balance: make -H work with single-column reports #392

-H/--historical now makes a single-column balance report with a start
date show historical balances reflecting earlier postings.  This is
equivalent to specifying no start date, but it's more consistent.

hledger-lib/Hledger/Reports/MultiBalanceReports.hs

@@ -9,7 +9,8 @@ module Hledger.Reports.MultiBalanceReports (
   MultiBalanceReport(..),
   MultiBalanceReportRow,
   multiBalanceReport,
-  multiBalanceReportValue
+  multiBalanceReportValue,
+  singleBalanceReport
 
   -- -- * Tests
   -- tests_Hledger_Reports_MultiBalanceReport
@@ -71,6 +72,20 @@ instance Show MultiBalanceReport where
 -- type alias just to remind us which AccountNames might be depth-clipped, below.
 type ClippedAccountName = AccountName
 
+-- | Generates a single column BalanceReport like balanceReport, but uses
+-- multiBalanceReport, so supports --historical. Does not support
+-- boring parent eliding yet.
+singleBalanceReport :: ReportOpts -> Query -> Journal -> BalanceReport
+singleBalanceReport opts q j = (rows', total)
+  where
+    MultiBalanceReport (_, rows, (totals, _, _)) = multiBalanceReport opts q j
+    rows' = [(a
+             ,if tree_ opts then a' else a   -- BalanceReport expects full account name here with --flat
+             ,if tree_ opts then d-1 else 0  -- BalanceReport uses 0-based account depths
+             , headDef nullmixedamt amts     -- 0 columns is illegal, should not happen, return zeroes if it does
+             ) | (a,a',d, amts, _, _) <- rows]
+    total = headDef nullmixedamt totals
+
 -- | Generate a multicolumn balance report for the matched accounts,
 -- showing the change of balance, accumulated balance, or historical balance
 -- in each of the specified periods.

hledger/Hledger/Cli/Balance.hs

@@ -272,8 +272,8 @@ balancemode = (defCommandMode $ ["balance"] ++ aliases) { -- also accept but don
      ,flagReq  ["drop"] (\s opts -> Right $ setopt "drop" s opts) "N" "flat mode: omit N leading account name parts"
      ,flagReq  ["format"] (\s opts -> Right $ setopt "format" s opts) "FORMATSTR" "singlecolumn mode: use this custom line format"
      ,flagNone ["no-elide"] (\opts -> setboolopt "no-elide" opts) "tree mode: don't squash boring parent accounts"
-     ,flagNone ["historical","H"] (\opts -> setboolopt "historical" opts) "multicolumn mode: show historical ending balances"
-     ,flagNone ["cumulative"] (\opts -> setboolopt "cumulative" opts) "multicolumn mode: show accumulated ending balances"
+     ,flagNone ["historical","H"] (\opts -> setboolopt "historical" opts) "show historical ending balances, reflecting postings before report start"
+     ,flagNone ["cumulative"] (\opts -> setboolopt "cumulative" opts) "in multicolumn mode: show ending balances accumulated from 0 at report start"
      ,flagNone ["average","A"] (\opts -> setboolopt "average" opts) "multicolumn mode: show a row average column"
      ,flagNone ["row-total","T"] (\opts -> setboolopt "row-total" opts) "multicolumn mode: show a row total column"
      ,flagNone ["no-total","N"] (\opts -> setboolopt "no-total" opts) "don't show the final total row"
@@ -297,9 +297,19 @@ balance opts@CliOpts{reportopts_=ropts} j = do
           interval = interval_ ropts
           baltype  = balancetype_ ropts
           valuedate = fromMaybe d $ queryEndDate False $ queryFromOpts d ropts
+      -- shenanigans: use single/multiBalanceReport when we must,
+      -- ie when there's a report interval, or --historical or -- cumulative.
+      -- Otherwise prefer the older balanceReport since it can elide boring parents.
       case interval of
         NoInterval -> do
-          let report = balanceReport ropts (queryFromOpts d ropts) j
+          let report
+                -- For --historical/--cumulative, we must use multiBalanceReport.
+                -- (This forces --no-elide.)
+                | balancetype_ ropts `elem` [HistoricalBalance, CumulativeBalance]
+                  = let ropts' | flat_ ropts = ropts
+                               | otherwise   = ropts{accountlistmode_=ALTree}
+                    in singleBalanceReport ropts' (queryFromOpts d ropts) j
+                | otherwise = balanceReport ropts (queryFromOpts d ropts) j
               convert | value_ ropts = balanceReportValue j valuedate
                       | otherwise    = id
               render = case format of

hledger/doc/commands-balance.m4.md

@@ -17,10 +17,10 @@ Show accounts and their balances. Alias: bal.
 : in tree mode: don't squash boring parent accounts
 
 `-H --historical`
-: in multicolumn mode: show historical ending balances
+: show historical ending balances, reflecting postings before report start
 
 `--cumulative`
-: in multicolumn mode: show accumulated ending balances
+: in multicolumn mode: show ending balances accumulated from 0 at report start
 
 `-A --average`
 : in multicolumn mode: show a row average column