pruneBoringBranches again, a test, and fix hiding of zero-balance leaf accounts

BalanceCommand.hs

@@ -131,10 +131,20 @@ showLedgerAccountBalances l maxdepth =
     then ""
     else printf "--------------------\n%20s\n" $ showAmountRounded total
     where 
-      acctbranches = branches $ ledgerAccountTree maxdepth l
+      acctbranches = branches $ pruneBoringBranches $ ledgerAccountTree maxdepth l
       filteredacctbranches = branches $ ledgerFilteredAccountTree maxdepth (acctpat l) l
       total = sum $ map (abalance . root) filteredacctbranches
 
+-- | Remove boring branches and leaves from a tree of accounts.
+-- A boring branch contains only accounts which have a 0 balance.
+pruneBoringBranches :: Tree Account -> Tree Account
+pruneBoringBranches =
+--    treefilter hastxns . 
+    treefilter hasbalance
+    where 
+      hasbalance = not . isZeroAmount . abalance
+      hastxns = (> 0) . length . atransactions
+
 -- | Get the string representation of a tree of accounts.
 -- The ledger from which the accounts come is required so that
 -- we can check for boring accounts.

Tests.hs

@@ -15,7 +15,7 @@ import RegisterCommand
 -- quickcheck = mapM quickCheck ([
 --         ] :: [Bool])
 
-runhunit = runTestTT alltests
+runtests = runTestTT alltests
 
 alltests = concattests [
             tests
@@ -93,6 +93,10 @@ tests =
         assertparseequal (Amount (getcurrency "$") 47.18 2) (parsewith ledgeramount " $47.18")
         assertparseequal (Amount (getcurrency "$") 1 0) (parsewith ledgeramount " $1.")
 
+        ,"pruneBoringBranches" ~: do
+           atree <- liftM (ledgerAccountTree 99) $ ledgerfromfile "sample.ledger"
+           assertequal 13 (length $ flatten $ atree)
+           assertequal 12 (length $ flatten $ pruneBoringBranches $ atree)
  ]
 
 balancecommandtests = 
@@ -156,6 +160,7 @@ balancecommandtests =
 assertparseequal :: (Show a, Eq a) => a -> (Either ParseError a) -> Assertion
 assertparseequal expected parsed = either printParseError (assertequal expected) parsed
 
+
 -- test data
 
 rawtransaction1_str  = "  expenses:food:dining  $10.00\n"

hledger.hs

@@ -8,8 +8,7 @@ Released under GPL version 3 or later.
 This is a minimal haskell clone of John Wiegley's ledger
 <http://newartisans.com/software/ledger.html>.  hledger generates
 simple ledger-compatible register & balance reports from a plain text
-ledger file, and demonstrates a (naive) purely functional
+ledger file, and demonstrates a functional implementation of ledger.
-implementation of ledger.
 
 -}
 
@@ -33,10 +32,10 @@ main = do
       run cmd opts args
        | Help `elem` opts            = putStr usage
        | Version `elem` opts         = putStr version
-       | cmd `isPrefixOf` "selftest" = runhunit >> return ()
+       | cmd `isPrefixOf` "balance"  = parseLedgerAndDo opts args printbalance
        | cmd `isPrefixOf` "print"    = parseLedgerAndDo opts args printentries
        | cmd `isPrefixOf` "register" = parseLedgerAndDo opts args printregister
-       | cmd `isPrefixOf` "balance"  = parseLedgerAndDo opts args printbalance
+       | cmd `isPrefixOf` "test"     = runtests >> return ()
        | otherwise                   = putStr usage
 
 -- | parse the user's specified ledger file and do some action with it