Fix issue #146 in C and C++.

Do some refactoring to remove some related duplication.
BNFC · Jun 24, 2015 · 9402769 · 9402769
1 parent 316e5ed
commit 9402769
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diff --git a/source/src/BNFC/Backend/C/CFtoFlexC.hs b/source/src/BNFC/Backend/C/CFtoFlexC.hs
@@ -35,11 +35,15 @@
 
    **************************************************************
 -}
-module BNFC.Backend.C.CFtoFlexC (cf2flex) where
+module BNFC.Backend.C.CFtoFlexC (cf2flex, lexComments, cMacros) where
+
+import Data.Maybe (fromMaybe)
 
 import BNFC.CF
 import BNFC.Backend.CPP.NoSTL.RegToFlex
 import BNFC.Backend.Common.NamedVariables
+import BNFC.PrettyPrint
+import BNFC.Utils (cstring)
 
 --The environment must be returned for the parser to use.
 cf2flex :: String -> CF -> (String, SymEnv)
@@ -85,8 +89,8 @@ prelude name = unlines
    "%}"
   ]
 
---For now all categories are included.
---Optimally only the ones that are used should be generated.
+-- For now all categories are included.
+-- Optimally only the ones that are used should be generated.
 cMacros :: String
 cMacros = unlines
   [
@@ -110,7 +114,7 @@ lexSymbols ss = concatMap transSym ss
 restOfFlex :: CF -> SymEnv -> String
 restOfFlex cf env = concat
   [
-   lexComments (comments cf),
+   render $ lexComments Nothing (comments cf),
    userDefTokens,
    ifC catString  strStates,
    ifC catChar    chStates,
@@ -157,26 +161,92 @@ restOfFlex cf env = concat
     ]
    footer = "void initialize_lexer(FILE *inp) { yyrestart(inp); BEGIN YYINITIAL; }"
 
-lexComments :: ([(String, String)], [String]) -> String
-lexComments (m,s) =
-  (unlines (map lexSingleComment s))
-  ++ (unlines (map lexMultiComment m))
-
-lexSingleComment :: String -> String
-lexSingleComment c =
-  "<YYINITIAL>\"" ++ c ++ "\"[^\\n]*\\n     ++yy_mylinenumber; \t /* BNFC single-line comment */;"
-
---There might be a possible bug here if a language includes 2 multi-line comments.
---They could possibly start a comment with one character and end it with another.
---However this seems rare.
-lexMultiComment :: (String, String) -> String
-lexMultiComment (b,e) = unlines [
-  "<YYINITIAL>\"" ++ b ++ "\"      \t BEGIN COMMENT;",
-  "<COMMENT>\"" ++ e ++ "\"      \t BEGIN YYINITIAL;",
-  "<COMMENT>.      \t /* BNFC multi-line comment */;",
-  "<COMMENT>[\\n]    ++yy_mylinenumber ; \t /* BNFC multi-line comment */;"
-  ]
+-- ---------------------------------------------------------------------------
+-- Comments
+
+-- | Create flex rules for single-line and multi-lines comments.
+-- The first argument is an optional namespace (for C++); the second
+-- argument is the set of comment delimiters as returned by BNFC.CF.comments.
+--
+-- This function is only compiling the results of applying either
+-- lexSingleComment or lexMultiComment on each comment delimiter or pair of
+-- delimiters.
+--
+-- >>> lexComments (Just "myns.") ([("{-","-}")],["--"])
+-- <YYINITIAL>"--"[^\n]*\n ++myns.yy_mylinenumber; // BNFC: comment "--";
+-- <YYINITIAL>"{-" BEGIN COMMENT; // BNFC: comment "{-" "-}";
+-- <COMMENT>"-}" BEGIN YYINITIAL;
+-- <COMMENT>. /* skip */;
+-- <COMMENT>[\n] ++myns.yy_mylinenumber;
+lexComments :: Maybe String -> ([(String, String)], [String]) -> Doc
+lexComments ns (m,s) =
+    vcat (map (lexSingleComment ns) s ++ map (lexMultiComment ns) m)
+
+-- | Create a lexer rule for single-line comments.
+-- The first argument is -- an optional c++ namespace
+-- The second argument is the delimiter that marks the beginning of the
+-- comment.
+--
+-- >>> lexSingleComment (Just "mypackage.") "--"
+-- <YYINITIAL>"--"[^\n]*\n ++mypackage.yy_mylinenumber; // BNFC: comment "--";
+--
+-- >>> lexSingleComment Nothing "--"
+-- <YYINITIAL>"--"[^\n]*\n ++yy_mylinenumber; // BNFC: comment "--";
+--
+-- >>> lexSingleComment Nothing "\""
+-- <YYINITIAL>"\""[^\n]*\n ++yy_mylinenumber; // BNFC: comment "\"";
+lexSingleComment :: Maybe String -> String -> Doc
+lexSingleComment ns c =
+    "<YYINITIAL>" <> cstring c <> "[^\\n]*\\n"
+    <+> "++"<> text (fromMaybe "" ns)<>"yy_mylinenumber;"
+    <+> "// BNFC: comment" <+> cstring c <> ";"
+
+-- | Create a lexer rule for multi-lines comments.
+-- The first argument is -- an optional c++ namespace
+-- The second arguments is the pair of delimiter for the multi-lines comment:
+-- start deleminiter and end delimiter.
+-- There might be a possible bug here if a language includes 2 multi-line
+-- comments. They could possibly start a comment with one character and end it
+-- with another.  However this seems rare.
+--
+-- >>> lexMultiComment Nothing ("{-", "-}")
+-- <YYINITIAL>"{-" BEGIN COMMENT; // BNFC: comment "{-" "-}";
+-- <COMMENT>"-}" BEGIN YYINITIAL;
+-- <COMMENT>. /* skip */;
+-- <COMMENT>[\n] ++yy_mylinenumber;
+--
+-- >>> lexMultiComment (Just "foo.") ("{-", "-}")
+-- <YYINITIAL>"{-" BEGIN COMMENT; // BNFC: comment "{-" "-}";
+-- <COMMENT>"-}" BEGIN YYINITIAL;
+-- <COMMENT>. /* skip */;
+-- <COMMENT>[\n] ++foo.yy_mylinenumber;
+--
+-- >>> lexMultiComment Nothing ("\"'", "'\"")
+-- <YYINITIAL>"\"'" BEGIN COMMENT; // BNFC: comment "\"'" "'\"";
+-- <COMMENT>"'\"" BEGIN YYINITIAL;
+-- <COMMENT>. /* skip */;
+-- <COMMENT>[\n] ++yy_mylinenumber;
+lexMultiComment :: Maybe String -> (String, String) -> Doc
+lexMultiComment ns (b,e) = vcat
+    [ "<YYINITIAL>" <> cstring b <+> "BEGIN COMMENT;"
+        <+> "// BNFC: comment" <+> cstring b <+> cstring e <> ";"
+    , "<COMMENT>" <> cstring e <+> "BEGIN YYINITIAL;"
+    , "<COMMENT>. /* skip */;"
+    , "<COMMENT>[\\n] ++"<> text (fromMaybe "" ns) <>"yy_mylinenumber;"
+    ]
 
+-- --There might be a possible bug here if a language includes 2 multi-line comments.
+-- --They could possibly start a comment with one character and end it with another.
+-- --However this seems rare.
+-- --
+-- lexMultiComment :: Maybe String -> (String, String) -> String
+-- lexMultiComment inPackage (b,e) = unlines [
+--   "<YYINITIAL>\"" ++ b ++ "\"      \t BEGIN COMMENT;",
+--   "<COMMENT>\"" ++ e ++ "\"      \t BEGIN YYINITIAL;",
+--   "<COMMENT>.      \t /* BNFC multi-line comment */;",
+--   "<COMMENT>[\\n]   ++" ++ nsString inPackage ++ "yy_mylinenumber ; \t /* BNFC multi-line comment */;"
+--  ---- "\\n  ++yy_mylinenumber ;"
+--   ]
 --Helper function that escapes characters in strings
 escapeChars :: String -> String
 escapeChars [] = []

diff --git a/source/src/BNFC/Backend/CPP/NoSTL/CFtoFlex.hs b/source/src/BNFC/Backend/CPP/NoSTL/CFtoFlex.hs
@@ -38,9 +38,11 @@
 module BNFC.Backend.CPP.NoSTL.CFtoFlex (cf2flex) where
 
 import BNFC.CF
+import BNFC.Backend.C.CFtoFlexC (lexComments, cMacros)
 import BNFC.Backend.CPP.NoSTL.RegToFlex
 import BNFC.Backend.Common.NamedVariables
 import BNFC.Backend.CPP.STL.STLUtils
+import BNFC.PrettyPrint
 
 --The environment must be returned for the parser to use.
 cf2flex :: Maybe String -> String -> CF -> (String, SymEnv)
@@ -81,20 +83,6 @@ prelude inPackage _ = unlines
    "%}"
   ]
 
---For now all categories are included.
---Optimally only the ones that are used should be generated.
-cMacros :: String
-cMacros = unlines
-  [
-  "LETTER [a-zA-Z]",
-  "CAPITAL [A-Z]",
-  "SMALL [a-z]",
-  "DIGIT [0-9]",
-  "IDENT [a-zA-Z0-9'_]",
-  "%START YYINITIAL COMMENT CHAR CHARESC CHAREND STRING ESCAPED",
-  "%%"
-  ]
-
 lexSymbols :: SymEnv -> String
 lexSymbols ss = concatMap transSym ss
   where
@@ -106,7 +94,7 @@ lexSymbols ss = concatMap transSym ss
 restOfFlex :: Maybe String -> CF -> SymEnv -> String
 restOfFlex inPackage cf env = concat
   [
-   lexComments inPackage (comments cf),
+   render $ lexComments inPackage (comments cf),
    userDefTokens,
    ifC catString strStates,
    ifC catChar chStates,
@@ -159,28 +147,6 @@ restOfFlex inPackage cf env = concat
     ]
 
 
-lexComments :: Maybe String -> ([(String, String)], [String]) -> String
-lexComments inPackage (m,s) =
-  (unlines (map (lexSingleComment inPackage) s))
-  ++ (unlines (map (lexMultiComment inPackage) m))
-
-lexSingleComment :: Maybe String -> String -> String
-lexSingleComment inPackage c =
-  "<YYINITIAL>\"" ++ c ++ "\"[^\\n]*\\n  ++" ++ nsString inPackage ++ "yy_mylinenumber ; \t /* BNFC single-line comment */;"
-
---There might be a possible bug here if a language includes 2 multi-line comments.
---They could possibly start a comment with one character and end it with another.
---However this seems rare.
-lexMultiComment :: Maybe String -> (String, String) -> String
-lexMultiComment inPackage (b,e) = unlines [
-  "<YYINITIAL>\"" ++ b ++ "\"      \t BEGIN COMMENT;",
-  "<COMMENT>\"" ++ e ++ "\"      \t BEGIN YYINITIAL;",
-  "<COMMENT>.      \t /* BNFC multi-line comment */;",
-  "<COMMENT>[\\n]   ++" ++ nsString inPackage ++ "yy_mylinenumber ; \t /* BNFC multi-line comment */;"
- ---- "\\n  ++yy_mylinenumber ;"
-  ]
-
-
 --Helper function that escapes characters in strings
 escapeChars :: String -> String
 escapeChars [] = []

diff --git a/source/src/BNFC/Utils.hs b/source/src/BNFC/Utils.hs
@@ -23,6 +23,7 @@ module BNFC.Utils
     , lowerCase, upperCase, mixedCase, camelCase, snakeCase
     , replace, prParenth
     , writeFileRep
+    , cstring
     ) where
 
 import Control.Arrow ((&&&))
@@ -237,3 +238,14 @@ mixedCase = text . mkName [] MixedCase
 -- my_ident
 snakeCase :: String -> Doc
 snakeCase = text . mkName [] SnakeCase
+
+-- ESCAPING
+
+-- | a function that renders a c-like string with escaped characters:
+-- >>> cstring "foobar"
+-- "foobar"
+--
+-- >>> cstring "foobar\""
+-- "foobar\""
+cstring :: String -> Doc
+cstring = text . show