cli: add a hidden --version+ flag showing number representation (#118)

hledger-lib/Hledger/Data/Types.hs

@@ -52,8 +52,10 @@ type Commodity = String
 
 -- | The basic numeric type used in amounts. Different implementations
 -- can be selected via cabal flag for testing and benchmarking purposes.
+numberRepresentation :: String
 #ifdef DOUBLE
 type Quantity = Double
+numberRepresentation = "Double"
 #else
 type Quantity = Decimal
 deriving instance Data (Quantity)
@@ -62,6 +64,7 @@ deriving instance Data (Quantity)
 instance ToMarkup (Quantity) 
  where
    toMarkup = toMarkup . show
+numberRepresentation = "Decimal"
 #endif
 
 -- | An amount's price (none, per unit, or total) in another commodity.

hledger/Hledger/Cli/Main.hs

@@ -111,7 +111,9 @@ mainmode addons = defMode {
      -- flags in the unnamed group, shown last without a heading:
     ,groupUnnamed = []
      -- flags accepted but not shown in the help:
-    ,groupHidden = inputflags -- included here so they'll not raise a confusing error if present with no COMMAND
+    ,groupHidden =
+        detailedversionflag :
+        inputflags -- included here so they'll not raise a confusing error if present with no COMMAND
     }
  }
 
@@ -225,8 +227,8 @@ main = do
     isBadCommand         = not (null rawcmd) && null cmd
     hasHelp args         = any (`elem` args) ["--help","-h","-?"]
     hasVersion           = ("--version" `elem`)
+    hasDetailedVersion   = ("--version+" `elem`)
     generalHelp          = putStr $ showModeHelp $ mainmode addonDisplayNames
-    version              = putStrLn prognameandversion
     badCommandError      = error' ("command "++rawcmd++" is not recognized, run with no command to see a list") >> exitFailure
     f `orShowHelp` mode  = if hasHelp args then putStr (showModeHelp mode) else f
   dbgM "processed opts" opts
@@ -244,7 +246,9 @@ main = do
       -- high priority flags and situations. --help should be highest priority.
       | hasHelp argsbeforecmd    = dbgM "" "--help before command, showing general help" >> generalHelp
       | not (hasHelp argsaftercmd) && (hasVersion argsbeforecmd || (hasVersion argsaftercmd && isInternalCommand))
-                                 = version
+                                 = putStrLn prognameandversion
+      | not (hasHelp argsaftercmd) && (hasDetailedVersion argsbeforecmd || (hasDetailedVersion argsaftercmd && isInternalCommand))
+                                 = putStrLn prognameanddetailedversion
       -- \| (null externalcmd) && "binary-filename" `inRawOpts` rawopts = putStrLn $ binaryfilename progname
       -- \| "--browse-args" `elem` args     = System.Console.CmdArgs.Helper.execute "cmdargs-browser" mainmode' args >>= (putStr . show)
       | isNullCommand            = dbgM "" "no command, showing general help" >> generalHelp

hledger/Hledger/Cli/Options.hs

@@ -10,6 +10,7 @@ module Hledger.Cli.Options (
 
   -- * cmdargs flags & modes
   helpflags,
+  detailedversionflag,
   inputflags,
   reportflags,
   generalflagsgroup1,
@@ -85,6 +86,10 @@ helpflags = [
  ,flagNone ["version"] (setboolopt "version") "show version information"
  ]
 
+-- | A hidden flag, just for the hledger executable.
+detailedversionflag :: Flag RawOpts
+detailedversionflag = flagNone ["version+"] (setboolopt "version+") "show version information with extra detail"
+
 -- | Common input-related flags: --file, --rules-file, --alias...
 inputflags :: [Flag RawOpts]
 inputflags = [

hledger/Hledger/Cli/Version.hs

@@ -7,17 +7,19 @@ module Hledger.Cli.Version (
   progname,
   version,
   prognameandversion,
+  prognameanddetailedversion,
   binaryfilename
 )
 where
 import System.Info (os, arch)
 import Text.Printf
 
+import Hledger.Data.Types (numberRepresentation)
 import Hledger.Utils
 
 
 -- package name and version from the cabal file
-progname, version, prognameandversion :: String
+progname, version, prognameandversion, prognameanddetailedversion :: String
 progname = "hledger"
 #ifdef VERSION
 version = VERSION
@@ -25,6 +27,7 @@ version = VERSION
 version = ""
 #endif
 prognameandversion = progname ++ " " ++ version
+prognameanddetailedversion = printf "%s %s, using %s" progname version numberRepresentation
 
 -- developer build version strings include PATCHLEVEL (number of
 -- patches since the last tag). If defined, it must be a number.