transliteration via configuration file: ps -to=file or ps -from=file

src/compiler/GF/Command/Commands.hs

@@ -628,14 +628,18 @@ allCommands env@(pgf, mos) = Map.fromList [
        "gr -cat=QCl | l | ps -bind      -- linearization output from LangFin", 
        "ps -to_devanagari \"A-p\"         -- show Devanagari in UTF8 terminal",
        "rf -file=Hin.gf | ps -env=quotes -to_devanagari -- convert translit to UTF8",
-       "rf -file=Ara.gf | ps -from_utf8 -env=quotes -from_arabic -- convert UTF8 to transliteration"
+       "rf -file=Ara.gf | ps -from_utf8 -env=quotes -from_arabic -- convert UTF8 to transliteration",
+       "ps -to=chinese.trans \"abc\"      -- apply transliteration defined in file chinese.trans"
        ],
-     exec = \opts -> 
-               let (os,fs) = optsAndFlags opts in
-               return . fromString . stringOps (envFlag fs) (map prOpt os) . toString,
+     exec = \opts x -> do
+               let (os,fs) = optsAndFlags opts
+               trans <- optTranslit opts 
+               return ((fromString . trans . stringOps (envFlag fs) (map prOpt os) . toString) x),
      options = stringOpOptions,
      flags = [
-       ("env","apply in this environment only")
+       ("env","apply in this environment only"),
+       ("from","backward-apply transliteration defined in this file (format 'unicode translit' per line)"),
+       ("to",  "forward-apply transliteration defined in this file")
        ]
      }),
   ("pt", emptyCommandInfo {
@@ -1100,6 +1104,15 @@ allCommands env@(pgf, mos) = Map.fromList [
        probs <- readProbabilitiesFromFile file pgf
        return (setProbabilities probs pgf)
 
+   optTranslit opts = case (valStrOpts "to" "" opts, valStrOpts "from" "" opts) of
+     ("","")  -> return id
+     (file,"") -> do
+       src <- readFile file 
+       return $ transliterateWithFile file src False
+     (_,file) -> do
+       src <- readFile file 
+       return $ transliterateWithFile file src True
+
    optFile opts = valStrOpts "file" "_gftmp" opts
 
    optType opts = 

src/compiler/GF/Text/Transliterations.hs

@@ -1,5 +1,6 @@
 module GF.Text.Transliterations (
   transliterate,
+  transliterateWithFile,
   transliteration,
   characterTable,
   transliterationPrintNames
@@ -27,6 +28,10 @@ transliterate s = case s of
   't':'o':'_':t -> fmap appTransToUnicode $ transliteration t
   _ -> Nothing
 
+transliterateWithFile :: String -> String -> Bool -> (String -> String)
+transliterateWithFile name src isFrom =
+  (if isFrom then appTransFromUnicode else appTransToUnicode) (getTransliterationFile name src)
+
 transliteration :: String -> Maybe Transliteration
 transliteration s = Map.lookup s allTransliterations 
 
@@ -82,6 +87,14 @@ mkTransliteration name ts us =
     tzip ts us = [(t,u) | (t,u) <- zip ts us, t /= "-"]
     uzip us ts = [(u,t) | (u,t) <- zip us ts, t /= "-"]
 
+getTransliterationFile :: String -> String -> Transliteration
+getTransliterationFile name = uncurry (mkTransliteration name) . codes
+ where
+  codes = unzip . map (mkOne . words) . lines
+  mkOne ws = case ws of
+    [c]:t:_ -> (t,fromEnum c)  -- ä a:
+    u:t:_   -> (t,read u)      -- 228 a: OR 0xe4
+    _ -> error $ "not a valid transliteration:" ++ unwords ws
 
 unchar :: String -> [String]
 unchar s = case s of