-- | Environment for 'CurrentBalancesModifier'
data Env s = Env { eBalances :: HT.HashTable s AccountName MixedAmount
, eStoreTx :: Transaction -> ST s ()
, eAssrt :: Bool
, eStyles :: Maybe (M.Map CommoditySymbol AmountStyle)
, eUnassignable :: S.Set AccountName
}
-- | This converts a transaction into a list of transactions or
-- postings whose dates have to be considered when checking
-- balance assertions and handled by 'checkInferAndRegisterAmounts'.
--
-- Transaction without balance assignments can be balanced and stored
-- immediately and their (possibly) dated postings are returned.
--
-- Transaction with balance assignments are only supported if no
-- posting has a 'pdate' value. Supported transactions will be
-- returned unchanged and balanced and stored later in 'checkInferAndRegisterAmounts'.
discriminateByDate :: Transaction
-> CurrentBalancesModifier s [(Day, Either Posting Transaction)]
discriminateByDate tx
| null (assignmentPostings tx) = do
styles <- R.reader $ eStyles
balanced <- lift $ ExceptT $ return $ balanceTransaction styles tx
storeTransaction balanced
return $ fmap (postingDate &&& (Left . removePrices)) $ tpostings $ balanced
| otherwise = do
when (any (isJust . pdate) $ tpostings tx) $
throwError $
unlines $
[ "postings may not have both a custom date and a balance assignment."
, "Write the posting amount explicitly, or remove the posting date:\n"
, showTransaction tx
]
return [(tdate tx, Right $ tx {tpostings = removePrices <$> tpostings tx})]
-- | Throw an error if a posting is in the unassignable set.
checkUnassignablePosting :: Posting -> CurrentBalancesModifier s ()
checkUnassignablePosting p = do
unassignable <- R.asks eUnassignable
when (isAssignment p && paccount p `S.member` unassignable) $
throwError $
unlines $
[ "cannot assign amount to account "
, ""
, " " ++ T.unpack (paccount p)
, ""
, "because it is also included in transaction modifiers."
]
-- | This function takes an object describing changes to
-- account balances on a single day - either a single posting
-- (from an already balanced transaction without assignments)
-- or a whole transaction with assignments (which is required to
-- have no posting with pdate set).
--
-- For a single posting, there is not much to do. Only add its amount
-- to its account and check the assertion, if there is one. This
-- functionality is provided by 'addAmountAndCheckBalance'.
--
-- For a whole transaction, it loops over all postings, and performs
-- 'addAmountAndCheckBalance', if there is an amount. If there is no
-- amount, the amount is inferred by the assertion or left empty if
-- there is no assertion. Then, the transaction is balanced, the
-- inferred amount added to the balance (all in 'balanceTransactionUpdate')
-- and the resulting transaction with no missing amounts is stored
-- in the array, for later retrieval.
--
-- Again in short:
--
-- 'Left Posting': Check the balance assertion and update the
-- account balance. If the amount is empty do nothing. this can be
-- the case e.g. for virtual postings
--
-- 'Right Transaction': Loop over all postings, infer their amounts
-- and then balance and store the transaction.
checkInferAndRegisterAmounts :: Either Posting Transaction
-> CurrentBalancesModifier s ()
checkInferAndRegisterAmounts (Left p) = do
checkUnassignablePosting p
void $ addAmountAndCheckBalance return p
checkInferAndRegisterAmounts (Right oldTx) = do
let ps = tpostings oldTx
mapM_ checkUnassignablePosting ps
styles <- R.reader $ eStyles
newPostings <- forM ps $ addAmountAndCheckBalance inferFromAssignment
storeTransaction =<< balanceTransactionUpdate
(fmap void . addToBalance) styles oldTx { tpostings = newPostings }
where
inferFromAssignment :: Posting -> CurrentBalancesModifier s Posting
inferFromAssignment p = do
let acc = paccount p
case pbalanceassertion p of
Just ba | baexact ba -> do
diff <- setMixedBalance acc $ Mixed [baamount ba]
fullPosting diff p
Just ba -> do
old <- liftModifier $ \Env{ eBalances = bals } -> HT.lookup bals acc
let amt = baamount ba
assertedcomm = acommodity amt
diff <- setMixedBalance acc $
Mixed [amt] + filterMixedAmount (\a -> acommodity a /= assertedcomm) (fromMaybe nullmixedamt old)
fullPosting diff p
Nothing -> return p
fullPosting amt p = return p
{ pamount = amt
, porigin = Just $ originalPosting p
}
-- | Adds a posting's amount to the posting's account balance and
-- checks a possible balance assertion. Or if there is no amount,
-- runs the supplied fallback action.
addAmountAndCheckBalance ::
(Posting -> CurrentBalancesModifier s Posting) -- ^ action if posting has no amount
-> Posting
-> CurrentBalancesModifier s Posting
addAmountAndCheckBalance _ p | hasAmount p = do
newAmt <- addToBalance (paccount p) $ pamount p
assrt <- R.reader eAssrt
lift $ when assrt $ ExceptT $ return $ checkBalanceAssertion p newAmt
return p
addAmountAndCheckBalance fallback p = fallback p
-- | Sets all commodities comprising an account's balance to the given
-- amounts and returns the difference from the previous balance.
setMixedBalance :: AccountName -> MixedAmount -> CurrentBalancesModifier s MixedAmount
setMixedBalance acc amt = liftModifier $ \Env{ eBalances = bals } -> do
old <- HT.lookup bals acc
HT.insert bals acc amt
return $ maybe amt (amt -) old
-- | Adds an amount to an account's balance and returns the resulting balance.
addToBalance :: AccountName -> MixedAmount -> CurrentBalancesModifier s MixedAmount
addToBalance acc amt = liftModifier $ \Env{ eBalances = bals } -> do
new <- maybe amt (+ amt) <$> HT.lookup bals acc
HT.insert bals acc new
return new
-- | Stores a transaction in the transaction array in original parsing order.
storeTransaction :: Transaction -> CurrentBalancesModifier s ()
storeTransaction tx = liftModifier $ ($tx) . eStoreTx
-- | Helper function.
liftModifier :: (Env s -> ST s a) -> CurrentBalancesModifier s a
liftModifier f = R.ask >>= lift . lift . f
(show $ aquantity assertedamt - aquantity actualbalincommodity)
-- | Choose and apply a consistent display format to the posting
-- amounts in each commodity. Each commodity's format is specified by

2
hledger-lib/Hledger/Data/Posting.hs
View File

@ -104,7 +104,7 @@ nullsourcepos = JournalSourcePos "" (1,1)
nullassertion, assertion :: BalanceAssertion
nullassertion = BalanceAssertion
{baamount=nullamt
,baexact=False
,batotal=False
,baposition=nullsourcepos
}
assertion = nullassertion

191
hledger-lib/Hledger/Data/Transaction.hs
View File

@ -1,4 +1,3 @@
{-# LANGUAGE FlexibleContexts #-}
{-|
A 'Transaction' represents a movement of some commodity(ies) between two
@ -8,7 +7,11 @@ tags.
-}
{-# LANGUAGE OverloadedStrings, LambdaCase #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE Rank2Types #-}
{-# LANGUAGE RecordWildCards #-}
module Hledger.Data.Transaction (
-- * Transaction
@ -24,13 +27,18 @@ module Hledger.Data.Transaction (
balancedVirtualPostings,
transactionsPostings,
isTransactionBalanced,
balanceTransaction,
Balancing,
BalancingState(..),
addToBalanceB,
storeTransactionB,
liftB,
balanceTransactionB,
-- nonzerobalanceerror,
-- * date operations
transactionDate2,
-- * arithmetic
transactionPostingBalances,
balanceTransaction,
balanceTransactionUpdate,
-- * rendering
showTransaction,
showTransactionUnelided,
@ -47,7 +55,12 @@ module Hledger.Data.Transaction (
where
import Data.List
import Control.Monad.Except
import Control.Monad.Identity
import Control.Monad.Reader (ReaderT, ask)
import Control.Monad.ST
import Data.Array.ST
import qualified Data.HashTable.ST.Cuckoo as HT
import qualified Data.Map as M
import qualified Data.Set as S
import Data.Maybe
import Data.Text (Text)
import qualified Data.Text as T
@ -324,34 +337,78 @@ isTransactionBalanced styles t =
bvsum' = canonicalise $ costOfMixedAmount bvsum
canonicalise = maybe id canonicaliseMixedAmount styles
-- | Ensure this transaction is balanced, possibly inferring a missing
-- amount or conversion price(s), or return an error message.
-- Balancing is affected by commodity display precisions, so those can
-- (optionally) be provided.
--
-- this fails for example, if there are several missing amounts
-- (possibly with balance assignments)
balanceTransaction :: Maybe (Map.Map CommoditySymbol AmountStyle)
-> Transaction -> Either String Transaction
balanceTransaction stylemap = runIdentity . runExceptT
. balanceTransactionUpdate (\_ _ -> return ()) stylemap
-- | Monad used for statefully "balancing" a sequence of transactions.
type Balancing s = ReaderT (BalancingState s) (ExceptT String (ST s))
-- | The state used while balancing a sequence of transactions.
data BalancingState s = BalancingState {
-- read only
bsStyles :: M.Map CommoditySymbol AmountStyle -- ^ commodity display styles
,bsUnassignable :: S.Set AccountName -- ^ accounts in which balance assignments may not be used
,bsAssrt :: Bool -- ^ whether to check balance assertions
-- mutable
,bsBalances :: HT.HashTable s AccountName MixedAmount -- ^ running account balances, initially empty
,bsTransactions :: STArray s Integer Transaction -- ^ the transactions being balanced
}
-- | Lift a BalancingState mutator through the Except and Reader
-- layers into the Balancing monad.
liftB :: (BalancingState s -> ST s a) -> Balancing s a
liftB f = ask >>= lift . lift . f
-- | Add this amount to this account's running balance,
-- and return the new running balance.
addToBalanceB :: AccountName -> MixedAmount -> Balancing s MixedAmount
addToBalanceB acc amt = liftB $ \BalancingState{bsBalances=bals} -> do
b <- maybe amt (+amt) <$> HT.lookup bals acc
HT.insert bals acc b
return b
-- | Update (overwrite) this transaction with a new one.
storeTransactionB :: Transaction -> Balancing s ()
storeTransactionB t = liftB $ \bs ->
void $ writeArray (bsTransactions bs) (tindex t) t
-- | More general version of 'balanceTransaction' that takes an update
-- function
balanceTransactionUpdate :: MonadError String m
=> (AccountName -> MixedAmount -> m ())
-- ^ update function
-> Maybe (Map.Map CommoditySymbol AmountStyle)
-> Transaction -> m Transaction
balanceTransactionUpdate update mstyles t =
(finalize =<< inferBalancingAmount update (fromMaybe Map.empty mstyles) t)
`catchError` (throwError . annotateErrorWithTxn t)
-- | Balance this transaction, ensuring that its postings sum to 0,
-- by inferring a missing amount or conversion price(s) if needed.
-- Or if balancing is not possible, because of unbalanced amounts or
-- more than one missing amount, returns an error message.
-- Whether postings "sum to 0" depends on commodity display precisions,
-- so those can optionally be provided.
balanceTransaction ::
Maybe (Map.Map CommoditySymbol AmountStyle) -- ^ commodity display styles
-> Transaction
-> Either String Transaction
balanceTransaction mstyles = fmap fst . balanceTransactionHelper mstyles
-- | Like balanceTransaction, but when inferring amounts it will also
-- use the given state update function to update running account balances.
-- Used when balancing a sequence of transactions (see journalBalanceTransactions).
balanceTransactionB ::
(AccountName -> MixedAmount -> Balancing s ()) -- ^ function to update running balances
-> Maybe (Map.Map CommoditySymbol AmountStyle) -- ^ commodity display styles
-> Transaction
-> Balancing s Transaction
balanceTransactionB updatebalsfn mstyles t = do
case balanceTransactionHelper mstyles t of
Left err -> throwError err
Right (t', inferredacctsandamts) -> do
mapM_ (uncurry updatebalsfn) inferredacctsandamts
return t'
balanceTransactionHelper ::
Maybe (Map.Map CommoditySymbol AmountStyle) -- ^ commodity display styles
-> Transaction
-> Either String (Transaction, [(AccountName, MixedAmount)])
balanceTransactionHelper mstyles t = do
(t', inferredamtsandaccts) <-
inferBalancingAmount (fromMaybe Map.empty mstyles) $ inferBalancingPrices t
if isTransactionBalanced mstyles t'
then Right (txnTieKnot t', inferredamtsandaccts)
else Left $ annotateErrorWithTxn t' $ nonzerobalanceerror t'
where
finalize t' = let t'' = inferBalancingPrices t'
in if isTransactionBalanced mstyles t''
then return $ txnTieKnot t''
else throwError $ nonzerobalanceerror t''
nonzerobalanceerror :: Transaction -> String
nonzerobalanceerror t = printf "could not balance this transaction (%s%s%s)" rmsg sep bvmsg
where
@ -364,45 +421,52 @@ balanceTransactionUpdate update mstyles t =
++ showMixedAmount (costOfMixedAmount bvsum)
sep = if not (null rmsg) && not (null bvmsg) then "; " else "" :: String
annotateErrorWithTxn t e = intercalate "\n" [showGenericSourcePos $ tsourcepos t, e, showTransactionUnelided t]
annotateErrorWithTxn :: Transaction -> String -> String
annotateErrorWithTxn t s = intercalate "\n" [showGenericSourcePos $ tsourcepos t, s, showTransactionUnelided t]
-- | Infer up to one missing amount for this transactions's real postings, and
-- likewise for its balanced virtual postings, if needed; or return an error
-- message if we can't.
-- message if we can't. Returns the updated transaction and any inferred posting amounts,
-- with the corresponding accounts, in order).
--
-- We can infer a missing amount when there are multiple postings and exactly
-- one of them is amountless. If the amounts had price(s) the inferred amount
-- have the same price(s), and will be converted to the price commodity.
inferBalancingAmount :: MonadError String m =>
(AccountName -> MixedAmount -> m ()) -- ^ update function
-> Map.Map CommoditySymbol AmountStyle -- ^ standard amount styles
-> Transaction
-> m Transaction
inferBalancingAmount update styles t@Transaction{tpostings=ps}
inferBalancingAmount ::
Map.Map CommoditySymbol AmountStyle -- ^ commodity display styles
-> Transaction
-> Either String (Transaction, [(AccountName, MixedAmount)])
inferBalancingAmount styles t@Transaction{tpostings=ps}
| length amountlessrealps > 1
= throwError "could not balance this transaction - can't have more than one real posting with no amount (remember to put 2 or more spaces before amounts)"
= Left $ annotateErrorWithTxn t "could not balance this transaction - can't have more than one real posting with no amount (remember to put 2 or more spaces before amounts)"
| length amountlessbvps > 1
= throwError "could not balance this transaction - can't have more than one balanced virtual posting with no amount (remember to put 2 or more spaces before amounts)"
= Left $ annotateErrorWithTxn t "could not balance this transaction - can't have more than one balanced virtual posting with no amount (remember to put 2 or more spaces before amounts)"
| otherwise
= do postings <- mapM inferamount ps
return t{tpostings=postings}
= let psandinferredamts = map inferamount ps
inferredacctsandamts = [(paccount p, amt) | (p, Just amt) <- psandinferredamts]
in Right (t{tpostings=map fst psandinferredamts}, inferredacctsandamts)
where
(amountfulrealps, amountlessrealps) = partition hasAmount (realPostings t)
realsum = sumStrict $ map pamount amountfulrealps
(amountfulbvps, amountlessbvps) = partition hasAmount (balancedVirtualPostings t)
bvsum = sumStrict $ map pamount amountfulbvps
inferamount p@Posting{ptype=RegularPosting}
| not (hasAmount p) = updateAmount p realsum
inferamount p@Posting{ptype=BalancedVirtualPosting}
| not (hasAmount p) = updateAmount p bvsum
inferamount p = return p
updateAmount p amt =
update (paccount p) amt' >> return p { pamount=amt', porigin=Just $ originalPosting p }
where
-- Inferred amounts are converted to cost.
-- Also, ensure the new amount has the standard style for its commodity
-- (the main amount styling pass happened before this balancing pass).
amt' = styleMixedAmount styles $ normaliseMixedAmount $ costOfMixedAmount (-amt)
inferamount :: Posting -> (Posting, Maybe MixedAmount)
inferamount p =
let
minferredamt = case ptype p of
RegularPosting | not (hasAmount p) -> Just realsum
BalancedVirtualPosting | not (hasAmount p) -> Just bvsum
_ -> Nothing
in
case minferredamt of
Nothing -> (p, Nothing)
Just a -> (p{pamount=a', porigin=Just $ originalPosting p}, Just a')
where
-- Inferred amounts are converted to cost.
-- Also ensure the new amount has the standard style for its commodity
-- (since the main amount styling pass happened before this balancing pass);
a' = styleMixedAmount styles $ normaliseMixedAmount $ costOfMixedAmount (-a)
-- | Infer prices for this transaction's posting amounts, if needed to make
-- the postings balance, and if possible. This is done once for the real
@ -627,17 +691,14 @@ tests_Transaction =
in postingsAsLines False False t (tpostings t) `is`
[" a $-0.01", " b $0.005", " c $0.005"]
]
, do let inferTransaction :: Transaction -> Either String Transaction
inferTransaction = runIdentity . runExceptT . inferBalancingAmount (\_ _ -> return ()) Map.empty
tests
"inferBalancingAmount"
[ inferTransaction nulltransaction `is` Right nulltransaction
, inferTransaction nulltransaction {tpostings = ["a" `post` usd (-5), "b" `post` missingamt]} `is`
Right nulltransaction {tpostings = ["a" `post` usd (-5), "b" `post` usd 5]}
, inferTransaction
nulltransaction {tpostings = ["a" `post` usd (-5), "b" `post` (eur 3 @@ usd 4), "c" `post` missingamt]} `is`
Right nulltransaction {tpostings = ["a" `post` usd (-5), "b" `post` (eur 3 @@ usd 4), "c" `post` usd 1]}
]
, tests
"inferBalancingAmount"
[ (fst <$> inferBalancingAmount Map.empty nulltransaction) `is` Right nulltransaction
, (fst <$> inferBalancingAmount Map.empty nulltransaction{tpostings = ["a" `post` usd (-5), "b" `post` missingamt]}) `is`
Right nulltransaction{tpostings = ["a" `post` usd (-5), "b" `post` usd 5]}
, (fst <$> inferBalancingAmount Map.empty nulltransaction{tpostings = ["a" `post` usd (-5), "b" `post` (eur 3 @@ usd 4), "c" `post` missingamt]}) `is`
Right nulltransaction{tpostings = ["a" `post` usd (-5), "b" `post` (eur 3 @@ usd 4), "c" `post` usd 1]}
]
, tests
"showTransaction"
[ test "show a balanced transaction, eliding last amount" $

53
hledger-lib/Hledger/Data/Types.hs
View File

@ -238,32 +238,47 @@ instance Show Status where -- custom show.. bad idea.. don't do it..
show Pending = "!"
show Cleared = "*"
-- | The amount to compare an account's balance to, to verify that the history
-- leading to a given point is correct or to set the account to a known value.
-- | A balance assertion is a declaration about an account's expected balance
-- at a certain point (posting date and parse order). They provide additional
-- error checking and readability to a journal file.
--
-- Different kinds of balance assertion (from #290):
-- The 'BalanceAssertion' type is also used to represent balance assignments,
-- which instruct hledger what an account's balance should become at a certain
-- point.
--
-- * simple assertions: single-commodity, non-total, subaccount-exclusive
-- assertions, as in Ledger (syntax: `=`). See definitions below.
-- Different kinds of balance assertions are discussed eg on #290.
-- Variables include:
--
-- * subaccount-inclusive assertions: asserting the balance of an account
-- including all its subaccounts' balances. Not implemented, proposed by #290.
-- - which postings are to be summed (real/virtual; unmarked/pending/cleared; this account/this account including subs)
--
-- * multicommodity assertions: writing multiple amounts separated by + to
-- assert a multicommodity balance, in a single assertion. Not implemented,
-- proposed by #934. In current hledger you can assert a multicommodity
-- balance by using multiple postings/assertions. But in either case, the
-- balance might contain additional unasserted commodities. To disallow that
-- you need...
-- - which commodities within the balance are to be checked
--
-- * total assertions: asserting that the balance is as written, with no extra
-- commodities in the account. Added by #902, with syntax `==`. I sometimes
-- wish this was the default behaviour, of `=`.
-- - whether to do a partial or a total check (disallowing other commodities)
--
-- I suspect we want:
--
-- 1. partial, subaccount-exclusive, Ledger-compatible assertions. Because
-- they're what we've always had, and removing them would break some
-- journals unnecessarily. Implemented with = syntax.
--
-- 2. total assertions. Because otherwise assertions are a bit leaky.
-- Implemented with == syntax.
--
-- 3. subaccount-inclusive assertions. Because that's something folks need.
-- Not implemented.
--
-- 4. flexible assertions allowing custom criteria (perhaps arbitrary
-- queries). Because power users have diverse needs and want to try out
-- different schemes (assert cleared balances, assert balance from real or
-- virtual postings, etc.). Not implemented.
--
-- 5. multicommodity assertions, asserting the balance of multiple commodities
-- at once. Not implemented, requires #934.
--
data BalanceAssertion = BalanceAssertion {
baamount :: Amount, -- ^ the expected balance of a single commodity
baexact :: Bool, -- ^ whether the assertion is total, ie disallowing amounts in other commodities
baposition :: GenericSourcePos
baamount :: Amount, -- ^ the expected balance in a particular commodity
batotal :: Bool, -- ^ disallow additional non-asserted commodities ?
baposition :: GenericSourcePos -- ^ the assertion's file position, for error reporting
} deriving (Eq,Typeable,Data,Generic,Show)
instance NFData BalanceAssertion

6
hledger-lib/Hledger/Read/Common.hs
View File

@ -728,14 +728,14 @@ balanceassertionp :: JournalParser m BalanceAssertion
balanceassertionp = do
sourcepos <- genericSourcePos <$> lift getSourcePos
char '='
exact <- optional $ try $ char '='
istotal <- fmap isJust $ optional $ try $ char '='
lift (skipMany spacenonewline)
-- this amount can have a price; balance assertions ignore it,
-- but balance assignments will use it
a <- amountp <?> "amount (for a balance assertion or assignment)"
return BalanceAssertion
{ baamount = a
, baexact = isJust exact
{ baamount = a
, batotal = istotal
, baposition = sourcepos
}

4
hledger-ui/Hledger/UI/ErrorScreen.hs
View File

@ -176,8 +176,8 @@ uiCheckBalanceAssertions d ui@UIState{aopts=UIOpts{cliopts_=copts}, ajournal=j}
| ignore_assertions_ $ inputopts_ copts = ui
| otherwise =
case journalCheckBalanceAssertions j of
Right _ -> ui
Left err ->
Nothing -> ui
Just err ->
case ui of
UIState{aScreen=s@ErrorScreen{}} -> ui{aScreen=s{esError=err}}
_ -> screenEnter d errorScreen{esError=err} ui

5
tests/journal/parse-errors.test
View File

@ -63,10 +63,11 @@ $ hledger -f - print -x
c
$ hledger -f journal:- print
>2 /\<4\>/
>2 /could not balance this transaction - can't have more than one real posting with no amount/
>=1
# 7. Two (or more) virtual postings with implicit amount cannot be balanced.
# (And the error message contains line numbers).
<
2018/1/1
[a] 1
@ -74,5 +75,5 @@ $ hledger -f journal:- print
[c]
$ hledger -f journal:- print
>2 /\<4\>/
>2 /lines 1-4/
>=1