Make Ident abstract; imports of Data.ByteString.Char8 down from 29 to 16 modules

Most of the explicit uses of ByteStrings were eliminated by using identS,

	identS = identC . BS.pack 

which was found in GF.Grammar.CF and moved to GF.Infra.Ident. The function

	prefixIdent :: String -> Ident -> Ident

allowed one additional import of ByteString to be eliminated. The functions

	isArgIdent :: Ident -> Bool
	getArgIndex :: Ident -> Maybe Int

were needed to eliminate explicit pattern matching on Ident from two modules.

3 files changed, 23 insertions, 7 deletions

diff --git a/src/compiler/GF/Infra/Ident.hs b/src/compiler/GF/Infra/Ident.hs
index 967945be9..bb26ea98c 100644
--- a/src/compiler/GF/Infra/Ident.hs
+++ b/src/compiler/GF/Infra/Ident.hs
@@ -13,9 +13,10 @@
 -----------------------------------------------------------------------------
 
 module GF.Infra.Ident (-- * Identifiers
-	      Ident(..), ident2bs, showIdent, ppIdent,
-	      identC, identV, identA, identAV, identW,
-	      argIdent, varStr, varX, isWildIdent, varIndex,
+	      Ident, ident2bs, showIdent, ppIdent, prefixIdent,
+	      identS, identC, identV, identA, identAV, identW,
+	      argIdent, isArgIdent, getArgIndex,
+              varStr, varX, isWildIdent, varIndex,
 	      -- * refreshing identifiers
 	      IdState, initIdStateN, initIdState,
 	      lookVar, refVar, refVarPlus
@@ -23,6 +24,7 @@ module GF.Infra.Ident (-- * Identifiers
 
 import GF.Data.Operations
 import qualified Data.ByteString.Char8 as BS
+import Data.Char(isDigit)
 import Text.PrettyPrint
 
 
@@ -54,6 +56,9 @@ showIdent i = BS.unpack $! ident2bs i
 ppIdent :: Ident -> Doc
 ppIdent = text . showIdent
 
+identS :: String -> Ident
+identS = identC . BS.pack
+
 identC :: BS.ByteString -> Ident
 identV :: BS.ByteString -> Int -> Ident
 identA :: BS.ByteString -> Int -> Ident
@@ -62,6 +67,10 @@ identW :: Ident
 (identC, identV, identA, identAV, identW) = 
     (IC,     IV,     IA,     IAV,     IW)
 
+
+prefixIdent :: String -> Ident -> Ident
+prefixIdent pref = identC . BS.append (BS.pack pref) . ident2bs
+
 -- normal identifier
 -- ident s = IC s
 
@@ -70,6 +79,16 @@ argIdent :: Int -> Ident -> Int -> Ident
 argIdent 0 (IC c) i = identA  c i
 argIdent b (IC c) i = identAV c b i
 
+isArgIdent IA{}  = True
+isArgIdent IAV{} = True
+isArgIdent _     = False
+
+getArgIndex (IA _ i)    = Just i
+getArgIndex (IAV _ _ i) = Just i
+getArgIndex (IC s)
+  | isDigit (BS.last s) = (Just . read . BS.unpack . snd . BS.spanEnd isDigit) s
+getArgIndex x = Nothing
+
 -- | used in lin defaults
 varStr :: Ident
 varStr = identA (BS.pack "str") 0
diff --git a/src/compiler/GF/Infra/Option.hs b/src/compiler/GF/Infra/Option.hs
index c4aecae23..554468783 100644
--- a/src/compiler/GF/Infra/Option.hs
+++ b/src/compiler/GF/Infra/Option.hs
@@ -42,8 +42,6 @@ import GF.Data.ErrM
 
 import Data.Set (Set)
 import qualified Data.Set as Set
-import qualified Data.ByteString.Char8 as BS
-
 
 
 usageHeader :: String
@@ -398,7 +396,7 @@ optDescr =
                          Just p  -> set $ \o -> o { optHaskellOptions = Set.insert p (optHaskellOptions o) }
                          Nothing -> fail $ "Unknown Haskell option: " ++ x
                                             ++ " Known: " ++ show (map fst haskellOptionNames)
-       literalCat  x = set $ \o -> o { optLiteralCats = foldr Set.insert (optLiteralCats o) ((map (identC . BS.pack) . splitBy (==',')) x) }
+       literalCat  x = set $ \o -> o { optLiteralCats = foldr Set.insert (optLiteralCats o) ((map identS . splitBy (==',')) x) }
        lexicalCat  x = set $ \o -> o { optLexicalCats = foldr Set.insert (optLexicalCats o) (splitBy (==',') x) }
        outDir      x = set $ \o -> o { optOutputDir = Just x }
        gfLibPath   x = set $ \o -> o { optGFLibPath = Just x }
diff --git a/src/compiler/GF/Infra/UseIO.hs b/src/compiler/GF/Infra/UseIO.hs
index 2fdc42d83..140c2623f 100644
--- a/src/compiler/GF/Infra/UseIO.hs
+++ b/src/compiler/GF/Infra/UseIO.hs
@@ -34,7 +34,6 @@ import Text.Printf
 import Control.Monad
 import Control.Monad.Trans(MonadIO(..))
 import Control.Exception(evaluate)
-import qualified Data.ByteString.Char8 as BS
 
 putShow' :: Show a => (c -> a) -> c -> IO ()
 putShow' f = putStrLn . show . length . show . f