Add a utility header to convert error codes.

include/libabacus.h

@@ -7,7 +7,9 @@
  */
 enum libab_result {
     LIBAB_SUCCESS,
-    LIBAB_MALLOC
+    LIBAB_MALLOC,
+    LIBAB_BAD_PATTERN,
+    LIBAB_FAILED_MATCH
 };
 
 typedef enum libab_result libab_result;

include/libabacus_util.h

@@ -0,0 +1,21 @@
+#ifndef LIBABACUS_UTIL_H
+#define LIBABACUS_UTIL_H
+
+#include "libds.h"
+#include "liblex.h"
+#include "libabacus.h"
+
+/**
+ * Converts a result code from liblex to libabacus.
+ * @param to_convert the code to convert.
+ * @return the libabacus equivalent of the error code.
+ */
+libab_result convert_lex_result(liblex_result to_convert);
+/**
+ * Converts a result code from libds to libabacus.
+ * @param to_convert the code to convert.
+ * @return the libabacus equivalent of the error code.
+ */
+libab_result convert_ds_result(libds_result to_convert);
+
+#endif