bin: add hledger-swap-dates

bin/README.md

@@ -10,6 +10,7 @@ They are:
 
 - hledger-check.hs      - check more complex account balance assertions
 - hledger-smooth.hs     - an attempt at automatically splitting infrequent/irregular transactions
+- hledger-swap-dates.hs - swap all date and date2 fields
 
 A reminder from http://hledger.org/hledger.html#add-on-commands :
 when using the main hledger executable to run add-on commands, remember

bin/hledger-swap-dates.hs

@@ -0,0 +1,42 @@
+#!/usr/bin/env stack
+{- stack runghc --verbosity info
+   --package hledger-lib
+   --package hledger
+   --package here
+   --package text
+-}
+
+{-# LANGUAGE QuasiQuotes #-}
+{-# OPTIONS_GHC -Wno-missing-signatures -Wno-name-shadowing #-}
+
+import Data.List
+import Data.String.Here
+import qualified Data.Text.IO as T
+import Hledger
+import Hledger.Cli
+
+------------------------------------------------------------------------------
+cmdmode = hledgerCommandMode
+  [here| swap-dates
+Swap date and date2, on transactions and postings which have date2 defined.
+FLAGS
+  |]
+  [] 
+  [generalflagsgroup1]
+  []
+  ([], Nothing) -- Just $ argsFlag "[QUERY]")
+------------------------------------------------------------------------------
+
+main :: IO ()
+main = do
+  opts <- getHledgerCliOpts cmdmode
+  withJournalDo opts $
+   \CliOpts{rawopts_=_rawopts,reportopts_=ropts} j -> do
+    d <- getCurrentDay
+    let
+      q = queryFromOpts d ropts
+      ts = filter (q `matchesTransaction`) $ jtxns $ journalSelectingAmountFromOpts ropts j
+      tags = nub $ sort $ map fst $ concatMap transactionAllTags ts
+    mapM_ T.putStrLn tags
+    -- replace txns with date-swapped txns
+    -- print txns