Add Support for Rewriting Multipler Postings Into Different Commodities (#557)

When generating a new posting as a multiple of an existing posting,
support conversion to a different commodity.  For example, postings in
hours can be used to generate postings in USD.

Automatic transactions generated from rewrite rules use the commodity,
amount style, and transaction price if the rewrite defines a commodity.

bin/hledger-rewrite.hs

@@ -60,12 +60,15 @@ More:
 $ hledger rewrite -- [QUERY]        --add-posting "ACCT  AMTEXPR" ...
 $ hledger rewrite -- ^income        --add-posting '(liabilities:tax)  *.33'
 $ hledger rewrite -- expenses:gifts --add-posting '(budget:gifts)  *-1"'
+$ hledger rewrite -- ^income        --add-posting '(budget:foreign currency)  *0.25 JPY; diversify'
 ```
 
 Argument for `--add-posting` option is a usual posting of transaction with an
-exception for amount specification. More precisely you can use `'*'` (star
-symbol) in place of currency to indicate that that this is a factor for an
-amount of original matched posting.
+exception for amount specification. More precisely, you can use `'*'` (star
+symbol) before the amount to indicate that that this is a factor for an
+amount of original matched posting.  If the amount includes a commodity name,
+the new posting amount will be in the new commodity; otherwise, it will be in
+the matched posting amount's commodity.
 
 #### Re-write rules in a file
 

hledger-lib/Hledger/Data/Amount.hs

@@ -151,7 +151,7 @@ instance Num Amount where
 
 -- | The empty simple amount.
 amount, nullamt :: Amount
-amount = Amount{acommodity="", aquantity=0, aprice=NoPrice, astyle=amountstyle}
+amount = Amount{acommodity="", aquantity=0, aprice=NoPrice, astyle=amountstyle, amultiplier=False}
 nullamt = amount
 
 -- | A temporary value for parsed transactions which had no amount specified.

hledger-lib/Hledger/Data/AutoTransaction.hs

@@ -55,7 +55,7 @@ import Hledger.Query
 --     ping         $1.00
 -- <BLANKLINE>
 -- <BLANKLINE>
--- >>> runModifierTransaction Any (ModifierTransaction "ping" ["pong" `post` amount{acommodity="*", aquantity=3}]) nulltransaction{tpostings=["ping" `post` usd 2]}
+-- >>> runModifierTransaction Any (ModifierTransaction "ping" ["pong" `post` amount{amultiplier=True, aquantity=3}]) nulltransaction{tpostings=["ping" `post` usd 2]}
 -- 0000/01/01
 --     ping         $2.00
 --     pong         $6.00
@@ -107,7 +107,7 @@ tdates t = tdate t : concatMap pdates (tpostings t) ++ maybeToList (tdate2 t) wh
 postingScale :: Posting -> Maybe Quantity
 postingScale p =
     case amounts $ pamount p of
-        [a] | acommodity a == "*" -> Just $ aquantity a
+        [a] | amultiplier a -> Just $ aquantity a
         _ -> Nothing
 
 runModifierPosting :: Posting -> (Posting -> Posting)
@@ -117,10 +117,12 @@ runModifierPosting p' = modifier where
         , pdate2 = pdate2 p
         , pamount = amount' p
         }
-    amount' =
-        case postingScale p' of
-            Nothing -> const $ pamount p'
-            Just n -> \p -> pamount p `divideMixedAmount` (1/n)
+    amount' = case postingScale p' of
+        Nothing -> const $ pamount p'
+        Just n -> \p -> withAmountType (head $ amounts $ pamount p') $ pamount p `divideMixedAmount` (1/n)
+    withAmountType amount (Mixed as) = case acommodity amount of
+        "" -> Mixed as
+        c -> Mixed [a{acommodity = c, astyle = astyle amount, aprice = aprice amount} | a <- as]
 
 renderPostingCommentDates :: Posting -> Posting
 renderPostingCommentDates p = p { pcomment = comment' }

hledger-lib/Hledger/Data/Commodity.hs

@@ -24,7 +24,7 @@ import Hledger.Utils
 
 
 -- characters that may not be used in a non-quoted commodity symbol
-nonsimplecommoditychars = "0123456789-+.@;\n \"{}=" :: [Char]
+nonsimplecommoditychars = "0123456789-+.@*;\n \"{}=" :: [Char]
 
 quoteCommoditySymbolIfNeeded s | any (`elem` nonsimplecommoditychars) (T.unpack s) = "\"" <> s <> "\""
                                | otherwise = s

hledger-lib/Hledger/Data/Types.hs

@@ -158,10 +158,11 @@ data Commodity = Commodity {
 instance NFData Commodity
 
 data Amount = Amount {
-      acommodity :: CommoditySymbol,
-      aquantity  :: Quantity,
-      aprice     :: Price,           -- ^ the (fixed) price for this amount, if any
-      astyle     :: AmountStyle
+      acommodity  :: CommoditySymbol,
+      aquantity   :: Quantity,
+      aprice      :: Price,           -- ^ the (fixed) price for this amount, if any
+      astyle      :: AmountStyle,
+      amultiplier :: Bool             -- ^ amount is a multipier for AutoTransactions
     } deriving (Eq,Ord,Typeable,Data,Generic)
 
 instance NFData Amount

hledger-lib/Hledger/Read/Common.hs

@@ -371,30 +371,39 @@ signp = do
   return $ case sign of Just '-' -> "-"
                         _        -> ""
 
+multiplierp :: TextParser m Bool
+multiplierp = do
+  multiplier <- optional $ oneOf ("*" :: [Char])
+  return $ case multiplier of Just '*' -> True
+                              _        -> False
+
 leftsymbolamountp :: Monad m => JournalStateParser m Amount
 leftsymbolamountp = do
   sign <- lift signp
+  m <- lift multiplierp
   c <- lift commoditysymbolp
   sp <- lift $ many spacenonewline
   (q,prec,mdec,mgrps) <- lift numberp
   let s = amountstyle{ascommodityside=L, ascommodityspaced=not $ null sp, asprecision=prec, asdecimalpoint=mdec, asdigitgroups=mgrps}
   p <- priceamountp
   let applysign = if sign=="-" then negate else id
-  return $ applysign $ Amount c q p s
+  return $ applysign $ Amount c q p s m
   <?> "left-symbol amount"
 
 rightsymbolamountp :: Monad m => JournalStateParser m Amount
 rightsymbolamountp = do
+  m <- lift multiplierp
   (q,prec,mdec,mgrps) <- lift numberp
   sp <- lift $ many spacenonewline
   c <- lift commoditysymbolp
   p <- priceamountp
   let s = amountstyle{ascommodityside=R, ascommodityspaced=not $ null sp, asprecision=prec, asdecimalpoint=mdec, asdigitgroups=mgrps}
-  return $ Amount c q p s
+  return $ Amount c q p s m
   <?> "right-symbol amount"
 
 nosymbolamountp :: Monad m => JournalStateParser m Amount
 nosymbolamountp = do
+  m <- lift multiplierp
   (q,prec,mdec,mgrps) <- lift numberp
   p <- priceamountp
   -- apply the most recently seen default commodity and style to this commodityless amount
@@ -402,7 +411,7 @@ nosymbolamountp = do
   let (c,s) = case defcs of
         Just (defc,defs) -> (defc, defs{asprecision=max (asprecision defs) prec})
         Nothing          -> ("", amountstyle{asprecision=prec, asdecimalpoint=mdec, asdigitgroups=mgrps})
-  return $ Amount c q p s
+  return $ Amount c q p s m
   <?> "no-symbol amount"
 
 commoditysymbolp :: TextParser m CommoditySymbol

tests/bin/rewrite.test

@@ -49,6 +49,80 @@
 >>>2
 >>>=0
 
+# Add postings in another commodity
+../../bin/hledger-rewrite -f-
+<<<
+2017/04/24 * 09:00-09:25
+    (assets:unbilled:client1)         0.42h
+
+2017/04/25 * 10:00-11:15
+    (assets:unbilled:client1)         1.25h
+
+2017/04/25 * 14:00-15:32
+    (assets:unbilled:client2)         1.54h
+
+; billing rules
+= ^assets:unbilled:client1
+  (assets:to bill:client1)   *100.00 CAD
+
+= ^assets:unbilled:client2
+  (assets:to bill:client2)   *150.00 CAD
+>>>
+2017/04/24 * 09:00-09:25
+    (assets:unbilled:client1)         0.42h
+    (assets:to bill:client1)     42.00 CAD
+
+2017/04/25 * 10:00-11:15
+    (assets:unbilled:client1)         1.25h
+    (assets:to bill:client1)    125.00 CAD
+
+2017/04/25 * 14:00-15:32
+    (assets:unbilled:client2)         1.54h
+    (assets:to bill:client2)    231.00 CAD
+
+>>>2
+>>>=0
+
+
+# Add postings with prices
+../../bin/hledger-rewrite -f- -B
+<<<
+2017/04/24 * 09:00-09:25
+    (assets:unbilled:client1)         0.42h
+
+2017/04/25 * 10:00-11:15
+    (assets:unbilled:client1)         1.25h
+
+2017/04/25 * 14:00-15:32
+    (assets:unbilled:client2)         1.54h
+
+; billing rules
+= ^assets:unbilled:client1
+  assets:to bill:client1   *1.00 hours @ $100.00
+  income:consulting:client1
+
+= ^assets:unbilled:client2
+  assets:to bill:client2   *1.00 hours @ $150.00
+  income:consulting:client2
+>>>
+2017/04/24 * 09:00-09:25
+    (assets:unbilled:client1)         0.42h
+    assets:to bill:client1           $42.00
+    income:consulting:client1
+
+2017/04/25 * 10:00-11:15
+    (assets:unbilled:client1)         1.25h
+    assets:to bill:client1          $125.00
+    income:consulting:client1
+
+2017/04/25 * 14:00-15:32
+    (assets:unbilled:client2)         1.54h
+    assets:to bill:client2          $231.00
+    income:consulting:client2
+
+>>>2
+>>>=0
+
 # Add absolute bank processing fee
 ../../bin/hledger-rewrite -f- assets:bank and 'amt:<0' --add-posting 'expenses:fee  $5'  --add-posting 'assets:bank  $-5'
 <<<