balance: show multi-commodity amts on one line (fixes #186)

To avoid totally breaking the layout of multicolumn balance reports when
there are multi-commodity balances, these are now rendered on a single
line, comma separated. Simple balance reports still use the old vertical
format for now.

hledger-lib/Hledger/Data/Amount.hs

@@ -63,6 +63,7 @@ module Hledger.Data.Amount (
   showAmount,
   showAmountDebug,
   showAmountWithoutPrice,
+  showMixedAmountOneLineWithoutPrice,
   maxprecision,
   maxprecisionwithpoint,
   setAmountPrecision,
@@ -501,6 +502,14 @@ showMixedAmountWithoutPrice m = concat $ intersperse "\n" $ map showfixedwidth a
       width = maximum $ map (length . showAmount) as
       showfixedwidth = printf (printf "%%%ds" width) . showAmountWithoutPrice
 
+-- | Get the one-line string representation of a mixed amount, but without
+-- any \@ prices.
+showMixedAmountOneLineWithoutPrice :: MixedAmount -> String
+showMixedAmountOneLineWithoutPrice m = concat $ intersperse ", " $ map showAmountWithoutPrice as
+    where
+      (Mixed as) = normaliseMixedAmountPreservingFirstPrice $ stripPrices m
+      stripPrices (Mixed as) = Mixed $ map stripprice as where stripprice a = a{aprice=NoPrice}
+
 -- | Canonicalise a mixed amount's display styles using the provided commodity style map.
 canonicaliseMixedAmount :: M.Map Commodity AmountStyle -> MixedAmount -> MixedAmount
 canonicaliseMixedAmount styles (Mixed as) = Mixed $ map (canonicaliseAmount styles) as

hledger/Hledger/Cli/Balance.hs

@@ -374,7 +374,7 @@ periodBalanceReportAsText opts (MultiBalanceReport (colspans, items, coltotals))
    render
     id
     ((" "++) . showDateSpan)
-    showMixedAmountWithoutPrice
+    showMixedAmountOneLineWithoutPrice
     $ Table
       (T.Group NoLine $ map (Header . padright acctswidth) accts)
       (T.Group NoLine $ map Header colspans)
@@ -398,7 +398,7 @@ cumulativeBalanceReportAsText :: ReportOpts -> MultiBalanceReport -> [String]
 cumulativeBalanceReportAsText opts (MultiBalanceReport (colspans, items, coltotals)) =
   (["Ending balance (cumulative):"] ++) $
   trimborder $ lines $
-   render id ((" "++) . maybe "" (showDate . prevday) . spanEnd) showMixedAmountWithoutPrice $
+   render id ((" "++) . maybe "" (showDate . prevday) . spanEnd) showMixedAmountOneLineWithoutPrice $
     addtotalrow $ 
      Table
        (T.Group NoLine $ map (Header . padright acctswidth) accts)
@@ -419,7 +419,7 @@ historicalBalanceReportAsText :: ReportOpts -> MultiBalanceReport -> [String]
 historicalBalanceReportAsText opts (MultiBalanceReport (colspans, items, coltotals)) =
   (["Ending balance (historical):"] ++) $
   trimborder $ lines $
-   render id ((" "++) . maybe "" (showDate . prevday) . spanEnd) showMixedAmountWithoutPrice $
+   render id ((" "++) . maybe "" (showDate . prevday) . spanEnd) showMixedAmountOneLineWithoutPrice $
     addtotalrow $ 
      Table
        (T.Group NoLine $ map (Header . padright acctswidth) accts)