diff --git a/Makefile b/Makefile
index 66edd15..e492595 100644
--- a/Makefile
+++ b/Makefile
@@ -29,9 +29,18 @@ grammar : .FORCE
 	./greg -o greg.c greg.g
 
 clean : .FORCE
-	rm -f *~ *.o *.greg.[cd]
+	rm -rf *~ *.o *.greg.[cd] greg samples/*.o samples/calc samples/calc.dSYM
 
 spotless : clean .FORCE
 	rm -f greg
 
+samples/calc.c: samples/calc.leg greg
+	./greg -o $@ $<
+
+samples/calc: samples/calc.c
+	$(CC) $(CFLAGS) -o $@ $<
+
+test: samples/calc
+	echo '21 * 2 + 0' | ./samples/calc | grep 42
+
 .FORCE :
diff --git a/compile.c b/compile.c
index a04e2b0..77ca3c6 100644
--- a/compile.c
+++ b/compile.c
@@ -382,7 +382,7 @@ static char *preamble= "\
 #define YY_NAME(N) yy##N\n\
 #endif\n\
 #ifndef YY_INPUT\n\
-#define YY_INPUT(buf, result, max_size)                 \\\n\
+#define YY_INPUT(buf, result, max_size, D)              \\\n\
   {                                                     \\\n\
     int yyc= getchar();                                 \\\n\
     result= (EOF == yyc) ? 0 : (*(buf)= yyc, 1);        \\\n\
@@ -449,13 +449,12 @@ typedef struct _GREG {\n\
 YY_LOCAL(int) yyrefill(GREG *G)\n\
 {\n\
   int yyn;\n\
-  YY_XTYPE YY_XVAR = (YY_XTYPE) G->data;\n\
   while (G->buflen - G->pos < 512)\n\
     {\n\
       G->buflen *= 2;\n\
-      G->buf= YY_REALLOC(G->buf, G->buflen, G->data);\n\
+      G->buf= (char*)YY_REALLOC(G->buf, G->buflen, G->data);\n\
     }\n\
-  YY_INPUT((G->buf + G->pos), yyn, (G->buflen - G->pos));\n\
+  YY_INPUT((G->buf + G->pos), yyn, (G->buflen - G->pos), G->data);\n\
   if (!yyn) return 0;\n\
   G->limit += yyn;\n\
   return 1;\n\
@@ -481,7 +480,7 @@ YY_LOCAL(int) yymatchChar(GREG *G, int c)\n\
   return 0;\n\
 }\n\
 \n\
-YY_LOCAL(int) yymatchString(GREG *G, char *s)\n\
+YY_LOCAL(int) yymatchString(GREG *G, const char *s)\n\
 {\n\
   int yysav= G->pos;\n\
   while (*s)\n\
@@ -518,7 +517,7 @@ YY_LOCAL(void) yyDo(GREG *G, yyaction action, int begin, int end)\n\
   while (G->thunkpos >= G->thunkslen)\n\
     {\n\
       G->thunkslen *= 2;\n\
-      G->thunks= YY_REALLOC(G->thunks, sizeof(yythunk) * G->thunkslen, G->data);\n\
+      G->thunks= (yythunk*)YY_REALLOC(G->thunks, sizeof(yythunk) * G->thunkslen, G->data);\n\
     }\n\
   G->thunks[G->thunkpos].begin=  begin;\n\
   G->thunks[G->thunkpos].end=    end;\n\
@@ -536,7 +535,7 @@ YY_LOCAL(int) yyText(GREG *G, int begin, int end)\n\
       while (G->textlen < (yyleng - 1))\n\
         {\n\
           G->textlen *= 2;\n\
-          G->text= YY_REALLOC(G->text, G->textlen, G->data);\n\
+          G->text= (char*)YY_REALLOC(G->text, G->textlen, G->data);\n\
         }\n\
       memcpy(G->text, G->buf + begin, yyleng);\n\
     }\n\
@@ -606,13 +605,13 @@ YY_PARSE(int) YY_NAME(parse_from)(GREG *G, yyrule yystart)\n\
   if (!G->buflen)\n\
     {\n\
       G->buflen= YY_BUFFER_START_SIZE;\n\
-      G->buf= YY_ALLOC(G->buflen, G->data);\n\
+      G->buf= (char*)YY_ALLOC(G->buflen, G->data);\n\
       G->textlen= YY_BUFFER_START_SIZE;\n\
-      G->text= YY_ALLOC(G->textlen, G->data);\n\
+      G->text= (char*)YY_ALLOC(G->textlen, G->data);\n\
       G->thunkslen= YY_STACK_SIZE;\n\
-      G->thunks= YY_ALLOC(sizeof(yythunk) * G->thunkslen, G->data);\n\
+      G->thunks= (yythunk*)YY_ALLOC(sizeof(yythunk) * G->thunkslen, G->data);\n\
       G->valslen= YY_STACK_SIZE;\n\
-      G->vals= YY_ALLOC(sizeof(YYSTYPE) * G->valslen, G->data);\n\
+      G->vals= (YYSTYPE*)YY_ALLOC(sizeof(YYSTYPE) * G->valslen, G->data);\n\
       G->begin= G->end= G->pos= G->limit= G->thunkpos= 0;\n\
     }\n\
   G->pos = 0;\n\
@@ -643,6 +642,17 @@ YY_PARSE(int) YY_NAME(parse)(GREG *G)\n\
   return YY_NAME(parse_from)(G, yy_%s);\n\
 }\n\
 \n\
+YY_PARSE(void) YY_NAME(init)(GREG *G)\n\
+{\n\
+    memset(G, 0, sizeof(GREG));\n\
+}\n\
+YY_PARSE(void) YY_NAME(deinit)(GREG *G)\n\
+{\n\
+    if (G->buf) YY_FREE(G->buf);\n\
+    if (G->text) YY_FREE(G->text);\n\
+    if (G->thunks) YY_FREE(G->thunks);\n\
+    if (G->vals) YY_FREE(G->vals);\n\
+}\n\
 YY_PARSE(GREG *) YY_NAME(parse_new)(YY_XTYPE data)\n\
 {\n\
   GREG *G = (GREG *)YY_CALLOC(1, sizeof(GREG), G->data);\n\
@@ -652,6 +662,7 @@ YY_PARSE(GREG *) YY_NAME(parse_new)(YY_XTYPE data)\n\
 \n\
 YY_PARSE(void) YY_NAME(parse_free)(GREG *G)\n\
 {\n\
+  YY_NAME(deinit)(G);\n\
   YY_FREE(G);\n\
 }\n\
 \n\
diff --git a/greg.c b/greg.c
index 2353184..dab8815 100644
--- a/greg.c
+++ b/greg.c
@@ -36,7 +36,7 @@ struct _GREG;
 
   void yyerror(struct _GREG *, char *message);
 
-# define YY_INPUT(buf, result, max)		\
+# define YY_INPUT(buf, result, max, D)		\
   {						\
     int c= getc(input);				\
     if ('\n' == c || '\r' == c) ++lineNumber;	\
@@ -74,7 +74,7 @@ struct _GREG;
 #define YY_NAME(N) yy##N
 #endif
 #ifndef YY_INPUT
-#define YY_INPUT(buf, result, max_size)                 \
+#define YY_INPUT(buf, result, max_size, D)              \
   {                                                     \
     int yyc= getchar();                                 \
     result= (EOF == yyc) ? 0 : (*(buf)= yyc, 1);        \
@@ -141,13 +141,12 @@ typedef struct _GREG {
 YY_LOCAL(int) yyrefill(GREG *G)
 {
   int yyn;
-  YY_XTYPE YY_XVAR = (YY_XTYPE) G->data;
   while (G->buflen - G->pos < 512)
     {
       G->buflen *= 2;
-      G->buf= YY_REALLOC(G->buf, G->buflen, G->data);
+      G->buf= (char*)YY_REALLOC(G->buf, G->buflen, G->data);
     }
-  YY_INPUT((G->buf + G->pos), yyn, (G->buflen - G->pos));
+  YY_INPUT((G->buf + G->pos), yyn, (G->buflen - G->pos), G->data);
   if (!yyn) return 0;
   G->limit += yyn;
   return 1;
@@ -173,7 +172,7 @@ YY_LOCAL(int) yymatchChar(GREG *G, int c)
   return 0;
 }
 
-YY_LOCAL(int) yymatchString(GREG *G, char *s)
+YY_LOCAL(int) yymatchString(GREG *G, const char *s)
 {
   int yysav= G->pos;
   while (*s)
@@ -210,7 +209,7 @@ YY_LOCAL(void) yyDo(GREG *G, yyaction action, int begin, int end)
   while (G->thunkpos >= G->thunkslen)
     {
       G->thunkslen *= 2;
-      G->thunks= YY_REALLOC(G->thunks, sizeof(yythunk) * G->thunkslen, G->data);
+      G->thunks= (yythunk*)YY_REALLOC(G->thunks, sizeof(yythunk) * G->thunkslen, G->data);
     }
   G->thunks[G->thunkpos].begin=  begin;
   G->thunks[G->thunkpos].end=    end;
@@ -228,7 +227,7 @@ YY_LOCAL(int) yyText(GREG *G, int begin, int end)
       while (G->textlen < (yyleng - 1))
         {
           G->textlen *= 2;
-          G->text= YY_REALLOC(G->text, G->textlen, G->data);
+          G->text= (char*)YY_REALLOC(G->text, G->textlen, G->data);
         }
       memcpy(G->text, G->buf + begin, yyleng);
     }
@@ -946,13 +945,13 @@ YY_PARSE(int) YY_NAME(parse_from)(GREG *G, yyrule yystart)
   if (!G->buflen)
     {
       G->buflen= YY_BUFFER_START_SIZE;
-      G->buf= YY_ALLOC(G->buflen, G->data);
+      G->buf= (char*)YY_ALLOC(G->buflen, G->data);
       G->textlen= YY_BUFFER_START_SIZE;
-      G->text= YY_ALLOC(G->textlen, G->data);
+      G->text= (char*)YY_ALLOC(G->textlen, G->data);
       G->thunkslen= YY_STACK_SIZE;
-      G->thunks= YY_ALLOC(sizeof(yythunk) * G->thunkslen, G->data);
+      G->thunks= (yythunk*)YY_ALLOC(sizeof(yythunk) * G->thunkslen, G->data);
       G->valslen= YY_STACK_SIZE;
-      G->vals= YY_ALLOC(sizeof(YYSTYPE) * G->valslen, G->data);
+      G->vals= (YYSTYPE*)YY_ALLOC(sizeof(YYSTYPE) * G->valslen, G->data);
       G->begin= G->end= G->pos= G->limit= G->thunkpos= 0;
     }
   G->pos = 0;
@@ -983,6 +982,17 @@ YY_PARSE(int) YY_NAME(parse)(GREG *G)
   return YY_NAME(parse_from)(G, yy_grammar);
 }
 
+YY_PARSE(void) YY_NAME(init)(GREG *G)
+{
+    memset(G, 0, sizeof(GREG));
+}
+YY_PARSE(void) YY_NAME(deinit)(GREG *G)
+{
+    if (G->buf) YY_FREE(G->buf);
+    if (G->text) YY_FREE(G->text);
+    if (G->thunks) YY_FREE(G->thunks);
+    if (G->vals) YY_FREE(G->vals);
+}
 YY_PARSE(GREG *) YY_NAME(parse_new)(YY_XTYPE data)
 {
   GREG *G = (GREG *)YY_CALLOC(1, sizeof(GREG), G->data);
@@ -992,6 +1002,7 @@ YY_PARSE(GREG *) YY_NAME(parse_new)(YY_XTYPE data)
 
 YY_PARSE(void) YY_NAME(parse_free)(GREG *G)
 {
+  YY_NAME(deinit)(G);
   YY_FREE(G);
 }
 
diff --git a/greg.g b/greg.g
index 558e9ae..02332e1 100644
--- a/greg.g
+++ b/greg.g
@@ -48,7 +48,7 @@
 
   void yyerror(struct _GREG *, char *message);
 
-# define YY_INPUT(buf, result, max)		\
+# define YY_INPUT(buf, result, max, D)		\
   {						\
     int c= getc(input);				\
     if ('\n' == c || '\r' == c) ++lineNumber;	\
diff --git a/samples/calc.leg b/samples/calc.leg
index 0dd91ed..370b288 100644
--- a/samples/calc.leg
+++ b/samples/calc.leg
@@ -41,8 +41,9 @@ EOL     = '\n' | '\r\n' | '\r' | ';'
 int main()
 {
   GREG g;
-  memset(&g, 0, sizeof(GREG));
+  yyinit(&g);
   while (yyparse(&g));
+  yydeinit(&g);
 
   return 0;
 }