Initial import

util.h

@@ -0,0 +1,28 @@
+#include <lua.h>
+
+#define LFAIL_RET 2
+
+#define newoverride(L, lib, libname)                \
+	lua_getglobal(L, libname);                      \
+	for (int i = 0; lib[i].name != NULL; i++) {     \
+		lua_pushcfunction(L, lib[i].func);          \
+		lua_setfield(L, -2, lib[i].name);           \
+	}
+
+/*
+ * Pushes the fail value and the string mesg
+ * onto the stack, then returns 2.
+ */
+int lfail(lua_State *L, const char* mesg);
+/*
+ * Prepends t onto s.
+ * Assumes s has enough space allocated
+ * for the combined string.
+ */
+void strprepend(char* s, const char* t);
+
+/*
+ * Slices the string s into buf.
+ * The sliced string has the range [start .. end].
+ */
+void strslice(const char *s, char *buf, size_t start, size_t end);