journal: account directives can declare account types

Previously you had to use one of the standard english account names
(assets, liabilities..) for top-level accounts, if you wanted to use
the bs/bse/cf/is commands.
Now, account directives can specify which of the big five categories
an account belongs to - asset, liability, equity, revenue or expense -
by writing one of the letters A, L, E, R or X two or more spaces after
the account name (where the numeric account code used to be).

This might change. Some thoughts influencing the current syntax:
- easy to type and read
- does not require multiple lines
- does not depend on any particular account numbering scheme
- allows more types later if needed
- still anglocentric, but only a little
- could be treated as syntactic sugar for account tags later
- seems to be compatible with (ignored by) current Ledger

The current design permits unlimited account type declarations anywhere
in the account tree. So you could declare a liability account somewhere
under assets, and maybe a revenue account under that, and another asset
account even further down. In such cases you start to see oddities like
accounts appearing in multiple places in a tree-mode report. In theory
the reports will still behave reasonably, but this has not been tested
too hard. In any case this is clearly too much freedom. I have left it
this way, for now, in case it helps with:

- modelling contra accounts ?
- multiple files. I suspect the extra expressiveness may come in handy
  when combining multiple files with account type declarations,
  rewriting account names, apply parent accounts etc.
  If we only allowed type declarations on top-level accounts, or
  only allowed a single account of each type, complications seem likely.

hledger-lib/Hledger/Data/Journal.hs

@@ -165,13 +165,14 @@ instance Sem.Semigroup Journal where
     ,jparsetimeclockentries     = jparsetimeclockentries j1 <> jparsetimeclockentries j2
     ,jincludefilestack          = jincludefilestack          j2
     ,jdeclaredaccounts          = jdeclaredaccounts          j1 <> jdeclaredaccounts          j2
+    ,jdeclaredaccounttypes      = jdeclaredaccounttypes      j1 <> jdeclaredaccounttypes      j2
     ,jcommodities               = jcommodities               j1 <> jcommodities               j2
     ,jinferredcommodities       = jinferredcommodities       j1 <> jinferredcommodities       j2
     ,jmarketprices              = jmarketprices              j1 <> jmarketprices              j2
     ,jtxnmodifiers              = jtxnmodifiers              j1 <> jtxnmodifiers              j2
     ,jperiodictxns              = jperiodictxns              j1 <> jperiodictxns              j2
     ,jtxns                      = jtxns                      j1 <> jtxns                      j2
-    ,jfinalcommentlines         = jfinalcommentlines         j2
+    ,jfinalcommentlines         = jfinalcommentlines         j2  -- XXX discards j1's ?
     ,jfiles                     = jfiles                     j1 <> jfiles                     j2
     ,jlastreadtime              = max (jlastreadtime j1) (jlastreadtime j2)
     }
@@ -193,8 +194,9 @@ nulljournal = Journal {
   ,jparsetimeclockentries     = []
   ,jincludefilestack          = []
   ,jdeclaredaccounts          = []
-  ,jcommodities               = M.fromList []
-  ,jinferredcommodities       = M.fromList []
+  ,jdeclaredaccounttypes      = M.empty
+  ,jcommodities               = M.empty
+  ,jinferredcommodities       = M.empty
   ,jmarketprices              = []
   ,jtxnmodifiers              = []
   ,jperiodictxns              = []

hledger-lib/Hledger/Data/Types.hs

@@ -113,7 +113,26 @@ instance Default Interval where def = NoInterval
 instance NFData Interval
 
 type AccountName = Text
-type AccountCode = Int
+
+data AccountType =
+    Asset
+  | Liability
+  | Equity
+  | Revenue
+  | Expense
+  deriving (Show,Eq,Ord,Data,Generic)
+
+instance NFData AccountType
+
+-- not worth the trouble, letters defined in accountdirectivep for now
+--instance Read AccountType
+--  where
+--    readsPrec _ ('A' : xs) = [(Asset,     xs)]
+--    readsPrec _ ('L' : xs) = [(Liability, xs)]
+--    readsPrec _ ('E' : xs) = [(Equity,    xs)]
+--    readsPrec _ ('R' : xs) = [(Revenue,   xs)]
+--    readsPrec _ ('X' : xs) = [(Expense,   xs)]
+--    readsPrec _ _ = []
 
 data AccountAlias = BasicAlias AccountName AccountName
                   | RegexAlias Regexp Replacement
@@ -369,6 +388,7 @@ data Journal = Journal {
   ,jincludefilestack      :: [FilePath]
   -- principal data
   ,jdeclaredaccounts      :: [AccountName]                          -- ^ Accounts declared by account directives, in parse order (after journal finalisation) 
+  ,jdeclaredaccounttypes  :: M.Map AccountType [AccountName]        -- ^ Accounts whose type has been declared in account directives (usually 5 top-level accounts) 
   ,jcommodities           :: M.Map CommoditySymbol Commodity        -- ^ commodities and formats declared by commodity directives
   ,jinferredcommodities   :: M.Map CommoditySymbol AmountStyle      -- ^ commodities and formats inferred from journal amounts  TODO misnamed - jusedstyles
   ,jmarketprices          :: [MarketPrice]

hledger-lib/Hledger/Read/Common.hs

@@ -43,6 +43,7 @@ module Hledger.Read.Common (
   getDefaultAmountStyle,
   getAmountStyle,
   pushDeclaredAccount,
+  addDeclaredAccountType,
   pushParentAccount,
   popParentAccount,
   getParentAccount,
@@ -311,6 +312,10 @@ getAmountStyle commodity = do
 pushDeclaredAccount :: AccountName -> JournalParser m ()
 pushDeclaredAccount acct = modify' (\j -> j{jdeclaredaccounts = acct : jdeclaredaccounts j})
 
+addDeclaredAccountType :: AccountName -> AccountType -> JournalParser m ()
+addDeclaredAccountType acct atype = 
+  modify' (\j -> j{jdeclaredaccounttypes = M.insertWith (++) atype [acct] (jdeclaredaccounttypes j)})
+
 pushParentAccount :: AccountName -> JournalParser m ()
 pushParentAccount acct = modify' (\j -> j{jparseparentaccounts = acct : jparseparentaccounts j})
 

hledger-lib/Hledger/Read/JournalReader.hs

@@ -69,6 +69,7 @@ import Control.Monad
 import Control.Monad.Except (ExceptT(..))
 import Control.Monad.State.Strict
 import Data.Bifunctor (first)
+import Data.Maybe
 import qualified Data.Map.Strict as M
 import Data.Text (Text)
 import Data.String
@@ -257,10 +258,29 @@ accountdirectivep :: JournalParser m ()
 accountdirectivep = do
   string "account"
   lift (skipSome spacenonewline)
-  acct <- modifiedaccountnamep  -- account directives can be modified by alias/apply account
-  _ :: Maybe String <- (optional $ lift $ skipSome spacenonewline >> some digitChar)  -- compatibility: ignore account codes supported in 1.9/1.10
+  -- the account name, possibly modified by preceding alias or apply account directives
+  acct <- modifiedaccountnamep
+  -- and maybe something else after two or more spaces ?
+  matype :: Maybe AccountType <- lift $ fmap (fromMaybe Nothing) $ optional $ do
+    skipSome spacenonewline -- at least one more space in addition to the one consumed by modifiedaccountp 
+    choice [
+      -- a numeric account code, as supported in 1.9-1.10 ? currently ignored
+       some digitChar >> return Nothing
+      -- a letter account type code (ALERX), as added in 1.11 ?
+      ,char 'A' >> return (Just Asset) 
+      ,char 'L' >> return (Just Liability) 
+      ,char 'E' >> return (Just Equity) 
+      ,char 'R' >> return (Just Revenue) 
+      ,char 'X' >> return (Just Expense) 
+      ]
   newline
+  -- Ledger-style indented subdirectives on following lines ? ignore
   skipMany indentedlinep
+
+  -- update the journal
+  case matype of
+    Nothing    -> return ()
+    Just atype -> addDeclaredAccountType acct atype
   pushDeclaredAccount acct
 
 indentedlinep :: JournalParser m String