it does addition

1 files changed, 9 insertions, 0 deletions

diff --git a/expr.h b/expr.h
index e69de29..4b4a874 100644
--- a/expr.h
+++ b/expr.h
@@ -0,0 +1,9 @@
+typedef struct {
+	int type;
+	union {
+		int i;
+		char *s;
+	} u;
+} expr_yystype;
+
+#define YYSTYPE expr_yystype