Add function to search for reserved operators.

src/reserved.c

@@ -0,0 +1,21 @@
+#include "reserved.h"
+#include "string.h"
+
+static const libab_reserved_operator libab_reserved_operators[] = {
+    {
+        "=", /* Assignment */
+        0, /* Lowest precedence */
+        1 /* Right associative, a = b = 6 should be a = (b = 6) */
+    }
+};
+
+const libab_reserved_operator* libab_find_reserved_operator(const char* name) {
+    static const size_t element_count = 
+        sizeof(libab_reserved_operators) / sizeof(libab_reserved_operator);
+    size_t i;
+    for(i = 0; i < element_count; i++) {
+        if(strcmp(name, libab_reserved_operators[i].op) == 0)
+            return &libab_reserved_operators[i];
+    }
+    return NULL;
+}