Store information about tokens when they are added.

include/eval.h

@@ -74,9 +74,26 @@ struct eval_config_s {
   ll states;
 };
 
+/**
+ * Information about a state that has been
+ * added with eval_config_add.
+ */
+struct eval_state_s {
+  /**
+   * The string that was used to compile
+   * this state.
+   */
+  const char* source;
+  /**
+   * The pattern that was generated with this state.
+   */
+  pattern* pattern;
+};
+
 typedef struct match_s match;
 typedef struct eval_s eval;
 typedef struct eval_config_s eval_config;
+typedef struct eval_state_s eval_state;
 
 /**
  * Initializes the evaluation configuration.