Added SRGS ABNF generation.

2 files changed, 142 insertions, 4 deletions

diff --git a/src/GF/Speech/PrSRGS_ABNF.hs b/src/GF/Speech/PrSRGS_ABNF.hs
new file mode 100644
index 000000000..5549fb068
--- /dev/null
+++ b/src/GF/Speech/PrSRGS_ABNF.hs
@@ -0,0 +1,135 @@
+----------------------------------------------------------------------
+-- |
+-- Module      : PrJSRGS_ABNF
+-- Maintainer  : BB
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 2005/11/01 20:09:04 $ 
+-- > CVS $Author: bringert $
+-- > CVS $Revision: 1.16 $
+--
+-- This module prints a CFG as a JSGF grammar.
+--
+-- FIXME: remove \/ warn \/ fail if there are int \/ string literal
+-- categories in the grammar
+--
+-- FIXME: convert to UTF-8
+-----------------------------------------------------------------------------
+
+module GF.Speech.PrSRGS_ABNF (srgsAbnfPrinter) where
+
+import GF.Conversion.Types
+import GF.Data.Utilities
+import GF.Formalism.CFG
+import GF.Formalism.Utilities (Symbol(..), NameProfile(..), Profile(..), filterCats)
+import GF.Infra.Ident
+import GF.Infra.Print
+import GF.Infra.Option
+import GF.Probabilistic.Probabilistic (Probs)
+import GF.Speech.SISR
+import GF.Speech.SRG
+import GF.Speech.RegExp
+import GF.Compile.ShellState (StateGrammar)
+import GF.Today
+
+import Data.Char
+import Data.List
+import Text.PrettyPrint.HughesPJ
+import Debug.Trace
+
+
+srgsAbnfPrinter :: Maybe SISRFormat
+                -> Bool -- ^ Include probabilities
+	        -> Options 
+                -> StateGrammar -> String
+srgsAbnfPrinter sisr probs opts s = show $ prABNF sisr probs $ makeSimpleSRG opts s
+
+prABNF :: Maybe SISRFormat -> Bool -> SRG -> Doc
+prABNF sisr probs srg@(SRG{grammarName=name,grammarLanguage = l,
+                     startCat=start,origStartCat=origStart,rules=rs})
+    = header $++$ mainCat $++$ vcat topCatRules $++$ foldr ($++$) empty (map prRule rs)
+    where
+    header = text "#ABNF 1.0 UTF-8;" $$
+             meta "description" 
+               ("Speech recognition grammar for " ++ name
+                ++ ". " ++ "Original start category: " ++ origStart) $$
+             meta "generator" ("Grammatical Framework " ++ version) $$
+             text "language" <+> text l <> char ';'
+    mainCat = text "root" <+> prCat start <> char ';'
+    prRule (SRGRule cat origCat rhs) = 
+	comment origCat $$
+        rule False cat (map prAlt (ebnfSRGAlts rhs))
+    -- FIXME: use the probability
+    prAlt (EBnfSRGAlt mp n rhs) = sep [initTag, parens (prItem sisr n rhs), finalTag]
+      where initTag | isEmpty t = empty
+                    | otherwise = text "$NULL" <+>  t
+                where t = tag sisr (profileInitSISR n)
+            finalTag = tag sisr (profileFinalSISR n)
+
+    topCatRules = [rule True (catFormId tc) (map (it tc) cs) | (tc,cs) <- srgTopCats srg]
+        where it i c = prCat c <+> tag sisr (topCatSISR c)
+
+catFormId :: String -> String
+catFormId = (++ "_cat")
+
+prCat :: SRGCat -> Doc
+prCat c = char '$' <> text c
+
+prItem :: Maybe SISRFormat -> CFTerm -> EBnfSRGItem -> Doc
+prItem sisr t = f 1
+  where
+    f _ (REUnion [])  = text "$VOID"
+    f p (REUnion xs) 
+        | not (null es) = brackets (f 0 (REUnion nes))
+        | otherwise = (if p >= 1 then parens else id) (alts (map (f 1) xs))
+      where (es,nes) = partition isEpsilon xs
+    f _ (REConcat []) = text "$NULL"
+    f p (REConcat xs) = (if p >= 3 then parens else id) (hsep (map (f 2) xs))
+    f p (RERepeat x)  = f 3 x <> text "<0->"
+    f _ (RESymbol s)  = prSymbol sisr t s
+
+
+prSymbol :: Maybe SISRFormat -> CFTerm -> Symbol SRGNT Token -> Doc
+prSymbol sisr cn (Cat n@(c,_)) = prCat c <+> tag sisr (catSISR cn n)
+prSymbol _ cn (Tok t) | all isPunct (prt t) = empty  -- removes punctuation
+                      | otherwise = text (prt t) -- FIXME: quote if there is whitespace or odd chars
+
+tag :: Maybe SISRFormat -> (SISRFormat -> SISRTag) -> Doc
+tag Nothing _ = empty
+tag (Just fmt) t = 
+    case t fmt of
+      [] -> empty
+      -- grr, silly SRGS ABNF does not have an escaping mechanism
+      ts | '{' `elem` x || '}' `elem` x -> text "{!{" <+> text x <+> text "}!}"
+         | otherwise -> text "{" <+> text x <+> text "}"
+         where x = prSISR ts
+
+isPunct :: Char -> Bool
+isPunct c = c `elem` "-_.;.,?!"
+
+comment :: String -> Doc
+comment s = text "//" <+> text s
+
+alts :: [Doc] -> Doc
+alts = sep . prepunctuate (text "| ")
+
+rule :: Bool -> SRGCat -> [Doc] -> Doc
+rule pub c xs = sep [p <+> prCat c <+> char '=', nest 2 (alts xs) <+> char ';']
+  where p = if pub then text "public" else empty
+
+meta :: String -> String -> Doc
+meta n v = text "meta" <+> text (show n) <+> text "is" <+> text (show v)
+
+-- Pretty-printing utilities
+
+emptyLine :: Doc
+emptyLine = text ""
+
+prepunctuate :: Doc -> [Doc] -> [Doc]
+prepunctuate _ [] = []
+prepunctuate p (x:xs) = x : map (p <>) xs
+
+($++$) :: Doc -> Doc -> Doc
+x $++$ y = x $$ emptyLine $$ y
+
diff --git a/src/GF/UseGrammar/Custom.hs b/src/GF/UseGrammar/Custom.hs
index ca2b704b6..9ae9cd04a 100644
--- a/src/GF/UseGrammar/Custom.hs
+++ b/src/GF/UseGrammar/Custom.hs
@@ -61,7 +61,8 @@ import GF.Canon.MkGFC
 import GF.CF.CFtoSRG
 import GF.Speech.PrGSL (gslPrinter)
 import GF.Speech.PrJSGF (jsgfPrinter)
-import qualified GF.Speech.PrSRGS as SRGS
+import GF.Speech.PrSRGS
+import GF.Speech.PrSRGS_ABNF
 import qualified GF.Speech.SISR as SISR
 import GF.Speech.PrSLF
 import GF.Speech.PrFA (faGraphvizPrinter,regularPrinter,faCPrinter)
@@ -251,9 +252,11 @@ customGrammarPrinter =
   ,(strCI "gsl",     gslPrinter)
   ,(strCI "jsgf",    jsgfPrinter Nothing)
   ,(strCI "jsgf_sisr_old", jsgfPrinter (Just SISR.SISROld))
-  ,(strCI "srgs_xml", SRGS.srgsXmlPrinter Nothing False)
-  ,(strCI "srgs_xml_prob", SRGS.srgsXmlPrinter Nothing True)
-  ,(strCI "srgs_xml_sisr_old", SRGS.srgsXmlPrinter (Just SISR.SISROld) False)
+  ,(strCI "srgs_xml",           srgsXmlPrinter Nothing False)
+  ,(strCI "srgs_xml_prob",      srgsXmlPrinter Nothing True)
+  ,(strCI "srgs_xml_sisr_old",  srgsXmlPrinter (Just SISR.SISROld) False)
+  ,(strCI "srgs_abnf",          srgsAbnfPrinter Nothing False)
+  ,(strCI "srgs_abnf_sisr_old", srgsAbnfPrinter (Just SISR.SISROld) False)
   ,(strCI "vxml", grammar2vxml)
   ,(strCI "slf",  slfPrinter)
   ,(strCI "slf_graphviz", slfGraphvizPrinter)