From a72c4f285b9c0f368b7be7dcf37c00812d80adb3 Mon Sep 17 00:00:00 2001
From: Stephen Morgan <morgan.stephen99@gmail.com>
Date: Fri, 12 Jun 2020 11:33:51 +1000
Subject: [PATCH] lib: multiBalanceReport: Break calculateColumns into a
 separate function.

---
 .../Hledger/Reports/MultiBalanceReport.hs     | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/hledger-lib/Hledger/Reports/MultiBalanceReport.hs b/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
index 888d86c62..7e6576739 100644
--- a/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
+++ b/hledger-lib/Hledger/Reports/MultiBalanceReport.hs
@@ -24,6 +24,7 @@ where
 
 import Data.List
 import Data.List.Extra (nubSort)
+import Data.Map (Map)
 import qualified Data.Map as M
 import Data.Maybe
 import Data.Ord
@@ -138,14 +139,8 @@ multiBalanceReportWith ropts@ReportOpts{..} q j priceoracle =
       -- The date spans to be included as report columns.
       colspans = dbg "colspans" $ calculateColSpans ropts reportspan days
 
-      -- Group postings into their columns, with the column end dates.
-      colps :: [([Posting], Maybe Day)] =
-          dbg'' "colps"
-          [ (posts, end) | (DateSpan _ end, posts) <- M.toList colMap ]
-        where
-          colMap = foldr addPosting emptyMap ps
-          addPosting (p, d) = maybe id (M.adjust (p:)) $ latestSpanContaining colspans d
-          emptyMap = M.fromList . zip colspans $ repeat []
+      -- Group postings into their columns.
+      colps = dbg'' "colps" $ calculateColumns colspans ps
 
       ----------------------------------------------------------------------
       -- 4. Calculate account balance changes in each column.
@@ -161,7 +156,7 @@ multiBalanceReportWith ropts@ReportOpts{..} q j priceoracle =
                 | tree_ ropts = filter ((depthq `matchesAccount`).aname) -- exclude deeper balances
                 | otherwise   = clipAccountsAndAggregate depth -- aggregate deeper balances at the depth limit
       colacctchanges :: [[(ClippedAccountName, MixedAmount)]] =
-          dbg'' "colacctchanges" $ map (acctChangesFromPostings . fst) colps
+          dbg'' "colacctchanges" $ map (acctChangesFromPostings . snd) $ M.toList colps
 
       ----------------------------------------------------------------------
       -- 5. Gather the account balance changes into a regular matrix including the accounts
@@ -384,6 +379,13 @@ calculateColSpans ropts reportspan days =
       | otherwise = dbg "displayspan" $ reportspan `spanIntersect` matchedspan  -- exclude leading/trailing empty intervals
     matchedspan = dbg "matchedspan" $ daysSpan days
 
+-- | Group postings into their columns.
+calculateColumns :: [DateSpan] -> [(Posting, Day)] -> Map DateSpan [Posting]
+calculateColumns colspans = foldr addPosting emptyMap
+  where
+    addPosting (p, d) = maybe id (M.adjust (p:)) $ latestSpanContaining colspans d
+    emptyMap = M.fromList . zip colspans $ repeat []
+
 
 -- | Generates a simple non-columnar BalanceReport, but using multiBalanceReport,
 -- in order to support --historical. Does not support tree-mode boring parent eliding.