Printing to LBNF.

src/GF/CF/PrLBNF.hs

@@ -0,0 +1,53 @@
+module PrLBNF (prLBNF) where
+
+import CF
+import CFIdent
+import AbsGFC
+import Ident
+import PrGrammar
+
+import Operations
+import Char
+
+-- Printing CF grammars generated from GF as LBNF grammar for BNFC.
+-- AR 26/1/2000 -- 9/6/2003 (PPrCF) -- 8/11/2003
+-- With a primitive error messaging, by rules and rule tails commented out
+
+prLBNF :: CF -> String
+prLBNF = unlines . (map prCFRule) . rulesOfCF -- hiding the literal recogn function
+
+prCFRule :: CFRule -> String
+prCFRule (fun,(cat,its)) = 
+  prCFFun fun ++ "." +++ prCFCat True cat +++ "::=" +++  --- err in cat -> in syntax
+  unwords (map prCFItem its) +++ ";"
+
+prCFFun :: CFFun -> String
+prCFFun (CFFun (t, p)) = case t of
+  AC (CIQ _ x) -> prId True x
+  AD (CIQ _ x) -> prId True x
+  _ -> prErr True $ prt t
+   
+prId b i = case i of
+     IC "Int" -> "Integer"
+     IC s@(c:_) | isUpper c -> s ++ if isDigit (last s) then "_" else ""
+     _ -> prErr b $ prt i
+
+prLab i = case i of
+     L (IC "s") -> "" ---
+     _ -> "_" ++ prt i
+
+-- just comment out the rest if you cannot interpret the function name in LBNF
+-- two versions, depending on whether in the beginning of a rule or elsewhere;
+-- in the latter case, error just terminates the rule 
+prErr :: Bool -> String -> String
+prErr b s = (if b then "" else " ;") +++ "---" +++ s
+
+prCFCat :: Bool -> CFCat -> String
+prCFCat b (CFCat ((CIQ _ c),l)) = prId b c ++ prLab l ----
+
+prCFItem (CFNonterm c) = prCFCat False c
+prCFItem (CFTerm a) = prRegExp a
+
+prRegExp (RegAlts tt) = case tt of
+  [t] -> prQuotedString t
+  _ -> prErr False $ prParenth (prTList " | " (map prQuotedString tt))