Reimplement a lexer in C for the C bindings not to depend on GF.Text.Lexing for now.

contrib/c-bindings/PGFFFI.hs

@@ -1,5 +1,5 @@
 -- GF C Bindings
--- Copyright (C) 2008-2009 Kevin Kofler
+-- Copyright (C) 2008-2010 Kevin Kofler
 --
 -- This library is free software; you can redistribute it and/or
 -- modify it under the terms of the GNU Lesser General Public
@@ -24,7 +24,7 @@ import Foreign.C.Types
 import Control.Exception
 import IO
 import Data.Maybe
-import GF.Text.Lexing
+-- import GF.Text.Lexing
 
 
 -- Utility functions used in the implementation (not exported):
@@ -217,13 +217,13 @@ gf_parse pgf lang cat input = do
 
 -- GF.Text.Lexing:
 
-foreign export ccall gf_stringOp :: CString -> CString -> IO CString
+-- foreign export ccall gf_stringOp :: CString -> CString -> IO CString
-gf_stringOp op str = do
+-- gf_stringOp op str = do
-  o <- (peekCString op)
+--   o <- (peekCString op)
-  s <- (peekCString str)
+--   s <- (peekCString str)
-  case (stringOp o) of
+--   case (stringOp o) of
-    Just fn -> (newCString (fn s))
+--     Just fn -> (newCString (fn s))
-    Nothing -> (return nullPtr)
+--     Nothing -> (return nullPtr)
 
 
 -- Unused (exception handling):

contrib/c-bindings/build-gfctest.sh

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 # GF C Bindings
-# Copyright (C) 2008-2009 Kevin Kofler
+# Copyright (C) 2008-2010 Kevin Kofler
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -17,4 +17,4 @@
 # License along with this library; if not, see <http://www.gnu.org/licenses/>.
 
 ghc --make -fglasgow-exts -O2 -no-hs-main $* -c PGFFFI.hs &&
-ghc --make -fglasgow-exts -O2 -no-hs-main $* gfctest.c PGFFFI.hs -o gfctest
+ghc --make -fglasgow-exts -O2 -no-hs-main $* gfctest.c gf_lexing.c PGFFFI.hs -o gfctest

contrib/c-bindings/gfctest.c

@@ -18,6 +18,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include "pgf.h"
+#include "gf_lexing.h"
 
 int main(int argc, char *argv[])
 {
@@ -26,7 +27,7 @@ int main(int argc, char *argv[])
   GF_PGF pgf = gf_readPGF("../examples/tutorial/embedded/Query.pgf");
   GF_Language lang = gf_readLanguage("QueryEng");
   GF_Type cat = gf_startCat(pgf);
-  char *lexed = gf_stringOp("lextext", "Is 2 prime");
+  char *lexed = gf_stringOp("lextext")("Is 2 prime");
   GF_Tree *result = gf_parse(pgf, lang, cat, lexed);
   free(lexed);
   GF_Tree *p = result;

contrib/c-bindings/readme-ffi.txt

@@ -1,5 +1,5 @@
 GF C Bindings
-Copyright (C) 2008-2009 Kevin Kofler
+Copyright (C) 2008-2010 Kevin Kofler
 
 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
@@ -109,10 +109,12 @@ void gf_freeTrees(GF_Tree *p);
 
 
 
-In addition, the following function from GF.Text.Lexing:
+In addition, a C equivalent to the following function from GF.Text.Lexing:
 stringOp :: String -> Maybe (String -> String)
-is wrapped as:
+is provided as:
-char *gf_stringOp(char *op, char *str)
+typedef char *(*GF_StringOp)(const char *str);
-which returns NULL if op is not a valid operation name, otherwise applies the
+GF_StringOp gf_stringOp(const char *op); /* may return NULL */
-function corresponding to op to the string str. The resulting string must be
+which returns NULL if op is not a valid operation name, otherwise a pointer to a
-freed with free if non-NULL.
+function which applies the function corresponding to op to the string str. The
+resulting string must be freed with free. The function pointer MUST NOT be
+freed.