begin arbitrary currency support

Currency.hs

@@ -1,5 +1,7 @@
 module Currency
 where
+import qualified Data.Map as Map
+import Data.Map ((!))
 import Utils
 import Types
 
@@ -12,8 +14,10 @@ currencies =
     ,Currency "m"   1          -- minutes
     ]
 
+currencymap = Map.fromList [(sym, c) | c@(Currency sym rate) <- currencies]
+
 getcurrency :: String -> Currency
-getcurrency s = head $ [(Currency symbol rate) | (Currency symbol rate) <- currencies, symbol==s]
+getcurrency s = Map.findWithDefault (Currency s 1) s currencymap
 
 conversionRate :: Currency -> Currency -> Double
 conversionRate oldc newc = (rate newc) / (rate oldc)

Ledger.hs

@@ -2,7 +2,6 @@ module Ledger
 where
 import qualified Data.Map as Map
 import Data.Map ((!))
-
 import Utils
 import Types
 import Amount

NOTES

@@ -2,37 +2,27 @@ hledger project notes
 
 * TO DO
 ** bugs
-*** handle unknown currencies
-** compatibility
-** basic features
-*** print
-*** !include
-*** -j and -J graph data output
-
-** advanced features
-*** handle mixed amounts
-*** ledger 3.0-style elision
-*** -p period expressions
-*** -d display expressions
-*** read gnucash files
-*** other args, directives
-
-*** more speed
-** new features
-*** feature: read timelog files
-**** fix up Amounts
-***** allow flexible display by currency
-***** allow parsing by currency
-***** fix arithmetic
-
-**** timelog parser
-    handle time amounts
+** ledger features
+*** print command
+*** handle mixed amounts, non-money currencies
+**** handle precision per currency
+*** handle time logs
+**** fix timelog parser
+**** handle time amounts
      switch to Data.Time.*
       fix errors
        - read seconds to pico
        try System.Time ?
-
-*** timelog simple format
+*** !include
+*** -j and -J graph data output
+*** more speed
+*** ledger 3.0-style elision
+*** -p period expressions
+*** -d display expressions
+*** read gnucash files
+*** other ledger args, directives
+** new features
+*** simpler timelog format
 *** auto-generate missing clock-out
 *** graph automation
 *** entry and smart data entry

Utils.hs

@@ -4,6 +4,7 @@ module Utils (
               module Char,
               module Data.List,
               module Data.Tree,
+              module Data.Map,
               module Data.Ord,
               module Text.Printf,
               module Text.Regex,
@@ -15,6 +16,7 @@ where
 import Char
 import Data.List
 import Data.Tree
+import qualified Data.Map
 import Data.Ord
 import Text.Printf
 import Text.Regex