From dabb3ef82e1bd95744cfe8b1830e5a1038598759 Mon Sep 17 00:00:00 2001
From: Stephen Morgan <morgan.stephen99@gmail.com>
Date: Fri, 29 Jan 2021 23:34:18 +1100
Subject: [PATCH 1/2] lib,cli,ui,bin: Create a new API for MixedAmount
 arithmetic. This should supplant the old interface, which relied on the Num
 typeclass.

MixedAmount did not have a very good Num instance. The only functions
which were defined were fromInteger, (+), and negate. Furthermore, it
was not law-abiding, as 0 + a /= a in general. Replacements for used
functions are:
0 -> nullmixedamt / mempty
(+) -> maPlus / (<>)
(-) -> maMinus
negate -> maNegate
sum -> maSum
sumStrict -> maSum

Also creates some new constructors for MixedAmount:
mixedAmount :: Amount -> MixedAmount
maAddAmount :: MixedAmount -> Amount -> MixedAmount
maAddAmounts :: MixedAmount -> [Amount] -> MixedAmount

Add Semigroup and Monoid instances for MixedAmount.
Ideally we would remove the Num instance entirely.

The only change needed have nullmixedamt/mempty substitute for
0 without problems was to not squash prices in
mixedAmount(Looks|Is)Zero. This is correct behaviour in any case.
---
 bin/hledger-check-fancyassertions.hs          |   4 +-
 bin/hledger-combine-balances.hs               |   2 +-
 hledger-lib/Hledger/Data/Account.hs           |   6 +-
 hledger-lib/Hledger/Data/Amount.hs            | 175 ++++++++++++------
 hledger-lib/Hledger/Data/Journal.hs           |  26 +--
 hledger-lib/Hledger/Data/Posting.hs           |   9 +-
 hledger-lib/Hledger/Data/Transaction.hs       |  11 +-
 hledger-lib/Hledger/Read/CsvReader.hs         |   4 +-
 .../Reports/AccountTransactionsReport.hs      |  18 +-
 hledger-lib/Hledger/Reports/BalanceReport.hs  |   6 +-
 hledger-lib/Hledger/Reports/BudgetReport.hs   |   4 +-
 .../Hledger/Reports/MultiBalanceReport.hs     |  24 +--
 hledger-lib/Hledger/Reports/PostingsReport.hs |  29 ++-
 hledger-lib/Hledger/Reports/ReportTypes.hs    |   6 +-
 .../Hledger/Reports/TransactionsReport.hs     |  10 +-
 hledger-lib/Hledger/Utils.hs                  |  24 ++-
 hledger/Hledger/Cli/Commands/Add.hs           |   4 +-
 hledger/Hledger/Cli/Commands/Balancesheet.hs  |   3 +-
 .../Cli/Commands/Balancesheetequity.hs        |   4 +-
 hledger/Hledger/Cli/Commands/Close.hs         |   4 +-
 .../Hledger/Cli/Commands/Incomestatement.hs   |   2 +-
 hledger/Hledger/Cli/Commands/Registermatch.hs |   2 +-
 hledger/Hledger/Cli/Commands/Roi.hs           |  35 ++--
 23 files changed, 235 insertions(+), 177 deletions(-)

diff --git a/bin/hledger-check-fancyassertions.hs b/bin/hledger-check-fancyassertions.hs
index fc2d8cb0f..d0f111218 100755
--- a/bin/hledger-check-fancyassertions.hs
+++ b/bin/hledger-check-fancyassertions.hs
@@ -218,7 +218,7 @@ checkAssertion accounts = checkAssertion'
     evaluate (Account account) =
       fromMaybe H.nullmixedamt $ lookup account accounts
     evaluate (AccountNested account) =
-      sum [m | (a,m) <- accounts, account == a || (a <> pack ":") `isPrefixOf` account]
+      maSum [m | (a,m) <- accounts, account == a || (a <> pack ":") `isPrefixOf` account]
     evaluate (Amount amount) = H.mixed [amount]
 
     -- Add missing amounts (with 0 value), normalise, throw away style
@@ -279,7 +279,7 @@ closingBalances' postings =
 
 -- | Add balances in matching accounts.
 addAccounts :: [(H.AccountName, H.MixedAmount)] -> [(H.AccountName, H.MixedAmount)] -> [(H.AccountName, H.MixedAmount)]
-addAccounts as1 as2 = [ (a, a1 + a2)
+addAccounts as1 as2 = [ (a, a1 `maPlus` a2)
                       | a <- nub (map fst as1 ++ map fst as2)
                       , let a1 = fromMaybe H.nullmixedamt $ lookup a as1
                       , let a2 = fromMaybe H.nullmixedamt $ lookup a as2
diff --git a/bin/hledger-combine-balances.hs b/bin/hledger-combine-balances.hs
index 3e6db032e..8e73735ef 100755
--- a/bin/hledger-combine-balances.hs
+++ b/bin/hledger-combine-balances.hs
@@ -34,7 +34,7 @@ appendReports r1 r2 =
     mergeRows (PeriodicReportRow name amt1 tot1 avg1) (PeriodicReportRow _ amt2 tot2 avg2) =
       PeriodicReportRow { prrName = name
         , prrAmounts = amt1++amt2
-        , prrTotal = tot1+tot2
+        , prrTotal = tot1 `maPlus` tot2
         , prrAverage = averageMixedAmounts [avg1,avg2]
         }
 
diff --git a/hledger-lib/Hledger/Data/Account.hs b/hledger-lib/Hledger/Data/Account.hs
index 97dd7364c..539157837 100644
--- a/hledger-lib/Hledger/Data/Account.hs
+++ b/hledger-lib/Hledger/Data/Account.hs
@@ -65,7 +65,7 @@ accountsFromPostings ps =
   let
     grouped = groupSort [(paccount p,pamount p) | p <- ps]
     counted = [(aname, length amts) | (aname, amts) <- grouped]
-    summed =  [(aname, sumStrict amts) | (aname, amts) <- grouped]  -- always non-empty
+    summed =  [(aname, maSum amts) | (aname, amts) <- grouped]  -- always non-empty
     acctstree      = accountTree "root" $ map fst summed
     acctswithnumps = mapAccounts setnumps    acctstree      where setnumps    a = a{anumpostings=fromMaybe 0 $ lookup (aname a) counted}
     acctswithebals = mapAccounts setebalance acctswithnumps where setebalance a = a{aebalance=lookupJustDef nullmixedamt (aname a) summed}
@@ -122,7 +122,7 @@ sumAccounts a
   | otherwise      = a{aibalance=ibal, asubs=subs}
   where
     subs = map sumAccounts $ asubs a
-    ibal = sum $ aebalance a : map aibalance subs
+    ibal = maSum $ aebalance a : map aibalance subs
 
 -- | Remove all subaccounts below a certain depth.
 clipAccounts :: Int -> Account -> Account
@@ -139,7 +139,7 @@ clipAccountsAndAggregate Nothing  as = as
 clipAccountsAndAggregate (Just d) as = combined
     where
       clipped  = [a{aname=clipOrEllipsifyAccountName (Just d) $ aname a} | a <- as]
-      combined = [a{aebalance=sum $ map aebalance same}
+      combined = [a{aebalance=maSum $ map aebalance same}
                  | same@(a:_) <- groupOn aname clipped]
 {-
 test cases, assuming d=1:
diff --git a/hledger-lib/Hledger/Data/Amount.hs b/hledger-lib/Hledger/Data/Amount.hs
index b62f2c6c5..a01330369 100644
--- a/hledger-lib/Hledger/Data/Amount.hs
+++ b/hledger-lib/Hledger/Data/Amount.hs
@@ -94,6 +94,9 @@ module Hledger.Data.Amount (
   nullmixedamt,
   missingmixedamt,
   mixed,
+  mixedAmount,
+  maAddAmount,
+  maAddAmounts,
   amounts,
   filterMixedAmount,
   filterMixedAmountByCommodity,
@@ -104,12 +107,18 @@ module Hledger.Data.Amount (
   mixedAmountStripPrices,
   -- ** arithmetic
   mixedAmountCost,
+  maNegate,
+  maPlus,
+  maMinus,
+  maSum,
   divideMixedAmount,
   multiplyMixedAmount,
   averageMixedAmounts,
   isNegativeAmount,
   isNegativeMixedAmount,
   mixedAmountIsZero,
+  maIsZero,
+  maIsNonZero,
   mixedAmountLooksZero,
   mixedAmountTotalPriceToUnitPrice,
   -- ** rendering
@@ -138,12 +147,12 @@ import Control.Monad (foldM)
 import Data.Decimal (DecimalRaw(..), decimalPlaces, normalizeDecimal, roundTo)
 import Data.Default (Default(..))
 import Data.Foldable (toList)
-import Data.List (intercalate, intersperse, mapAccumL, partition)
+import Data.List (foldl', intercalate, intersperse, mapAccumL, partition)
 import Data.List.NonEmpty (NonEmpty(..), nonEmpty)
 import qualified Data.Map.Strict as M
 import Data.Maybe (fromMaybe)
 #if !(MIN_VERSION_base(4,11,0))
-import Data.Semigroup ((<>))
+import Data.Semigroup (Semigroup(..))
 #endif
 import qualified Data.Text as T
 import qualified Data.Text.Lazy.Builder as TB
@@ -494,13 +503,26 @@ canonicaliseAmount styles a@Amount{acommodity=c, astyle=s} = a{astyle=s'}
 -------------------------------------------------------------------------------
 -- MixedAmount
 
+instance Semigroup MixedAmount where
+  (<>) = maPlus
+
+instance Monoid MixedAmount where
+  mempty = nullmixedamt
+#if !(MIN_VERSION_base(4,11,0))
+  mappend = (<>)
+#endif
+
 instance Num MixedAmount where
-    fromInteger i = Mixed [fromInteger i]
-    negate (Mixed as) = Mixed $ map negate as
-    (+) (Mixed as) (Mixed bs) = normaliseMixedAmount $ Mixed $ as ++ bs
-    (*)    = error' "error, mixed amounts do not support multiplication" -- PARTIAL:
-    abs    = error' "error, mixed amounts do not support abs"
-    signum = error' "error, mixed amounts do not support signum"
+  fromInteger i = Mixed [fromInteger i]
+  negate = maNegate
+  (+)    = maPlus
+  (*)    = error' "error, mixed amounts do not support multiplication" -- PARTIAL:
+  abs    = error' "error, mixed amounts do not support abs"
+  signum = error' "error, mixed amounts do not support signum"
+
+-- | Get a mixed amount's component amounts.
+amounts :: MixedAmount -> [Amount]
+amounts (Mixed as) = as
 
 -- | The empty mixed amount.
 nullmixedamt :: MixedAmount
@@ -514,6 +536,85 @@ missingmixedamt = Mixed [missingamt]
 mixed :: [Amount] -> MixedAmount
 mixed = normaliseMixedAmount . Mixed
 
+-- | Create a MixedAmount from a single Amount.
+mixedAmount :: Amount -> MixedAmount
+mixedAmount = Mixed . pure
+
+-- | Add an Amount to a MixedAmount, normalising the result.
+maAddAmount :: MixedAmount -> Amount -> MixedAmount
+maAddAmount (Mixed as) a = normaliseMixedAmount . Mixed $ a : as
+
+-- | Add a collection of Amounts to a MixedAmount, normalising the result.
+maAddAmounts :: MixedAmount -> [Amount] -> MixedAmount
+maAddAmounts (Mixed as) bs = bs `seq` normaliseMixedAmount . Mixed $ bs ++ as
+
+-- | Negate mixed amount's quantities (and total prices, if any).
+maNegate :: MixedAmount -> MixedAmount
+maNegate = transformMixedAmount negate
+
+-- | Sum two MixedAmount.
+maPlus :: MixedAmount -> MixedAmount -> MixedAmount
+maPlus (Mixed as) (Mixed bs) = normaliseMixedAmount . Mixed $ as ++ bs
+
+-- | Subtract a MixedAmount from another.
+maMinus :: MixedAmount -> MixedAmount -> MixedAmount
+maMinus a = maPlus a . maNegate
+
+-- | Sum a collection of MixedAmounts.
+maSum :: Foldable t => t MixedAmount -> MixedAmount
+maSum = foldl' maPlus nullmixedamt
+
+-- | Divide a mixed amount's quantities (and total prices, if any) by a constant.
+divideMixedAmount :: Quantity -> MixedAmount -> MixedAmount
+divideMixedAmount n = transformMixedAmount (/n)
+
+-- | Multiply a mixed amount's quantities (and total prices, if any) by a constant.
+multiplyMixedAmount :: Quantity -> MixedAmount -> MixedAmount
+multiplyMixedAmount n = transformMixedAmount (*n)
+
+-- | Apply a function to a mixed amount's quantities (and its total prices, if it has any).
+transformMixedAmount :: (Quantity -> Quantity) -> MixedAmount -> MixedAmount
+transformMixedAmount f = mapMixedAmount (transformAmount f)
+
+-- | Calculate the average of some mixed amounts.
+averageMixedAmounts :: [MixedAmount] -> MixedAmount
+averageMixedAmounts as = fromIntegral (length as) `divideMixedAmount` maSum as
+
+-- | Is this mixed amount negative, if we can tell that unambiguously?
+-- Ie when normalised, are all individual commodity amounts negative ?
+isNegativeMixedAmount :: MixedAmount -> Maybe Bool
+isNegativeMixedAmount m =
+  case amounts $ normaliseMixedAmountSquashPricesForDisplay m of
+    []  -> Just False
+    [a] -> Just $ isNegativeAmount a
+    as | all isNegativeAmount as -> Just True
+    as | not (any isNegativeAmount as) -> Just False
+    _ -> Nothing  -- multiple amounts with different signs
+
+-- | Does this mixed amount appear to be zero when rendered with its display precision?
+-- i.e. does it have zero quantity with no price, zero quantity with a total price (which is also zero),
+-- and zero quantity for each unit price?
+mixedAmountLooksZero :: MixedAmount -> Bool
+mixedAmountLooksZero = all amountLooksZero . amounts . normaliseMixedAmount
+
+-- | Is this mixed amount exactly zero, ignoring its display precision?
+-- i.e. does it have zero quantity with no price, zero quantity with a total price (which is also zero),
+-- and zero quantity for each unit price?
+mixedAmountIsZero :: MixedAmount -> Bool
+mixedAmountIsZero = all amountIsZero . amounts . normaliseMixedAmount
+
+-- | Is this mixed amount exactly zero, ignoring its display precision?
+--
+-- A convenient alias for mixedAmountIsZero.
+maIsZero :: MixedAmount -> Bool
+maIsZero = mixedAmountIsZero
+
+-- | Is this mixed amount non-zero, ignoring its display precision?
+--
+-- A convenient alias for not . mixedAmountIsZero.
+maIsNonZero :: MixedAmount -> Bool
+maIsNonZero = not . mixedAmountIsZero
+
 -- | Simplify a mixed amount's component amounts:
 --
 -- * amounts in the same commodity are combined unless they have different prices or total prices
@@ -581,10 +682,6 @@ sumSimilarAmountsUsingFirstPrice a b = (a + b){aprice=p}
 -- sumSimilarAmountsNotingPriceDifference [] = nullamt
 -- sumSimilarAmountsNotingPriceDifference as = undefined
 
--- | Get a mixed amount's component amounts.
-amounts :: MixedAmount -> [Amount]
-amounts (Mixed as) = as
-
 -- | Filter a mixed amount's component amounts by a predicate.
 filterMixedAmount :: (Amount -> Bool) -> MixedAmount -> MixedAmount
 filterMixedAmount p (Mixed as) = Mixed $ filter p as
@@ -609,42 +706,6 @@ mapMixedAmount f (Mixed as) = Mixed $ map f as
 mixedAmountCost :: MixedAmount -> MixedAmount
 mixedAmountCost = mapMixedAmount amountCost
 
--- | Divide a mixed amount's quantities (and total prices, if any) by a constant.
-divideMixedAmount :: Quantity -> MixedAmount -> MixedAmount
-divideMixedAmount n = mapMixedAmount (divideAmount n)
-
--- | Multiply a mixed amount's quantities (and total prices, if any) by a constant.
-multiplyMixedAmount :: Quantity -> MixedAmount -> MixedAmount
-multiplyMixedAmount n = mapMixedAmount (multiplyAmount n)
-
--- | Calculate the average of some mixed amounts.
-averageMixedAmounts :: [MixedAmount] -> MixedAmount
-averageMixedAmounts [] = 0
-averageMixedAmounts as = fromIntegral (length as) `divideMixedAmount` sum as
-
--- | Is this mixed amount negative, if we can tell that unambiguously?
--- Ie when normalised, are all individual commodity amounts negative ?
-isNegativeMixedAmount :: MixedAmount -> Maybe Bool
-isNegativeMixedAmount m =
-  case amounts $ normaliseMixedAmountSquashPricesForDisplay m of
-    []  -> Just False
-    [a] -> Just $ isNegativeAmount a
-    as | all isNegativeAmount as -> Just True
-    as | not (any isNegativeAmount as) -> Just False
-    _ -> Nothing  -- multiple amounts with different signs
-
--- | Does this mixed amount appear to be zero when rendered with its display precision?
--- i.e. does it have zero quantity with no price, zero quantity with a total price (which is also zero),
--- and zero quantity for each unit price?
-mixedAmountLooksZero :: MixedAmount -> Bool
-mixedAmountLooksZero = all amountLooksZero . amounts . normaliseMixedAmountSquashPricesForDisplay
-
--- | Is this mixed amount exactly to be zero, ignoring its display precision?
--- i.e. does it have zero quantity with no price, zero quantity with a total price (which is also zero),
--- and zero quantity for each unit price?
-mixedAmountIsZero :: MixedAmount -> Bool
-mixedAmountIsZero = all amountIsZero . amounts . normaliseMixedAmountSquashPricesForDisplay
-
 -- -- | MixedAmount derived Eq instance in Types.hs doesn't know that we
 -- -- want $0 = EUR0 = 0. Yet we don't want to drag all this code over there.
 -- -- For now, use this when cross-commodity zero equality is important.
@@ -888,18 +949,18 @@ tests_Amount = tests "Amount" [
   ,tests "MixedAmount" [
 
      test "adding mixed amounts to zero, the commodity and amount style are preserved" $
-      sum (map (Mixed . (:[]))
-               [usd 1.25
-               ,usd (-1) `withPrecision` Precision 3
-               ,usd (-0.25)
-               ])
+      maSum (map mixedAmount
+        [usd 1.25
+        ,usd (-1) `withPrecision` Precision 3
+        ,usd (-0.25)
+        ])
         @?= Mixed [usd 0 `withPrecision` Precision 3]
 
     ,test "adding mixed amounts with total prices" $ do
-      sum (map (Mixed . (:[]))
-       [usd 1 @@ eur 1
-       ,usd (-2) @@ eur 1
-       ])
+      maSum (map mixedAmount
+        [usd 1 @@ eur 1
+        ,usd (-2) @@ eur 1
+        ])
         @?= Mixed [usd (-1) @@ eur 2 ]
 
     ,test "showMixedAmount" $ do
diff --git a/hledger-lib/Hledger/Data/Journal.hs b/hledger-lib/Hledger/Data/Journal.hs
index 537c4c53d..867140e42 100644
--- a/hledger-lib/Hledger/Data/Journal.hs
+++ b/hledger-lib/Hledger/Data/Journal.hs
@@ -765,14 +765,14 @@ withRunningBalance f = ask >>= lift . lift . f
 -- | Get this account's current exclusive running balance.
 getRunningBalanceB :: AccountName -> Balancing s MixedAmount
 getRunningBalanceB acc = withRunningBalance $ \BalancingState{bsBalances} -> do
-  fromMaybe 0 <$> H.lookup bsBalances acc
+  fromMaybe nullmixedamt <$> H.lookup bsBalances acc
 
 -- | Add this amount to this account's exclusive running balance.
 -- Returns the new running balance.
 addToRunningBalanceB :: AccountName -> MixedAmount -> Balancing s MixedAmount
 addToRunningBalanceB acc amt = withRunningBalance $ \BalancingState{bsBalances} -> do
-  old <- fromMaybe 0 <$> H.lookup bsBalances acc
-  let new = old + amt
+  old <- fromMaybe nullmixedamt <$> H.lookup bsBalances acc
+  let new = maPlus old amt
   H.insert bsBalances acc new
   return new
 
@@ -780,9 +780,9 @@ addToRunningBalanceB acc amt = withRunningBalance $ \BalancingState{bsBalances}
 -- Returns the change in exclusive running balance.
 setRunningBalanceB :: AccountName -> MixedAmount -> Balancing s MixedAmount
 setRunningBalanceB acc amt = withRunningBalance $ \BalancingState{bsBalances} -> do
-  old <- fromMaybe 0 <$> H.lookup bsBalances acc
+  old <- fromMaybe nullmixedamt <$> H.lookup bsBalances acc
   H.insert bsBalances acc amt
-  return $ amt - old
+  return $ maMinus amt old
 
 -- | Set this account's exclusive running balance to whatever amount
 -- makes its *inclusive* running balance (the sum of exclusive running
@@ -790,13 +790,13 @@ setRunningBalanceB acc amt = withRunningBalance $ \BalancingState{bsBalances} ->
 -- Returns the change in exclusive running balance.
 setInclusiveRunningBalanceB :: AccountName -> MixedAmount -> Balancing s MixedAmount
 setInclusiveRunningBalanceB acc newibal = withRunningBalance $ \BalancingState{bsBalances} -> do
-  oldebal  <- fromMaybe 0 <$> H.lookup bsBalances acc
+  oldebal  <- fromMaybe nullmixedamt <$> H.lookup bsBalances acc
   allebals <- H.toList bsBalances
   let subsibal =  -- sum of any subaccounts' running balances
-        sum $ map snd $ filter ((acc `isAccountNamePrefixOf`).fst) allebals
-  let newebal = newibal - subsibal
+        maSum . map snd $ filter ((acc `isAccountNamePrefixOf`).fst) allebals
+  let newebal = maMinus newibal subsibal
   H.insert bsBalances acc newebal
-  return $ newebal - oldebal
+  return $ maMinus newebal oldebal
 
 -- | Update (overwrite) this transaction in the balancing state.
 updateTransactionB :: Transaction -> Balancing s ()
@@ -909,7 +909,7 @@ addOrAssignAmountAndCheckAssertionB p@Posting{paccount=acc, pamount=amt, pbalanc
         False -> do
           oldbalothercommodities <- filterMixedAmount ((acommodity baamount /=) . acommodity) <$> getRunningBalanceB acc
           let assignedbalthiscommodity = Mixed [baamount]
-              newbal = oldbalothercommodities + assignedbalthiscommodity
+              newbal = maPlus oldbalothercommodities assignedbalthiscommodity
           diff <- (if bainclusive then setInclusiveRunningBalanceB else setRunningBalanceB) acc newbal
           return (diff,newbal)
       let p' = p{pamount=diff, poriginal=Just $ originalPosting p}
@@ -961,9 +961,9 @@ checkBalanceAssertionOneCommodityB p@Posting{paccount=assertedacct} assertedamt
       -- sum the running balances of this account and any of its subaccounts seen so far
       withRunningBalance $ \BalancingState{bsBalances} ->
         H.foldM
-          (\ibal (acc, amt) -> return $ ibal +
-            if assertedacct==acc || assertedacct `isAccountNamePrefixOf` acc then amt else 0)
-          0
+          (\ibal (acc, amt) -> return $
+            if assertedacct==acc || assertedacct `isAccountNamePrefixOf` acc then maPlus ibal amt else ibal)
+          nullmixedamt
           bsBalances
     else return actualbal
   let
diff --git a/hledger-lib/Hledger/Data/Posting.hs b/hledger-lib/Hledger/Data/Posting.hs
index 7e2679ce8..866fb6698 100644
--- a/hledger-lib/Hledger/Data/Posting.hs
+++ b/hledger-lib/Hledger/Data/Posting.hs
@@ -75,15 +75,16 @@ import Control.Monad (foldM)
 import Data.Foldable (asum)
 import Data.List.Extra (nubSort)
 import qualified Data.Map as M
-import Data.Maybe
+import Data.Maybe (fromMaybe, isJust)
 import Data.MemoUgly (memo)
+import Data.List (foldl')
 #if !(MIN_VERSION_base(4,11,0))
 import Data.Monoid
 #endif
 import Data.Text (Text)
 import qualified Data.Text as T
-import Data.Time.Calendar
-import Safe
+import Data.Time.Calendar (Day)
+import Safe (headDef)
 
 import Hledger.Utils
 import Hledger.Data.Types
@@ -197,7 +198,7 @@ accountNamesFromPostings :: [Posting] -> [AccountName]
 accountNamesFromPostings = nubSort . map paccount
 
 sumPostings :: [Posting] -> MixedAmount
-sumPostings = sumStrict . map pamount
+sumPostings = foldl' (\amt p -> maPlus amt $ pamount p) nullmixedamt
 
 -- | Remove all prices of a posting
 removePrices :: Posting -> Posting
diff --git a/hledger-lib/Hledger/Data/Transaction.hs b/hledger-lib/Hledger/Data/Transaction.hs
index e839954dc..290344741 100644
--- a/hledger-lib/Hledger/Data/Transaction.hs
+++ b/hledger-lib/Hledger/Data/Transaction.hs
@@ -471,9 +471,9 @@ inferBalancingAmount styles t@Transaction{tpostings=ps}
         in Right (t{tpostings=map fst psandinferredamts}, inferredacctsandamts)
   where
     (amountfulrealps, amountlessrealps) = partition hasAmount (realPostings t)
-    realsum = sumStrict $ map pamount amountfulrealps
+    realsum = sumPostings amountfulrealps
     (amountfulbvps, amountlessbvps) = partition hasAmount (balancedVirtualPostings t)
-    bvsum = sumStrict $ map pamount amountfulbvps
+    bvsum = sumPostings amountfulbvps
 
     inferamount :: Posting -> (Posting, Maybe MixedAmount)
     inferamount p =
@@ -490,7 +490,7 @@ inferBalancingAmount styles t@Transaction{tpostings=ps}
               -- 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 $ mixedAmountCost (-a)
+              a' = styleMixedAmount styles . normaliseMixedAmount . mixedAmountCost $ maNegate 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
@@ -542,10 +542,9 @@ priceInferrerFor :: Transaction -> PostingType -> (Posting -> Posting)
 priceInferrerFor t pt = inferprice
   where
     postings       = filter ((==pt).ptype) $ tpostings t
-    pmixedamounts  = map pamount postings
-    pamounts       = concatMap amounts pmixedamounts
+    pamounts       = concatMap (amounts . pamount) postings
     pcommodities   = map acommodity pamounts
-    sumamounts     = amounts $ sumStrict pmixedamounts -- sum normalises to one amount per commodity & price
+    sumamounts     = amounts $ sumPostings postings  -- sum normalises to one amount per commodity & price
     sumcommodities = map acommodity sumamounts
     sumprices      = filter (/=Nothing) $ map aprice sumamounts
     caninferprices = length sumcommodities == 2 && null sumprices
diff --git a/hledger-lib/Hledger/Read/CsvReader.hs b/hledger-lib/Hledger/Read/CsvReader.hs
index 6623e001a..2a9fdbb7c 100644
--- a/hledger-lib/Hledger/Read/CsvReader.hs
+++ b/hledger-lib/Hledger/Read/CsvReader.hs
@@ -995,7 +995,7 @@ getAmount rules record currency p1IsVirtual n =
                           , let a = parseAmount rules record currency v
                           -- With amount/amount-in/amount-out, in posting 2,
                           -- flip the sign and convert to cost, as they did before 1.17
-                          , let a' = if f `elem` unnumberedfieldnames && n==2 then mixedAmountCost (-a) else a
+                          , let a' = if f `elem` unnumberedfieldnames && n==2 then mixedAmountCost (maNegate a) else a
                           ]
 
     -- if any of the numbered field names are present, discard all the unnumbered ones
@@ -1013,7 +1013,7 @@ getAmount rules record currency p1IsVirtual n =
   in case -- dbg0 ("amounts for posting "++show n)
           assignments'' of
       [] -> Nothing
-      [(f,a)] | "-out" `T.isSuffixOf` f -> Just (-a)  -- for -out fields, flip the sign
+      [(f,a)] | "-out" `T.isSuffixOf` f -> Just (maNegate a)  -- for -out fields, flip the sign
       [(_,a)] -> Just a
       fs      -> error' . T.unpack . T.unlines $ [  -- PARTIAL:
          "multiple non-zero amounts or multiple zero amounts assigned,"
diff --git a/hledger-lib/Hledger/Reports/AccountTransactionsReport.hs b/hledger-lib/Hledger/Reports/AccountTransactionsReport.hs
index 6b9c531ba..49b717f97 100644
--- a/hledger-lib/Hledger/Reports/AccountTransactionsReport.hs
+++ b/hledger-lib/Hledger/Reports/AccountTransactionsReport.hs
@@ -1,4 +1,6 @@
-{-# LANGUAGE OverloadedStrings, RecordWildCards, FlexibleInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards   #-}
 {-|
 
 An account-centric transactions report.
@@ -15,12 +17,12 @@ module Hledger.Reports.AccountTransactionsReport (
 )
 where
 
-import Data.List
-import Data.Ord
-import Data.Maybe
+import Data.List (mapAccumL, nub, partition, sortBy)
+import Data.Ord (comparing)
+import Data.Maybe (catMaybes, fromMaybe)
 import Data.Text (Text)
 import qualified Data.Text as T
-import Data.Time.Calendar
+import Data.Time.Calendar (Day)
 
 import Hledger.Data
 import Hledger.Query
@@ -145,7 +147,7 @@ accountTransactionsReport rspec@ReportSpec{rsOpts=ropts} j reportq thisacctq = i
     filtertxns = txn_dates_ ropts
 
     items = reverse $
-            accountTransactionsReportItems reportq' thisacctq startbal negate $
+            accountTransactionsReportItems reportq' thisacctq startbal maNegate $
             (if filtertxns then filter (reportq' `matchesTransaction`) else id) $
             ts5
 
@@ -179,8 +181,8 @@ accountTransactionsReportItem reportq thisacctq signfn bal torig = balItem
                   otheracctstr | thisacctq == None  = summarisePostingAccounts reportps     -- no current account ? summarise all matched postings
                                | numotheraccts == 0 = summarisePostingAccounts thisacctps   -- only postings to current account ? summarise those
                                | otherwise          = summarisePostingAccounts otheracctps  -- summarise matched postings to other account(s)
-                  a = signfn $ negate $ sum $ map pamount thisacctps
-                  b = bal + a
+                  a = signfn . maNegate $ sumPostings thisacctps
+                  b = bal `maPlus` a
 
 -- | What is the transaction's date in the context of a particular account
 -- (specified with a query) and report query, as in an account register ?
diff --git a/hledger-lib/Hledger/Reports/BalanceReport.hs b/hledger-lib/Hledger/Reports/BalanceReport.hs
index 78f67881a..71ba82802 100644
--- a/hledger-lib/Hledger/Reports/BalanceReport.hs
+++ b/hledger-lib/Hledger/Reports/BalanceReport.hs
@@ -112,7 +112,7 @@ tests_BalanceReport = tests "BalanceReport" [
     tests "balanceReport" [
 
      test "no args, null journal" $
-     (defreportspec, nulljournal) `gives` ([], 0)
+     (defreportspec, nulljournal) `gives` ([], nullmixedamt)
 
     ,test "no args, sample journal" $
      (defreportspec, samplejournal) `gives`
@@ -162,7 +162,7 @@ tests_BalanceReport = tests "BalanceReport" [
 
     ,test "with date:" $
      (defreportspec{rsQuery=Date $ DateSpan (Just $ fromGregorian 2009 01 01) (Just $ fromGregorian 2010 01 01)}, samplejournal2) `gives`
-      ([], 0)
+      ([], nullmixedamt)
 
     ,test "with date2:" $
      (defreportspec{rsQuery=Date2 $ DateSpan (Just $ fromGregorian 2009 01 01) (Just $ fromGregorian 2010 01 01)}, samplejournal2) `gives`
@@ -202,7 +202,7 @@ tests_BalanceReport = tests "BalanceReport" [
 
      ,test "with period on an unpopulated period" $
       (defreportspec{rsOpts=defreportopts{period_= PeriodBetween (fromGregorian 2008 1 2) (fromGregorian 2008 1 3)}}, samplejournal) `gives`
-       ([], 0)
+       ([], nullmixedamt)
 
 
 
diff --git a/hledger-lib/Hledger/Reports/BudgetReport.hs b/hledger-lib/Hledger/Reports/BudgetReport.hs
index 1081ab4ee..eab7b8ab7 100644
--- a/hledger-lib/Hledger/Reports/BudgetReport.hs
+++ b/hledger-lib/Hledger/Reports/BudgetReport.hs
@@ -206,7 +206,7 @@ combineBudgetAndActual ropts j
     sortedrows :: [BudgetReportRow] = sortRowsLike (mbrsorted unbudgetedrows ++ mbrsorted rows') rows
       where
         (unbudgetedrows, rows') = partition ((==unbudgetedAccountName) . prrFullName) rows
-        mbrsorted = map prrFullName . sortRows ropts j . map (fmap $ fromMaybe 0 . fst)
+        mbrsorted = map prrFullName . sortRows ropts j . map (fmap $ fromMaybe nullmixedamt . fst)
         rows = rows1 ++ rows2
 
     -- TODO: grand total & average shows 0% when there are no actual amounts, inconsistent with other cells
@@ -244,7 +244,7 @@ budgetReportAsText ropts@ReportOpts{..} budgetr = TB.toLazyText $
 
     displayCell (actual, budget) = (showamt actual', budgetAndPerc <$> budget)
       where
-        actual' = fromMaybe 0 actual
+        actual' = fromMaybe nullmixedamt actual
         budgetAndPerc b = (showamt b, showper <$> percentage actual' b)
         showamt = (\(WideBuilder b w) -> (TL.toStrict $ TB.toLazyText b, w)) . showMixedAmountB oneLine{displayColour=color_, displayMaxWidth=Just 32}
         showper p = let str = T.pack (show $ roundTo 0 p) in (str, T.length str)
diff --git a/hledger-lib/Hledger/Reports/MultiBalanceReport.hs b/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
index 3d5362a90..bcf72b866 100644
--- a/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
+++ b/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
@@ -174,7 +174,7 @@ compoundBalanceReportWith rspec' j priceoracle subreportspecs = cbr
         (r:rs) -> sconcat $ fmap subreportTotal (r:|rs)
       where
         subreportTotal (_, sr, increasestotal) =
-            (if increasestotal then id else fmap negate) $ prTotals sr
+            (if increasestotal then id else fmap maNegate) $ prTotals sr
 
     cbr = CompoundPeriodicReport "" (M.keys colps) subreports overalltotals
 
@@ -338,7 +338,7 @@ generateMultiBalanceReport rspec@ReportSpec{rsOpts=ropts} j priceoracle colps st
     displaynames = dbg5 "displaynames" $ displayedAccounts rspec matrix
 
     -- All the rows of the report.
-    rows = dbg5 "rows" . (if invert_ ropts then map (fmap negate) else id)  -- Negate amounts if applicable
+    rows = dbg5 "rows" . (if invert_ ropts then map (fmap maNegate) else id)  -- Negate amounts if applicable
              $ buildReportRows ropts displaynames matrix
 
     -- Calculate column totals
@@ -357,7 +357,7 @@ buildReportRows :: ReportOpts
                 -> HashMap AccountName DisplayName
                 -> HashMap AccountName (Map DateSpan Account)
                 -> [MultiBalanceReportRow]
-buildReportRows ropts displaynames = 
+buildReportRows ropts displaynames =
   toList . HM.mapMaybeWithKey mkRow  -- toList of HashMap's Foldable instance - does not sort consistently
   where
     mkRow name accts = do
@@ -369,8 +369,8 @@ buildReportRows ropts displaynames =
         -- These are always simply the sum/average of the displayed row amounts.
         -- Total for a cumulative/historical report is always the last column.
         rowtot = case balancetype_ ropts of
-            PeriodChange -> sum rowbals
-            _            -> lastDef 0 rowbals
+            PeriodChange -> maSum rowbals
+            _            -> lastDef nullmixedamt rowbals
         rowavg = averageMixedAmounts rowbals
     balance = case accountlistmode_ ropts of ALTree -> aibalance; ALFlat -> aebalance
 
@@ -439,7 +439,7 @@ sortRows ropts j
         -- Set the inclusive balance of an account from the rows, or sum the
         -- subaccounts if it's not present
         accounttreewithbals = mapAccounts setibalance accounttree
-        setibalance a = a{aibalance = maybe (sum . map aibalance $ asubs a) prrTotal $
+        setibalance a = a{aibalance = maybe (maSum . map aibalance $ asubs a) prrTotal $
                                           HM.lookup (aname a) rowMap}
         sortedaccounttree = sortAccountTreeByAmount (fromMaybe NormallyPositive $ normalbalance_ ropts) accounttreewithbals
         sortedanames = map aname $ drop 1 $ flattenAccounts sortedaccounttree
@@ -470,14 +470,14 @@ calculateTotalsRow ropts rows =
 
     colamts = transpose . map prrAmounts $ filter isTopRow rows
 
-    coltotals :: [MixedAmount] = dbg5 "coltotals" $ map sum colamts
+    coltotals :: [MixedAmount] = dbg5 "coltotals" $ map maSum colamts
 
     -- Calculate the grand total and average. These are always the sum/average
     -- of the column totals.
     -- Total for a cumulative/historical report is always the last column.
     grandtotal = case balancetype_ ropts of
-        PeriodChange -> sum coltotals
-        _            -> lastDef 0 coltotals
+        PeriodChange -> maSum coltotals
+        _            -> lastDef nullmixedamt coltotals
     grandaverage = averageMixedAmounts coltotals
 
 -- | Map the report rows to percentages if needed
@@ -535,12 +535,12 @@ perdivide a b = fromMaybe (error' errmsg) $ do  -- PARTIAL:
 -- in scanl, so other properties (such as anumpostings) stay in the right place
 sumAcct :: Account -> Account -> Account
 sumAcct Account{aibalance=i1,aebalance=e1} a@Account{aibalance=i2,aebalance=e2} =
-    a{aibalance = i1 + i2, aebalance = e1 + e2}
+    a{aibalance = i1 `maPlus` i2, aebalance = e1 `maPlus` e2}
 
 -- Subtract the values in one account from another. Should be left-biased.
 subtractAcct :: Account -> Account -> Account
 subtractAcct a@Account{aibalance=i1,aebalance=e1} Account{aibalance=i2,aebalance=e2} =
-    a{aibalance = i1 - i2, aebalance = e1 - e2}
+    a{aibalance = i1 `maMinus` i2, aebalance = e1 `maMinus` e2}
 
 -- | Extract period changes from a cumulative list
 periodChanges :: Account -> Map k Account -> Map k Account
@@ -586,7 +586,7 @@ tests_MultiBalanceReport = tests "MultiBalanceReport" [
   in
    tests "multiBalanceReport" [
       test "null journal"  $
-      (defreportspec, nulljournal) `gives` ([], Mixed [nullamt])
+      (defreportspec, nulljournal) `gives` ([], nullmixedamt)
 
      ,test "with -H on a populated period"  $
       (defreportspec{rsOpts=defreportopts{period_= PeriodBetween (fromGregorian 2008 1 1) (fromGregorian 2008 1 2), balancetype_=HistoricalBalance}}, samplejournal) `gives`
diff --git a/hledger-lib/Hledger/Reports/PostingsReport.hs b/hledger-lib/Hledger/Reports/PostingsReport.hs
index 297d1f621..4346dff32 100644
--- a/hledger-lib/Hledger/Reports/PostingsReport.hs
+++ b/hledger-lib/Hledger/Reports/PostingsReport.hs
@@ -4,11 +4,11 @@ Postings report, used by the register command.
 
 -}
 
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE FlexibleInstances   #-}
+{-# LANGUAGE OverloadedStrings   #-}
+{-# LANGUAGE RecordWildCards     #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TupleSections #-}
+{-# LANGUAGE TupleSections       #-}
 
 module Hledger.Reports.PostingsReport (
   PostingsReport,
@@ -21,11 +21,11 @@ module Hledger.Reports.PostingsReport (
 )
 where
 
-import Data.List
+import Data.List (nub, sortOn)
 import Data.List.Extra (nubSort)
-import Data.Maybe
+import Data.Maybe (fromMaybe, isJust, isNothing)
 import Data.Text (Text)
-import Data.Time.Calendar
+import Data.Time.Calendar (Day, addDays)
 import Safe (headMay, lastMay)
 
 import Hledger.Data
@@ -101,12 +101,11 @@ postingsReport rspec@ReportSpec{rsOpts=ropts@ReportOpts{..}} j = items
           -- of --value on reports".
           -- XXX balance report doesn't value starting balance.. should this ?
           historical = balancetype_ == HistoricalBalance
-          startbal | average_  = if historical then precedingavg else 0
-                   | otherwise = if historical then precedingsum else 0
+          startbal | average_  = if historical then precedingavg else nullmixedamt
+                   | otherwise = if historical then precedingsum else nullmixedamt
             where
               precedingsum = sumPostings $ map (pvalue daybeforereportstart) precedingps
-              precedingavg | null precedingps = 0
-                           | otherwise        = divideMixedAmount (fromIntegral $ length precedingps) precedingsum
+              precedingavg = divideMixedAmount (fromIntegral $ length precedingps) precedingsum
               daybeforereportstart =
                 maybe (error' "postingsReport: expected a non-empty journal")  -- PARTIAL: shouldn't happen
                 (addDays (-1))
@@ -121,8 +120,8 @@ postingsReport rspec@ReportSpec{rsOpts=ropts@ReportOpts{..}} j = items
 -- and return the new average/total.
 registerRunningCalculationFn :: ReportOpts -> (Int -> MixedAmount -> MixedAmount -> MixedAmount)
 registerRunningCalculationFn ropts
-  | average_ ropts = \i avg amt -> avg + divideMixedAmount (fromIntegral i) (amt - avg)
-  | otherwise      = \_ bal amt -> bal + amt
+  | average_ ropts = \i avg amt -> avg `maPlus` divideMixedAmount (fromIntegral i) (amt `maMinus` avg)
+  | otherwise      = \_ bal amt -> bal `maPlus` amt
 
 -- | Find postings matching a given query, within a given date span,
 -- and also any similarly-matched postings before that date span.
@@ -218,7 +217,7 @@ summarisePostingsInDateSpan (DateSpan b e) wd mdepth showempty ps
     e' = fromMaybe (maybe (addDays 1 nulldate) postingdate $ lastMay ps) e
     summaryp = nullposting{pdate=Just b'}
     clippedanames = nub $ map (clipAccountName mdepth) anames
-    summaryps | mdepth == Just 0 = [summaryp{paccount="...",pamount=sum $ map pamount ps}]
+    summaryps | mdepth == Just 0 = [summaryp{paccount="...",pamount=sumPostings ps}]
               | otherwise        = [summaryp{paccount=a,pamount=balance a} | a <- clippedanames]
     summarypes = map (, e') $ (if showempty then id else filter (not . mixedAmountLooksZero . pamount)) summaryps
     anames = nubSort $ map paccount ps
@@ -230,7 +229,7 @@ summarisePostingsInDateSpan (DateSpan b e) wd mdepth showempty ps
         isclipped a = maybe True (accountNameLevel a >=) mdepth
 
 negatePostingAmount :: Posting -> Posting
-negatePostingAmount p = p { pamount = negate $ pamount p }
+negatePostingAmount p = p { pamount = maNegate $ pamount p }
 
 
 -- tests
diff --git a/hledger-lib/Hledger/Reports/ReportTypes.hs b/hledger-lib/Hledger/Reports/ReportTypes.hs
index e982e2edd..d985b32df 100644
--- a/hledger-lib/Hledger/Reports/ReportTypes.hs
+++ b/hledger-lib/Hledger/Reports/ReportTypes.hs
@@ -98,11 +98,11 @@ data PeriodicReportRow a b =
   , prrAverage :: b    -- The average of this row's values.
   } deriving (Show, Functor, Generic, ToJSON)
 
-instance Num b => Semigroup (PeriodicReportRow a b) where
+instance Semigroup b => Semigroup (PeriodicReportRow a b) where
   (PeriodicReportRow _ amts1 t1 a1) <> (PeriodicReportRow n2 amts2 t2 a2) =
-      PeriodicReportRow n2 (sumPadded amts1 amts2) (t1 + t2) (a1 + a2)
+      PeriodicReportRow n2 (sumPadded amts1 amts2) (t1 <> t2) (a1 <> a2)
     where
-      sumPadded (a:as) (b:bs) = (a + b) : sumPadded as bs
+      sumPadded (a:as) (b:bs) = (a <> b) : sumPadded as bs
       sumPadded as     []     = as
       sumPadded []     bs     = bs
 
diff --git a/hledger-lib/Hledger/Reports/TransactionsReport.hs b/hledger-lib/Hledger/Reports/TransactionsReport.hs
index a6cd1a37a..a469b52d6 100644
--- a/hledger-lib/Hledger/Reports/TransactionsReport.hs
+++ b/hledger-lib/Hledger/Reports/TransactionsReport.hs
@@ -1,4 +1,6 @@
-{-# LANGUAGE OverloadedStrings, RecordWildCards, FlexibleInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards   #-}
 {-|
 
 A transactions report. Like an EntriesReport, but with more
@@ -21,10 +23,10 @@ module Hledger.Reports.TransactionsReport (
 )
 where
 
-import Data.List
+import Data.List (sortBy)
 import Data.List.Extra (nubSort)
+import Data.Ord (comparing)
 import Data.Text (Text)
-import Data.Ord
 
 import Hledger.Data
 import Hledger.Query
@@ -99,7 +101,7 @@ filterTransactionsReportByCommodity c =
         startbal = filterMixedAmountByCommodity c $ triBalance i
         go _ [] = []
         go bal ((t,t2,s,o,amt,_):is) = (t,t2,s,o,amt,bal'):go bal' is
-          where bal' = bal + amt
+          where bal' = bal `maPlus` amt
 
 -- tests
 
diff --git a/hledger-lib/Hledger/Utils.hs b/hledger-lib/Hledger/Utils.hs
index e8f319926..b4d41840b 100644
--- a/hledger-lib/Hledger/Utils.hs
+++ b/hledger-lib/Hledger/Utils.hs
@@ -4,7 +4,9 @@ Standard imports and utilities which are useful everywhere, or needed low
 in the module hierarchy. This is the bottom of hledger's module graph.
 
 -}
-{-# LANGUAGE OverloadedStrings, LambdaCase #-}
+{-# LANGUAGE CPP               #-}
+{-# LANGUAGE LambdaCase        #-}
+{-# LANGUAGE OverloadedStrings #-}
 
 module Hledger.Utils (---- provide these frequently used modules - or not, for clearer api:
                           -- module Control.Monad,
@@ -35,25 +37,21 @@ module Hledger.Utils (---- provide these frequently used modules - or not, for c
 where
 
 import Control.Monad (liftM, when)
--- import Data.Char
 import Data.FileEmbed (makeRelativeToProject, embedStringFile)
-import Data.List
--- import Data.Maybe
--- import Data.PPrint
+import Data.List (foldl', foldl1')
 -- import Data.String.Here (hereFile)
 import Data.Text (Text)
 import qualified Data.Text.IO as T
-import Data.Time.Clock
-import Data.Time.LocalTime
--- import Data.Text (Text)
--- import qualified Data.Text as T
+import Data.Time.Clock (getCurrentTime)
+import Data.Time.LocalTime (LocalTime, ZonedTime, getCurrentTimeZone,
+                            utcToLocalTime, utcToZonedTime)
 -- import Language.Haskell.TH.Quote (QuasiQuoter(..))
 import Language.Haskell.TH.Syntax (Q, Exp)
 import System.Directory (getHomeDirectory)
-import System.FilePath((</>), isRelative)
+import System.FilePath (isRelative, (</>))
 import System.IO
--- import Text.Printf
--- import qualified Data.Map as Map
+  (Handle, IOMode (..), hGetEncoding, hSetEncoding, hSetNewlineMode,
+   openFile, stdin, universalNewlineMode, utf8_bom)
 
 import Hledger.Utils.Debug
 import Hledger.Utils.Parse
@@ -160,7 +158,7 @@ expandPath :: FilePath -> FilePath -> IO FilePath -- general type sig for use in
 expandPath _ "-" = return "-"
 expandPath curdir p = (if isRelative p then (curdir </>) else id) `liftM` expandHomePath p
 -- PARTIAL:
-  
+
 -- | Expand user home path indicated by tilde prefix
 expandHomePath :: FilePath -> IO FilePath
 expandHomePath = \case
diff --git a/hledger/Hledger/Cli/Commands/Add.hs b/hledger/Hledger/Cli/Commands/Add.hs
index 2cd37dced..5b9802e56 100644
--- a/hledger/Hledger/Cli/Commands/Add.hs
+++ b/hledger/Hledger/Cli/Commands/Add.hs
@@ -360,8 +360,8 @@ amountAndCommentWizard PrevInput{..} EntryState{..} = do
         c <- T.pack <$> fromMaybe "" `fmap` optional (char ';' >> many anySingle)
         -- eof
         return (a,c)
-      balancingamt = negate $ sum $ map pamount realps where realps = filter isReal esPostings
-      balancingamtfirstcommodity = Mixed $ take 1 $ amounts balancingamt
+      balancingamt = maNegate . sumPostings $ filter isReal esPostings
+      balancingamtfirstcommodity = Mixed . take 1 $ amounts balancingamt
       showamt =
         showMixedAmount . mixedAmountSetPrecision
                   -- what should this be ?
diff --git a/hledger/Hledger/Cli/Commands/Balancesheet.hs b/hledger/Hledger/Cli/Commands/Balancesheet.hs
index 5bc817c97..da51b561f 100644
--- a/hledger/Hledger/Cli/Commands/Balancesheet.hs
+++ b/hledger/Hledger/Cli/Commands/Balancesheet.hs
@@ -33,7 +33,7 @@ balancesheetSpec = CompoundBalanceCommandSpec {
       cbcsubreporttitle="Liabilities"
      ,cbcsubreportquery=journalLiabilityAccountQuery
      ,cbcsubreportoptions=(\ropts -> ropts{normalbalance_=Just NormallyNegative})
-     ,cbcsubreporttransform=fmap negate
+     ,cbcsubreporttransform=fmap maNegate
      ,cbcsubreportincreasestotal=False
      }
     ],
@@ -45,4 +45,3 @@ balancesheetmode = compoundBalanceCommandMode balancesheetSpec
 
 balancesheet :: CliOpts -> Journal -> IO ()
 balancesheet = compoundBalanceCommand balancesheetSpec
-
diff --git a/hledger/Hledger/Cli/Commands/Balancesheetequity.hs b/hledger/Hledger/Cli/Commands/Balancesheetequity.hs
index fe3170b86..d7f62568c 100644
--- a/hledger/Hledger/Cli/Commands/Balancesheetequity.hs
+++ b/hledger/Hledger/Cli/Commands/Balancesheetequity.hs
@@ -34,14 +34,14 @@ balancesheetequitySpec = CompoundBalanceCommandSpec {
       cbcsubreporttitle="Liabilities"
      ,cbcsubreportquery=journalLiabilityAccountQuery
      ,cbcsubreportoptions=(\ropts -> ropts{normalbalance_=Just NormallyNegative})
-     ,cbcsubreporttransform=fmap negate
+     ,cbcsubreporttransform=fmap maNegate
      ,cbcsubreportincreasestotal=False
      }
     ,CBCSubreportSpec{
       cbcsubreporttitle="Equity"
      ,cbcsubreportquery=journalEquityAccountQuery
      ,cbcsubreportoptions=(\ropts -> ropts{normalbalance_=Just NormallyNegative})
-     ,cbcsubreporttransform=fmap negate
+     ,cbcsubreporttransform=fmap maNegate
      ,cbcsubreportincreasestotal=False
      }
     ],
diff --git a/hledger/Hledger/Cli/Commands/Close.hs b/hledger/Hledger/Cli/Commands/Close.hs
index 911ab2fe9..3bab077c9 100755
--- a/hledger/Hledger/Cli/Commands/Close.hs
+++ b/hledger/Hledger/Cli/Commands/Close.hs
@@ -89,7 +89,7 @@ close CliOpts{rawopts_=rawopts, reportspec_=rspec} j = do
 
     -- the balances to close
     (acctbals,_) = balanceReport rspec_ j
-    totalamt = sum $ map (\(_,_,_,b) -> normalise b) acctbals
+    totalamt = maSum $ map (\(_,_,_,b) -> normalise b) acctbals
 
     -- since balance assertion amounts are required to be exact, the
     -- amounts in opening/closing transactions should be too (#941, #1137)
@@ -150,7 +150,7 @@ close CliOpts{rawopts_=rawopts, reportspec_=rspec} j = do
                            , let commoditysum = (sum bs)]
         , (b, mcommoditysum) <- bs'
         ]
-      ++ [posting{paccount=openingacct, pamount=if explicit then mapMixedAmount precise (negate totalamt) else missingmixedamt} | not interleaved]
+      ++ [posting{paccount=openingacct, pamount=if explicit then mapMixedAmount precise (maNegate totalamt) else missingmixedamt} | not interleaved]
 
   -- print them
   when closing . T.putStr $ showTransaction closingtxn
diff --git a/hledger/Hledger/Cli/Commands/Incomestatement.hs b/hledger/Hledger/Cli/Commands/Incomestatement.hs
index c6e7a14cb..83ab577b7 100644
--- a/hledger/Hledger/Cli/Commands/Incomestatement.hs
+++ b/hledger/Hledger/Cli/Commands/Incomestatement.hs
@@ -24,7 +24,7 @@ incomestatementSpec = CompoundBalanceCommandSpec {
       cbcsubreporttitle="Revenues"
      ,cbcsubreportquery=journalRevenueAccountQuery
      ,cbcsubreportoptions=(\ropts -> ropts{normalbalance_=Just NormallyNegative})
-     ,cbcsubreporttransform=fmap negate
+     ,cbcsubreporttransform=fmap maNegate
      ,cbcsubreportincreasestotal=True
      }
     ,CBCSubreportSpec{
diff --git a/hledger/Hledger/Cli/Commands/Registermatch.hs b/hledger/Hledger/Cli/Commands/Registermatch.hs
index aa0e83bd5..0465653ed 100755
--- a/hledger/Hledger/Cli/Commands/Registermatch.hs
+++ b/hledger/Hledger/Cli/Commands/Registermatch.hs
@@ -34,7 +34,7 @@ registermatch opts@CliOpts{rawopts_=rawopts,reportspec_=rspec} j =
                                  ,Nothing
                                  ,tdescription <$> ptransaction p
                                  ,p
-                                 ,0)
+                                 ,nullmixedamt)
     _ -> putStrLn "please provide one description argument."
 
 -- Identify the closest recent match for this description in the given date-sorted postings.
diff --git a/hledger/Hledger/Cli/Commands/Roi.hs b/hledger/Hledger/Cli/Commands/Roi.hs
index 6d3812537..b32c3869b 100644
--- a/hledger/Hledger/Cli/Commands/Roi.hs
+++ b/hledger/Hledger/Cli/Commands/Roi.hs
@@ -102,7 +102,7 @@ roi CliOpts{rawopts_=rawopts, reportspec_=rspec@ReportSpec{rsOpts=ReportOpts{..}
     -- Spans are [spanBegin,spanEnd), and spanEnd is 1 day after then actual end date we are interested in
     let
       cashFlowApplyCostValue = map (\(d,amt) -> (d,mixedAmountValue spanEnd d amt))
-      
+
       valueBefore =
         mixedAmountValue spanEnd spanBegin $ 
         total trans (And [ investmentsQuery
@@ -115,7 +115,7 @@ roi CliOpts{rawopts_=rawopts, reportspec_=rspec@ReportSpec{rsOpts=ReportOpts{..}
 
       priceDates = dbg3 "priceDates" $ nub $ filter (spanContainsDate span) priceDirectiveDates
       cashFlow =
-        ((map (\d -> (d,0)) priceDates)++) $
+        ((map (\d -> (d,nullmixedamt)) priceDates)++) $
         cashFlowApplyCostValue $
         calculateCashFlow trans (And [ Not investmentsQuery
                                      , Not pnlQuery
@@ -133,14 +133,14 @@ roi CliOpts{rawopts_=rawopts, reportspec_=rspec@ReportSpec{rsOpts=ReportOpts{..}
 
     irr <- internalRateOfReturn showCashFlow prettyTables thisSpan
     twr <- timeWeightedReturn showCashFlow prettyTables investmentsQuery trans mixedAmountValue thisSpan
-    let cashFlowAmt = negate $ sum $ map snd cashFlow
+    let cashFlowAmt = maNegate . maSum $ map snd cashFlow
     let smallIsZero x = if abs x < 0.01 then 0.0 else x
     return [ showDate spanBegin
            , showDate (addDays (-1) spanEnd)
            , T.pack $ showMixedAmount valueBefore
            , T.pack $ showMixedAmount cashFlowAmt
            , T.pack $ showMixedAmount valueAfter
-           , T.pack $ showMixedAmount (valueAfter - (valueBefore + cashFlowAmt))
+           , T.pack $ showMixedAmount (valueAfter `maMinus` (valueBefore `maPlus` cashFlowAmt))
            , T.pack $ printf "%0.2f%%" $ smallIsZero irr
            , T.pack $ printf "%0.2f%%" $ smallIsZero twr ]
 
@@ -165,12 +165,12 @@ timeWeightedReturn showCashFlow prettyTables investmentsQuery trans mixedAmountV
         -- first for processing cash flow. This is why pnl changes are Left
         -- and cashflows are Right
         sort
-        $ (++) (map (\(date,amt) -> (date,Left (-amt))) pnl )
+        $ (++) (map (\(date,amt) -> (date,Left $ maNegate amt)) pnl )
         -- Aggregate all entries for a single day, assuming that intraday interest is negligible
-        $ map (\date_cash -> let (dates, cash) = unzip date_cash in (head dates, Right (sum cash)))
+        $ map (\date_cash -> let (dates, cash) = unzip date_cash in (head dates, Right (maSum cash)))
         $ groupBy ((==) `on` fst)
         $ sortOn fst
-        $ map (\(d,a) -> (d, negate a))
+        $ map (\(d,a) -> (d, maNegate a))
         $ cashFlow
 
   let units =
@@ -203,17 +203,15 @@ timeWeightedReturn showCashFlow prettyTables investmentsQuery trans mixedAmountV
   when showCashFlow $ do
     printf "\nTWR cash flow for %s - %s\n" (showDate spanBegin) (showDate (addDays (-1) spanEnd))
     let (dates', amounts) = unzip changes
-        cashflows' = map (either (\_ -> 0) id) amounts
-        pnls' = map (either id (\_ -> 0)) amounts
-        (valuesOnDate',unitsBoughtOrSold', unitPrices', unitBalances') = unzip4 units
+        cashflows' = map (either (const nullmixedamt) id) amounts
+        pnls = map (either id (const nullmixedamt)) amounts
+        (valuesOnDate,unitsBoughtOrSold', unitPrices', unitBalances') = unzip4 units
         add x lst = if valueBefore/=0 then x:lst else lst
         dates = add spanBegin dates'
         cashflows = add valueBeforeAmt cashflows'
-        pnls = add 0 pnls'
         unitsBoughtOrSold = add initialUnits unitsBoughtOrSold'
         unitPrices = add initialUnitPrice unitPrices'
         unitBalances = add initialUnits unitBalances'
-        valuesOnDate = add 0 valuesOnDate'
 
     TL.putStr $ Ascii.render prettyTables id id T.pack
       (Table
@@ -236,11 +234,11 @@ timeWeightedReturn showCashFlow prettyTables investmentsQuery trans mixedAmountV
   return annualizedTWR
 
 internalRateOfReturn showCashFlow prettyTables (OneSpan spanBegin spanEnd valueBefore valueAfter cashFlow _pnl) = do
-  let prefix = (spanBegin, negate valueBefore)
+  let prefix = (spanBegin, maNegate valueBefore)
 
       postfix = (spanEnd, valueAfter)
 
-      totalCF = filter ((/=0) . snd) $ prefix : (sortOn fst cashFlow) ++ [postfix]
+      totalCF = filter (maIsNonZero . snd) $ prefix : (sortOn fst cashFlow) ++ [postfix]
 
   when showCashFlow $ do
     printf "\nIRR cash flow for %s - %s\n" (showDate spanBegin) (showDate (addDays (-1) spanEnd))
@@ -267,16 +265,15 @@ type CashFlow = [(Day, MixedAmount)]
 
 interestSum :: Day -> CashFlow -> Double -> Double
 interestSum referenceDay cf rate = sum $ map go cf
-    where go (t,m) = fromRational (toRational (unMix m)) * (rate ** (fromIntegral (referenceDay `diffDays` t) / 365))
+  where go (t,m) = realToFrac (unMix m) * rate ** (fromIntegral (referenceDay `diffDays` t) / 365)
 
 
 calculateCashFlow :: [Transaction] -> Query -> CashFlow
-calculateCashFlow trans query = filter ((/=0).snd) $ map go trans
-    where
-    go t = (transactionDate2 t, total [t] query)
+calculateCashFlow trans query = filter (maIsNonZero . snd) $ map go trans
+  where go t = (transactionDate2 t, total [t] query)
 
 total :: [Transaction] -> Query -> MixedAmount
-total trans query = sumPostings $  filter (matchesPosting query) $ concatMap realPostings trans
+total trans query = sumPostings . filter (matchesPosting query) $ concatMap realPostings trans
 
 unMix :: MixedAmount -> Quantity
 unMix a =

From d6a4310d8fec1241ef3582d9ed220aec511f2e3c Mon Sep 17 00:00:00 2001
From: Stephen Morgan <morgan.stephen99@gmail.com>
Date: Sun, 31 Jan 2021 15:23:46 +1100
Subject: [PATCH 2/2] lib,cli,ui,bin: Eliminate all uses of Mixed outside of
 Hledger.Data.Amount.

Exceptions are for dealing with the pamount field, which is really just
dealing with an unnormalised list of amounts.

This creates an API for dealing with MixedAmount, so we never have to
access the internals outside of Hledger.Data.Amount.

Also remove a comment, since it looks like #1207 has been resolved.
---
 bin/_hledger-chart.hs                         |  2 +-
 bin/hledger-check-fancyassertions.hs          |  8 ++---
 hledger-lib/Hledger/Data/Amount.hs            | 30 ++++++++---------
 hledger-lib/Hledger/Data/Journal.hs           | 32 ++++++++-----------
 hledger-lib/Hledger/Data/Posting.hs           |  3 +-
 hledger-lib/Hledger/Data/Timeclock.hs         |  2 +-
 hledger-lib/Hledger/Data/Transaction.hs       |  2 +-
 .../Hledger/Data/TransactionModifier.hs       |  6 ++--
 hledger-lib/Hledger/Read/Common.hs            |  6 ++--
 hledger-lib/Hledger/Read/CsvReader.hs         |  2 +-
 hledger-lib/Hledger/Read/JournalReader.hs     |  2 +-
 hledger-lib/Hledger/Reports/BalanceReport.hs  | 16 +++++-----
 hledger-lib/Hledger/Reports/BudgetReport.hs   | 10 +++---
 .../Hledger/Reports/MultiBalanceReport.hs     | 26 +++++++--------
 hledger-lib/Hledger/Reports/PostingsReport.hs | 20 ++++++------
 hledger-ui/Hledger/UI/AccountsScreen.hs       |  3 +-
 hledger/Hledger/Cli/Commands/Add.hs           |  6 ++--
 hledger/Hledger/Cli/Commands/Print.hs         |  3 +-
 18 files changed, 85 insertions(+), 94 deletions(-)

diff --git a/bin/_hledger-chart.hs b/bin/_hledger-chart.hs
index c8ced0c8d..f0601c32d 100755
--- a/bin/_hledger-chart.hs
+++ b/bin/_hledger-chart.hs
@@ -162,7 +162,7 @@ sameSignNonZero is
  | otherwise = (map pos $ filter (test.fourth4) nzs, sign)
  where
    nzs = filter ((/=0).fourth4) is
-   pos (acct,_,_,Mixed as) = (acct, abs $ read $ show $ maybe 0 aquantity $ headMay as)
+   pos (acct,_,_,as) = (acct, abs $ read $ show $ maybe 0 aquantity $ headMay $ amounts as)
    sign = if fourth4 (head nzs) >= 0 then 1 else (-1)
    test = if sign > 0 then (>0) else (<0)
 
diff --git a/bin/hledger-check-fancyassertions.hs b/bin/hledger-check-fancyassertions.hs
index d0f111218..2f8ea1baa 100755
--- a/bin/hledger-check-fancyassertions.hs
+++ b/bin/hledger-check-fancyassertions.hs
@@ -223,10 +223,10 @@ checkAssertion accounts = checkAssertion'
 
     -- Add missing amounts (with 0 value), normalise, throw away style
     -- information, and sort by commodity name.
-    fixup (H.Mixed m1) (H.Mixed m2) = H.Mixed $
-      let m = H.Mixed (m1 ++ [m_ { H.aquantity = 0 } | m_ <- m2])
-          (H.Mixed as) = H.normaliseMixedAmount m
-      in sortOn H.acommodity . map (\a -> a { H.astyle = H.amountstyle }) $ as
+    fixup m1 m2 =
+      let m = H.mixed $ amounts m1 ++ [m_ { H.aquantity = 0 } | m_ <- amounts m2]
+          as = amounts $ H.normaliseMixedAmount m
+      in H.mixed $ sortOn H.acommodity . map (\a -> a { H.astyle = H.amountstyle }) $ as
 
 -- | Check if an account name is mentioned in an assertion.
 inAssertion :: H.AccountName -> Predicate -> Bool
diff --git a/hledger-lib/Hledger/Data/Amount.hs b/hledger-lib/Hledger/Data/Amount.hs
index a01330369..2633522b8 100644
--- a/hledger-lib/Hledger/Data/Amount.hs
+++ b/hledger-lib/Hledger/Data/Amount.hs
@@ -530,7 +530,7 @@ nullmixedamt = Mixed []
 
 -- | A temporary value for parsed transactions which had no amount specified.
 missingmixedamt :: MixedAmount
-missingmixedamt = Mixed [missingamt]
+missingmixedamt = mixedAmount missingamt
 
 -- | Convert amounts in various commodities into a normalised MixedAmount.
 mixed :: [Amount] -> MixedAmount
@@ -964,37 +964,37 @@ tests_Amount = tests "Amount" [
         @?= Mixed [usd (-1) @@ eur 2 ]
 
     ,test "showMixedAmount" $ do
-       showMixedAmount (Mixed [usd 1]) @?= "$1.00"
-       showMixedAmount (Mixed [usd 1 `at` eur 2]) @?= "$1.00 @ €2.00"
-       showMixedAmount (Mixed [usd 0]) @?= "0"
-       showMixedAmount (Mixed []) @?= "0"
+       showMixedAmount (mixedAmount (usd 1)) @?= "$1.00"
+       showMixedAmount (mixedAmount (usd 1 `at` eur 2)) @?= "$1.00 @ €2.00"
+       showMixedAmount (mixedAmount (usd 0)) @?= "0"
+       showMixedAmount nullmixedamt @?= "0"
        showMixedAmount missingmixedamt @?= ""
 
     ,test "showMixedAmountWithoutPrice" $ do
       let a = usd 1 `at` eur 2
-      showMixedAmountWithoutPrice False (Mixed [a]) @?= "$1.00"
-      showMixedAmountWithoutPrice False (Mixed [a, -a]) @?= "0"
+      showMixedAmountWithoutPrice False (mixedAmount (a)) @?= "$1.00"
+      showMixedAmountWithoutPrice False (mixed [a, -a]) @?= "0"
 
     ,tests "normaliseMixedAmount" [
        test "a missing amount overrides any other amounts" $
-        normaliseMixedAmount (Mixed [usd 1, missingamt]) @?= missingmixedamt
+        amounts (normaliseMixedAmount $ mixed [usd 1, missingamt]) @?= [missingamt]
       ,test "unpriced same-commodity amounts are combined" $
-        normaliseMixedAmount (Mixed [usd 0, usd 2]) @?= Mixed [usd 2]
+        amounts (normaliseMixedAmount $ mixed [usd 0, usd 2]) @?= [usd 2]
       ,test "amounts with same unit price are combined" $
-        normaliseMixedAmount (Mixed [usd 1 `at` eur 1, usd 1 `at` eur 1]) @?= Mixed [usd 2 `at` eur 1]
+        amounts (normaliseMixedAmount $ mixed [usd 1 `at` eur 1, usd 1 `at` eur 1]) @?= [usd 2 `at` eur 1]
       ,test "amounts with different unit prices are not combined" $
-        normaliseMixedAmount (Mixed [usd 1 `at` eur 1, usd 1 `at` eur 2]) @?= Mixed [usd 1 `at` eur 1, usd 1 `at` eur 2]
+        amounts (normaliseMixedAmount $ mixed [usd 1 `at` eur 1, usd 1 `at` eur 2]) @?= [usd 1 `at` eur 1, usd 1 `at` eur 2]
       ,test "amounts with total prices are combined" $
-        normaliseMixedAmount (Mixed  [usd 1 @@ eur 1, usd 1 @@ eur 1]) @?= Mixed [usd 2 @@ eur 2]
+        amounts (normaliseMixedAmount $ mixed [usd 1 @@ eur 1, usd 1 @@ eur 1]) @?= [usd 2 @@ eur 2]
     ]
 
     ,test "normaliseMixedAmountSquashPricesForDisplay" $ do
-       normaliseMixedAmountSquashPricesForDisplay (Mixed []) @?= Mixed [nullamt]
+       amounts (normaliseMixedAmountSquashPricesForDisplay nullmixedamt) @?= [nullamt]
        assertBool "" $ mixedAmountLooksZero $ normaliseMixedAmountSquashPricesForDisplay
-        (Mixed [usd 10
+        (mixed [usd 10
                ,usd 10 @@ eur 7
                ,usd (-10)
-               ,usd (-10) @@ eur 7
+               ,usd (-10) @@ eur (-7)
                ])
 
   ]
diff --git a/hledger-lib/Hledger/Data/Journal.hs b/hledger-lib/Hledger/Data/Journal.hs
index 867140e42..78f23103a 100644
--- a/hledger-lib/Hledger/Data/Journal.hs
+++ b/hledger-lib/Hledger/Data/Journal.hs
@@ -524,7 +524,7 @@ filterTransactionAmounts q t@Transaction{tpostings=ps} = t{tpostings=map (filter
 
 -- | Filter out all parts of this posting's amount which do not match the query.
 filterPostingAmount :: Query -> Posting -> Posting
-filterPostingAmount q p@Posting{pamount=Mixed as} = p{pamount=Mixed $ filter (q `matchesAmount`) as}
+filterPostingAmount q p@Posting{pamount=as} = p{pamount=filterMixedAmount (q `matchesAmount`) as}
 
 filterTransactionPostings :: Query -> Transaction -> Transaction
 filterTransactionPostings q t@Transaction{tpostings=ps} = t{tpostings=filter (q `matchesPosting`) ps}
@@ -897,21 +897,15 @@ addOrAssignAmountAndCheckAssertionB p@Posting{paccount=acc, pamount=amt, pbalanc
       return p
 
   -- no explicit posting amount, but there is a balance assignment
-  -- TODO this doesn't yet handle inclusive assignments right, #1207
   | Just BalanceAssertion{baamount,batotal,bainclusive} <- mba = do
-      (diff,newbal) <- case batotal of
-        -- a total balance assignment (==, all commodities)
-        True  -> do
-          let newbal = Mixed [baamount]
-          diff <- (if bainclusive then setInclusiveRunningBalanceB else setRunningBalanceB) acc newbal
-          return (diff,newbal)
-        -- a partial balance assignment (=, one commodity)
-        False -> do
-          oldbalothercommodities <- filterMixedAmount ((acommodity baamount /=) . acommodity) <$> getRunningBalanceB acc
-          let assignedbalthiscommodity = Mixed [baamount]
-              newbal = maPlus oldbalothercommodities assignedbalthiscommodity
-          diff <- (if bainclusive then setInclusiveRunningBalanceB else setRunningBalanceB) acc newbal
-          return (diff,newbal)
+      newbal <- if batotal
+                   -- a total balance assignment (==, all commodities)
+                   then return $ mixedAmount baamount
+                   -- a partial balance assignment (=, one commodity)
+                   else do
+                     oldbalothercommodities <- filterMixedAmount ((acommodity baamount /=) . acommodity) <$> getRunningBalanceB acc
+                     return $ maAddAmount oldbalothercommodities baamount
+      diff <- (if bainclusive then setInclusiveRunningBalanceB else setRunningBalanceB) acc newbal
       let p' = p{pamount=diff, poriginal=Just $ originalPosting p}
       whenM (R.reader bsAssrt) $ checkBalanceAssertionB p' newbal
       return p'
@@ -1153,7 +1147,7 @@ canonicalStyle a b = a{asprecision=prec, asdecimalpoint=decmark, asdigitgroups=m
 --       fixtransaction t@Transaction{tdate=d, tpostings=ps} = t{tpostings=map fixposting ps}
 --        where
 --         fixposting p@Posting{pamount=a} = p{pamount=fixmixedamount a}
---         fixmixedamount (Mixed as) = Mixed $ map fixamount as
+--         fixmixedamount = mapMixedAmount fixamount
 --         fixamount = fixprice
 --         fixprice a@Amount{price=Just _} = a
 --         fixprice a@Amount{commodity=c} = a{price=maybe Nothing (Just . UnitPrice) $ journalPriceDirectiveFor j d c}
@@ -1182,8 +1176,8 @@ journalInferMarketPricesFromTransactions j =
 postingInferredmarketPrice :: Posting -> Maybe MarketPrice
 postingInferredmarketPrice p@Posting{pamount} =
   -- convert any total prices to unit prices
-  case mixedAmountTotalPriceToUnitPrice pamount of
-    Mixed ( Amount{acommodity=fromcomm, aprice = Just (UnitPrice Amount{acommodity=tocomm, aquantity=rate})} : _) ->
+  case amounts $ mixedAmountTotalPriceToUnitPrice pamount of
+    Amount{acommodity=fromcomm, aprice = Just (UnitPrice Amount{acommodity=tocomm, aquantity=rate})}:_ ->
       Just MarketPrice {
          mpdate = postingDate p
         ,mpfrom = fromcomm
@@ -1561,7 +1555,7 @@ tests_Journal = tests "Journal" [
             ]}
       assertRight ej
       let Right j = ej
-      (jtxns j & head & tpostings & head & pamount) @?= Mixed [num 1]
+      (jtxns j & head & tpostings & head & pamount) @?= mixedAmount (num 1)
 
     ,test "same-day-1" $ do
       assertRight $ journalBalanceTransactions True $
diff --git a/hledger-lib/Hledger/Data/Posting.hs b/hledger-lib/Hledger/Data/Posting.hs
index 866fb6698..c06bbbf16 100644
--- a/hledger-lib/Hledger/Data/Posting.hs
+++ b/hledger-lib/Hledger/Data/Posting.hs
@@ -202,8 +202,7 @@ sumPostings = foldl' (\amt p -> maPlus amt $ pamount p) nullmixedamt
 
 -- | Remove all prices of a posting
 removePrices :: Posting -> Posting
-removePrices p = p{ pamount = Mixed $ remove <$> amounts (pamount p) }
-  where remove a = a { aprice = Nothing }
+removePrices = postingTransformAmount (mapMixedAmount $ \a -> a{aprice=Nothing})
 
 -- | Get a posting's (primary) date - it's own primary date if specified,
 -- otherwise the parent transaction's primary date, or the null date if
diff --git a/hledger-lib/Hledger/Data/Timeclock.hs b/hledger-lib/Hledger/Data/Timeclock.hs
index 2d5f1fea2..8e121d6f7 100644
--- a/hledger-lib/Hledger/Data/Timeclock.hs
+++ b/hledger-lib/Hledger/Data/Timeclock.hs
@@ -121,7 +121,7 @@ entryFromTimeclockInOut i o
       showtime = take 5 . show
       hours    = elapsedSeconds (toutc otime) (toutc itime) / 3600 where toutc = localTimeToUTC utc
       acctname = tlaccount i
-      amount   = Mixed [hrs hours]
+      amount   = mixedAmount $ hrs hours
       ps       = [posting{paccount=acctname, pamount=amount, ptype=VirtualPosting, ptransaction=Just t}]
 
 
diff --git a/hledger-lib/Hledger/Data/Transaction.hs b/hledger-lib/Hledger/Data/Transaction.hs
index 290344741..45c0c8f7a 100644
--- a/hledger-lib/Hledger/Data/Transaction.hs
+++ b/hledger-lib/Hledger/Data/Transaction.hs
@@ -551,7 +551,7 @@ priceInferrerFor t pt = inferprice
 
     inferprice p@Posting{pamount=Mixed [a]}
       | caninferprices && ptype p == pt && acommodity a == fromcommodity
-        = p{pamount=Mixed [a{aprice=Just conversionprice}], poriginal=Just $ originalPosting p}
+        = p{pamount=mixedAmount $ a{aprice=Just conversionprice}, poriginal=Just $ originalPosting p}
       where
         fromcommodity = head $ filter (`elem` sumcommodities) pcommodities -- these heads are ugly but should be safe
         totalpricesign = if aquantity a < 0 then negate else id
diff --git a/hledger-lib/Hledger/Data/TransactionModifier.hs b/hledger-lib/Hledger/Data/TransactionModifier.hs
index 3a09b03a3..2a493a4a1 100644
--- a/hledger-lib/Hledger/Data/TransactionModifier.hs
+++ b/hledger-lib/Hledger/Data/TransactionModifier.hs
@@ -120,14 +120,14 @@ tmPostingRuleToFunction querytxt pr =
             -- Approach 1: convert to a unit price and increase the display precision slightly
             -- Mixed as = dbg6 "multipliedamount" $ n `multiplyMixedAmount` mixedAmountTotalPriceToUnitPrice matchedamount
             -- Approach 2: multiply the total price (keeping it positive) as well as the quantity
-            Mixed as = dbg6 "multipliedamount" $ n `multiplyMixedAmount` matchedamount
+            as = dbg6 "multipliedamount" $ n `multiplyMixedAmount` matchedamount
           in
             case acommodity pramount of
-              "" -> Mixed as
+              "" -> as
               -- TODO multipliers with commodity symbols are not yet a documented feature.
               -- For now: in addition to multiplying the quantity, it also replaces the
               -- matched amount's commodity, display style, and price with those of the posting rule.
-              c  -> Mixed [a{acommodity = c, astyle = astyle pramount, aprice = aprice pramount} | a <- as]
+              c  -> mapMixedAmount (\a -> a{acommodity = c, astyle = astyle pramount, aprice = aprice pramount}) as
 
 postingRuleMultiplier :: TMPostingRule -> Maybe Quantity
 postingRuleMultiplier p =
diff --git a/hledger-lib/Hledger/Read/Common.hs b/hledger-lib/Hledger/Read/Common.hs
index 3d6731493..fee9e7824 100644
--- a/hledger-lib/Hledger/Read/Common.hs
+++ b/hledger-lib/Hledger/Read/Common.hs
@@ -729,7 +729,7 @@ spaceandamountormissingp :: JournalParser m MixedAmount
 spaceandamountormissingp =
   option missingmixedamt $ try $ do
     lift $ skipNonNewlineSpaces1
-    Mixed . (:[]) <$> amountp
+    mixedAmount <$> amountp
 
 -- | Parse a single-commodity amount, with optional symbol on the left
 -- or right, followed by, in any order: an optional transaction price,
@@ -855,7 +855,7 @@ amountp' s =
 
 -- | Parse a mixed amount from a string, or get an error.
 mamountp' :: String -> MixedAmount
-mamountp' = Mixed . (:[]) . amountp'
+mamountp' = mixedAmount . amountp'
 
 -- | Parse a minus or plus sign followed by zero or more spaces,
 -- or nothing, returning a function that negates or does nothing.
@@ -1560,7 +1560,7 @@ tests_Common = tests "Common" [
      assertParseError p "1.5555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555555" ""
 
   ,tests "spaceandamountormissingp" [
-     test "space and amount" $ assertParseEq spaceandamountormissingp " $47.18" (Mixed [usd 47.18])
+     test "space and amount" $ assertParseEq spaceandamountormissingp " $47.18" (mixedAmount $ usd 47.18)
     ,test "empty string" $ assertParseEq spaceandamountormissingp "" missingmixedamt
     -- ,test "just space" $ assertParseEq spaceandamountormissingp " " missingmixedamt  -- XXX should it ?
     -- ,test "just amount" $ assertParseError spaceandamountormissingp "$47.18" ""  -- succeeds, consuming nothing
diff --git a/hledger-lib/Hledger/Read/CsvReader.hs b/hledger-lib/Hledger/Read/CsvReader.hs
index 2a9fdbb7c..d5f224bc9 100644
--- a/hledger-lib/Hledger/Read/CsvReader.hs
+++ b/hledger-lib/Hledger/Read/CsvReader.hs
@@ -1048,7 +1048,7 @@ getBalance rules record currency n = do
 -- The whole CSV record is provided for the error message.
 parseAmount :: CsvRules -> CsvRecord -> Text -> Text -> MixedAmount
 parseAmount rules record currency s =
-    either mkerror (Mixed . (:[])) $  -- PARTIAL:
+    either mkerror mixedAmount $  -- PARTIAL:
     runParser (evalStateT (amountp <* eof) journalparsestate) "" $
     currency <> simplifySign s
   where
diff --git a/hledger-lib/Hledger/Read/JournalReader.hs b/hledger-lib/Hledger/Read/JournalReader.hs
index 027df37d7..1b5810ccb 100644
--- a/hledger-lib/Hledger/Read/JournalReader.hs
+++ b/hledger-lib/Hledger/Read/JournalReader.hs
@@ -711,7 +711,7 @@ postingp mTransactionYear = do
     return (status, account)
   let (ptype, account') = (accountNamePostingType account, textUnbracket account)
   lift skipNonNewlineSpaces
-  amount <- option missingmixedamt $ Mixed . (:[]) <$> amountp
+  amount <- option missingmixedamt $ mixedAmount <$> amountp
   lift skipNonNewlineSpaces
   massertion <- optional balanceassertionp
   lift skipNonNewlineSpaces
diff --git a/hledger-lib/Hledger/Reports/BalanceReport.hs b/hledger-lib/Hledger/Reports/BalanceReport.hs
index 71ba82802..6cf73520b 100644
--- a/hledger-lib/Hledger/Reports/BalanceReport.hs
+++ b/hledger-lib/Hledger/Reports/BalanceReport.hs
@@ -125,7 +125,7 @@ tests_BalanceReport = tests "BalanceReport" [
        ,("income:gifts","income:gifts",0, mamountp' "$-1.00")
        ,("income:salary","income:salary",0, mamountp' "$-1.00")
        ],
-       Mixed [usd 0])
+       mixedAmount (usd 0))
 
     ,test "with --tree" $
      (defreportspec{rsOpts=defreportopts{accountlistmode_=ALTree}}, samplejournal) `gives`
@@ -142,7 +142,7 @@ tests_BalanceReport = tests "BalanceReport" [
        ,("income:gifts","gifts",1, mamountp' "$-1.00")
        ,("income:salary","salary",1, mamountp' "$-1.00")
        ],
-       Mixed [usd 0])
+       mixedAmount (usd 0))
 
     ,test "with --depth=N" $
      (defreportspec{rsOpts=defreportopts{depth_=Just 1}}, samplejournal) `gives`
@@ -150,7 +150,7 @@ tests_BalanceReport = tests "BalanceReport" [
        ("expenses",    "expenses",    0, mamountp'  "$2.00")
        ,("income",      "income",      0, mamountp' "$-2.00")
        ],
-       Mixed [usd 0])
+       mixedAmount (usd 0))
 
     ,test "with depth:N" $
      (defreportspec{rsQuery=Depth 1}, samplejournal) `gives`
@@ -158,7 +158,7 @@ tests_BalanceReport = tests "BalanceReport" [
        ("expenses",    "expenses",    0, mamountp'  "$2.00")
        ,("income",      "income",      0, mamountp' "$-2.00")
        ],
-       Mixed [usd 0])
+       mixedAmount (usd 0))
 
     ,test "with date:" $
      (defreportspec{rsQuery=Date $ DateSpan (Just $ fromGregorian 2009 01 01) (Just $ fromGregorian 2010 01 01)}, samplejournal2) `gives`
@@ -170,7 +170,7 @@ tests_BalanceReport = tests "BalanceReport" [
         ("assets:bank:checking","assets:bank:checking",0,mamountp' "$1.00")
        ,("income:salary","income:salary",0,mamountp' "$-1.00")
        ],
-       Mixed [usd 0])
+       mixedAmount (usd 0))
 
     ,test "with desc:" $
      (defreportspec{rsQuery=Desc $ toRegexCI' "income"}, samplejournal) `gives`
@@ -178,7 +178,7 @@ tests_BalanceReport = tests "BalanceReport" [
         ("assets:bank:checking","assets:bank:checking",0,mamountp' "$1.00")
        ,("income:salary","income:salary",0, mamountp' "$-1.00")
        ],
-       Mixed [usd 0])
+       mixedAmount (usd 0))
 
     ,test "with not:desc:" $
      (defreportspec{rsQuery=Not . Desc $ toRegexCI' "income"}, samplejournal) `gives`
@@ -189,7 +189,7 @@ tests_BalanceReport = tests "BalanceReport" [
        ,("expenses:supplies","expenses:supplies",0, mamountp' "$1.00")
        ,("income:gifts","income:gifts",0, mamountp' "$-1.00")
        ],
-       Mixed [usd 0])
+       mixedAmount (usd 0))
 
     ,test "with period on a populated period" $
       (defreportspec{rsOpts=defreportopts{period_= PeriodBetween (fromGregorian 2008 1 1) (fromGregorian 2008 1 2)}}, samplejournal) `gives`
@@ -198,7 +198,7 @@ tests_BalanceReport = tests "BalanceReport" [
          ("assets:bank:checking","assets:bank:checking",0, mamountp' "$1.00")
         ,("income:salary","income:salary",0, mamountp' "$-1.00")
         ],
-        Mixed [usd 0])
+        mixedAmount (usd 0))
 
      ,test "with period on an unpopulated period" $
       (defreportspec{rsOpts=defreportopts{period_= PeriodBetween (fromGregorian 2008 1 2) (fromGregorian 2008 1 3)}}, samplejournal) `gives`
diff --git a/hledger-lib/Hledger/Reports/BudgetReport.hs b/hledger-lib/Hledger/Reports/BudgetReport.hs
index eab7b8ab7..26aa97e82 100644
--- a/hledger-lib/Hledger/Reports/BudgetReport.hs
+++ b/hledger-lib/Hledger/Reports/BudgetReport.hs
@@ -280,15 +280,15 @@ budgetReportAsText ropts@ReportOpts{..} budgetr = TB.toLazyText $
     -- - the goal is zero
     percentage :: Change -> BudgetGoal -> Maybe Percentage
     percentage actual budget =
-      case (maybecost $ normaliseMixedAmount actual, maybecost $ normaliseMixedAmount budget) of
-        (Mixed [a], Mixed [b]) | (acommodity a == acommodity b || amountLooksZero a) && not (amountLooksZero b)
+      case (costedAmounts actual, costedAmounts budget) of
+        ([a], [b]) | (acommodity a == acommodity b || amountLooksZero a) && not (amountLooksZero b)
             -> Just $ 100 * aquantity a / aquantity b
         _   -> -- trace (pshow $ (maybecost actual, maybecost budget))  -- debug missing percentage
                Nothing
       where
-        maybecost = case cost_ of
-            Cost   -> mixedAmountCost
-            NoCost -> id
+        costedAmounts = case cost_ of
+            Cost   -> amounts . mixedAmountCost . normaliseMixedAmount
+            NoCost -> amounts . normaliseMixedAmount
 
     maybetranspose | transpose_ = \(Table rh ch vals) -> Table ch rh (transpose vals)
                    | otherwise  = id
diff --git a/hledger-lib/Hledger/Reports/MultiBalanceReport.hs b/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
index bcf72b866..5c7ed4a51 100644
--- a/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
+++ b/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
@@ -591,8 +591,8 @@ tests_MultiBalanceReport = tests "MultiBalanceReport" [
      ,test "with -H on a populated period"  $
       (defreportspec{rsOpts=defreportopts{period_= PeriodBetween (fromGregorian 2008 1 1) (fromGregorian 2008 1 2), balancetype_=HistoricalBalance}}, samplejournal) `gives`
        (
-        [ PeriodicReportRow (flatDisplayName "assets:bank:checking") [mamountp' "$1.00"]  (mamountp' "$1.00")  (Mixed [amt0 {aquantity=1}])
-        , PeriodicReportRow (flatDisplayName "income:salary")        [mamountp' "$-1.00"] (mamountp' "$-1.00") (Mixed [amt0 {aquantity=(-1)}])
+        [ PeriodicReportRow (flatDisplayName "assets:bank:checking") [mamountp' "$1.00"]  (mamountp' "$1.00")  (mixedAmount amt0{aquantity=1})
+        , PeriodicReportRow (flatDisplayName "income:salary")        [mamountp' "$-1.00"] (mamountp' "$-1.00") (mixedAmount amt0{aquantity=(-1)})
         ],
         mamountp' "$0.00")
 
@@ -600,23 +600,23 @@ tests_MultiBalanceReport = tests "MultiBalanceReport" [
      --  (defreportopts{period_= PeriodBetween (fromGregorian 2008 1 2) (fromGregorian 2008 1 3), balancetype_=HistoricalBalance}, samplejournal) `gives`
      --   (
      --    [
-     --     ("assets:bank:checking","checking",3, [mamountp' "$1.00"], mamountp' "$1.00",Mixed [amt0 {aquantity=1}])
-     --    ,("income:salary","salary",2, [mamountp' "$-1.00"], mamountp' "$-1.00",Mixed [amt0 {aquantity=(-1)}])
+     --     ("assets:bank:checking","checking",3, [mamountp' "$1.00"], mamountp' "$1.00",mixedAmount amt0 {aquantity=1})
+     --    ,("income:salary","salary",2, [mamountp' "$-1.00"], mamountp' "$-1.00",mixedAmount amt0 {aquantity=(-1)})
      --    ],
-     --    Mixed [usd0])
+     --    mixedAmount usd0)
 
      -- ,test "a valid history on an empty period (more complex)"  $
      --  (defreportopts{period_= PeriodBetween (fromGregorian 2009 1 1) (fromGregorian 2009 1 2), balancetype_=HistoricalBalance}, samplejournal) `gives`
      --   (
      --    [
-     --    ("assets:bank:checking","checking",3, [mamountp' "$1.00"], mamountp' "$1.00",Mixed [amt0 {aquantity=1}])
-     --    ,("assets:bank:saving","saving",3, [mamountp' "$1.00"], mamountp' "$1.00",Mixed [amt0 {aquantity=1}])
-     --    ,("assets:cash","cash",2, [mamountp' "$-2.00"], mamountp' "$-2.00",Mixed [amt0 {aquantity=(-2)}])
-     --    ,("expenses:food","food",2, [mamountp' "$1.00"], mamountp' "$1.00",Mixed [amt0 {aquantity=(1)}])
-     --    ,("expenses:supplies","supplies",2, [mamountp' "$1.00"], mamountp' "$1.00",Mixed [amt0 {aquantity=(1)}])
-     --    ,("income:gifts","gifts",2, [mamountp' "$-1.00"], mamountp' "$-1.00",Mixed [amt0 {aquantity=(-1)}])
-     --    ,("income:salary","salary",2, [mamountp' "$-1.00"], mamountp' "$-1.00",Mixed [amt0 {aquantity=(-1)}])
+     --    ("assets:bank:checking","checking",3, [mamountp' "$1.00"], mamountp' "$1.00",mixedAmount amt0 {aquantity=1})
+     --    ,("assets:bank:saving","saving",3, [mamountp' "$1.00"], mamountp' "$1.00",mixedAmount amt0 {aquantity=1})
+     --    ,("assets:cash","cash",2, [mamountp' "$-2.00"], mamountp' "$-2.00",mixedAmount amt0 {aquantity=(-2)})
+     --    ,("expenses:food","food",2, [mamountp' "$1.00"], mamountp' "$1.00",mixedAmount amt0 {aquantity=(1)})
+     --    ,("expenses:supplies","supplies",2, [mamountp' "$1.00"], mamountp' "$1.00",mixedAmount amt0 {aquantity=(1)})
+     --    ,("income:gifts","gifts",2, [mamountp' "$-1.00"], mamountp' "$-1.00",mixedAmount amt0 {aquantity=(-1)})
+     --    ,("income:salary","salary",2, [mamountp' "$-1.00"], mamountp' "$-1.00",mixedAmount amt0 {aquantity=(-1)})
      --    ],
-     --    Mixed [usd0])
+     --    mixedAmount usd0)
     ]
  ]
diff --git a/hledger-lib/Hledger/Reports/PostingsReport.hs b/hledger-lib/Hledger/Reports/PostingsReport.hs
index 4346dff32..a51db0f7b 100644
--- a/hledger-lib/Hledger/Reports/PostingsReport.hs
+++ b/hledger-lib/Hledger/Reports/PostingsReport.hs
@@ -406,10 +406,10 @@ tests_PostingsReport = tests "PostingsReport" [
     --           (summarisePostingsInDateSpan (DateSpan b e) depth showempty ps `is`)
     --   let ps =
     --           [
-    --            nullposting{lpdescription="desc",lpaccount="expenses:food:groceries",lpamount=Mixed [usd 1]}
-    --           ,nullposting{lpdescription="desc",lpaccount="expenses:food:dining",   lpamount=Mixed [usd 2]}
-    --           ,nullposting{lpdescription="desc",lpaccount="expenses:food",          lpamount=Mixed [usd 4]}
-    --           ,nullposting{lpdescription="desc",lpaccount="expenses:food:dining",   lpamount=Mixed [usd 8]}
+    --            nullposting{lpdescription="desc",lpaccount="expenses:food:groceries",lpamount=mixedAmount (usd 1)}
+    --           ,nullposting{lpdescription="desc",lpaccount="expenses:food:dining",   lpamount=mixedAmount (usd 2)}
+    --           ,nullposting{lpdescription="desc",lpaccount="expenses:food",          lpamount=mixedAmount (usd 4)}
+    --           ,nullposting{lpdescription="desc",lpaccount="expenses:food:dining",   lpamount=mixedAmount (usd 8)}
     --           ]
     --   ("2008/01/01","2009/01/01",0,9999,False,[]) `gives`
     --    []
@@ -419,21 +419,21 @@ tests_PostingsReport = tests "PostingsReport" [
     --    ]
     --   ("2008/01/01","2009/01/01",0,9999,False,ts) `gives`
     --    [
-    --     nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses:food",          lpamount=Mixed [usd 4]}
-    --    ,nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses:food:dining",   lpamount=Mixed [usd 10]}
-    --    ,nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses:food:groceries",lpamount=Mixed [usd 1]}
+    --     nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses:food",          lpamount=mixedAmount (usd 4)}
+    --    ,nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses:food:dining",   lpamount=mixedAmount (usd 10)}
+    --    ,nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses:food:groceries",lpamount=mixedAmount (usd 1)}
     --    ]
     --   ("2008/01/01","2009/01/01",0,2,False,ts) `gives`
     --    [
-    --     nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses:food",lpamount=Mixed [usd 15]}
+    --     nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses:food",lpamount=mixedAmount (usd 15)}
     --    ]
     --   ("2008/01/01","2009/01/01",0,1,False,ts) `gives`
     --    [
-    --     nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses",lpamount=Mixed [usd 15]}
+    --     nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="expenses",lpamount=mixedAmount (usd 15)}
     --    ]
     --   ("2008/01/01","2009/01/01",0,0,False,ts) `gives`
     --    [
-    --     nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="",lpamount=Mixed [usd 15]}
+    --     nullposting{lpdate=fromGregorian 2008 01 01,lpdescription="- 2008/12/31",lpaccount="",lpamount=mixedAmount (usd 15)}
     --    ]
 
  ]
diff --git a/hledger-ui/Hledger/UI/AccountsScreen.hs b/hledger-ui/Hledger/UI/AccountsScreen.hs
index d1b958eea..122673d48 100644
--- a/hledger-ui/Hledger/UI/AccountsScreen.hs
+++ b/hledger-ui/Hledger/UI/AccountsScreen.hs
@@ -103,8 +103,7 @@ asInit d reset ui@UIState{
                         ,asItemRenderedAmounts    = map showAmountWithoutPrice amts
                         }
       where
-        Mixed amts = normaliseMixedAmountSquashPricesForDisplay $ stripPrices bal
-        stripPrices (Mixed as) = Mixed $ map stripprice as where stripprice a = a{aprice=Nothing}
+        amts = amounts . normaliseMixedAmountSquashPricesForDisplay $ mixedAmountStripPrices bal
     displayitems = map displayitem items
     -- blanks added for scrolling control, cf RegisterScreen.
     -- XXX Ugly. Changing to 0 helps when debugging.
diff --git a/hledger/Hledger/Cli/Commands/Add.hs b/hledger/Hledger/Cli/Commands/Add.hs
index 5b9802e56..20a9c5f17 100644
--- a/hledger/Hledger/Cli/Commands/Add.hs
+++ b/hledger/Hledger/Cli/Commands/Add.hs
@@ -329,7 +329,7 @@ amountAndCommentWizard PrevInput{..} EntryState{..} = do
       (mhistoricalp,followedhistoricalsofar) =
           case esSimilarTransaction of
             Nothing                        -> (Nothing,False)
-            Just Transaction{tpostings=ps} -> 
+            Just Transaction{tpostings=ps} ->
               ( if length ps >= pnum then Just (ps !! (pnum-1)) else Nothing
               , all sameamount $ zip esPostings ps
               )
@@ -343,7 +343,7 @@ amountAndCommentWizard PrevInput{..} EntryState{..} = do
   retryMsg "A valid hledger amount is required. Eg: 1, $2, 3 EUR, \"4 red apples\"." $
    parser parseAmountAndComment $
    withCompletion (amountCompleter def) $
-   defaultTo' def $ 
+   defaultTo' def $
    nonEmpty $
    linePrewritten (green $ printf "Amount  %d%s: " pnum (showDefault def)) (fromMaybe "" $ prevAmountAndCmnt `atMay` length esPostings) ""
     where
@@ -361,7 +361,7 @@ amountAndCommentWizard PrevInput{..} EntryState{..} = do
         -- eof
         return (a,c)
       balancingamt = maNegate . sumPostings $ filter isReal esPostings
-      balancingamtfirstcommodity = Mixed . take 1 $ amounts balancingamt
+      balancingamtfirstcommodity = mixed . take 1 $ amounts balancingamt
       showamt =
         showMixedAmount . mixedAmountSetPrecision
                   -- what should this be ?
diff --git a/hledger/Hledger/Cli/Commands/Print.hs b/hledger/Hledger/Cli/Commands/Print.hs
index 58248b293..78c8319e2 100644
--- a/hledger/Hledger/Cli/Commands/Print.hs
+++ b/hledger/Hledger/Cli/Commands/Print.hs
@@ -181,9 +181,8 @@ postingToCSV p =
     let credit = if q < 0 then showamt $ negate a_ else "" in
     let debit  = if q >= 0 then showamt a_ else "" in
     [account, amount, c, credit, debit, status, comment])
-   amounts
+   . amounts $ pamount p
   where
-    Mixed amounts = pamount p
     status = T.pack . show $ pstatus p
     account = showAccountName Nothing (ptype p) (paccount p)
     comment = T.strip $ pcomment p