;refactor: extracted reportPeriodName for making report headings

hledger-lib/Hledger/Reports/BudgetReport.hs

@@ -260,20 +260,17 @@ budgetReportAsText ropts@ReportOpts{..} budgetr =
 budgetReportAsTable :: ReportOpts -> BudgetReport -> Table String String (Maybe MixedAmount, Maybe MixedAmount)
 budgetReportAsTable
   ropts@ReportOpts{balancetype_}
-  (PeriodicReport periods rows (PeriodicReportRow _ coltots grandtot grandavg)) =
+  (PeriodicReport spans rows (PeriodicReportRow _ coltots grandtot grandavg)) =
     addtotalrow $
     Table
       (T.Group NoLine $ map Header accts)
       (T.Group NoLine $ map Header colheadings)
       (map rowvals rows)
   where
-    colheadings = map mkheading periods
+    colheadings = map (reportPeriodName balancetype_ spans) spans
                   ++ ["  Total" | row_total_ ropts]
                   ++ ["Average" | average_ ropts]
-      where
+
-        mkheading = case balancetype_ of
-          PeriodChange -> showDateSpanMonthAbbrev
-          _            -> maybe "" (showDate . prevday) . spanEnd
     accts = map renderacct rows
     -- FIXME. Have to check explicitly for which to render here, since
     -- budgetReport sets accountlistmode to ALTree. Find a principled way to do
@@ -290,6 +287,25 @@ budgetReportAsTable
                                ++ [grandavg | average_ ropts && not (null coltots)]
                     ))
 
+-- | Make a name for the given period in a multiperiod report, given
+-- the type of balance being reported and the full set of report
+-- periods. This will be used as a column heading (or row heading, in
+-- a register summary report). We try to pick a useful name as follows:
+--
+-- - ending-balance reports: the period's end date
+--
+-- - balance change reports where the periods are months and all in the same year:
+--   the short month name in the current locale
+--
+-- - all other balance change reports: a description of the datespan,
+--   abbreviated to compact form if possible (see showDateSpan).
+--
+reportPeriodName :: BalanceType -> [DateSpan] -> DateSpan -> String
+reportPeriodName balancetype spans =
+  case balancetype of
+    PeriodChange -> showDateSpanMonthAbbrev
+    _            -> maybe "" (showDate . prevday) . spanEnd
+
 -- tests
 
 tests_BudgetReport = tests "BudgetReport" [

hledger/Hledger/Cli/Commands/Balance.hs

@@ -593,7 +593,7 @@ multiBalanceReportAsText ropts@ReportOpts{..} r =
 -- | Build a 'Table' from a multi-column balance report.
 balanceReportAsTable :: ReportOpts -> MultiBalanceReport -> Table String String MixedAmount
 balanceReportAsTable opts@ReportOpts{average_, row_total_, balancetype_}
-    (PeriodicReport colspans items (PeriodicReportRow _ coltotals tot avg)) =
+    (PeriodicReport spans items (PeriodicReportRow _ coltotals tot avg)) =
    maybetranspose $
    addtotalrow $
    Table
@@ -602,13 +602,9 @@ balanceReportAsTable opts@ReportOpts{average_, row_total_, balancetype_}
      (map rowvals items)
   where
     totalscolumn = row_total_ && balancetype_ `notElem` [CumulativeChange, HistoricalBalance]
-    colheadings = map mkheading colspans
+    colheadings = map (reportPeriodName balancetype_ spans) spans
                   ++ ["  Total" | totalscolumn]
                   ++ ["Average" | average_]
-      where
-        mkheading = case balancetype_ of
-          PeriodChange -> showDateSpanMonthAbbrev
-          _            -> maybe "" (showDate . prevday) . spanEnd
     accts = map renderacct items
     renderacct row =
         replicate ((prrDepth row - 1) * 2) ' ' ++ T.unpack (prrDisplayName row)