Switch indices in strings to size_t.

include/eval.h

@@ -1,6 +1,7 @@
 #ifndef LIBLEX_EVAL_H
 #define LIBLEX_EVAL_H
 
+#include <stddef.h>
 #include "pattern.h"
 #include "pairmap.h"
 #include "ll.h"
@@ -11,8 +12,8 @@
  * are used to represent "matched" hypohteses.
  */
 struct match_s {
-  int from;
-  int to;
+  size_t from;
+  size_t to;
   int pattern;
 };
 
@@ -28,11 +29,11 @@ struct eval_s {
   /**
    * The current index in the input.
    */
-  int index;
+  size_t index;
   /**
    * The index where the valuation began.
    */
-  int begin;
+  size_t begin;
   /**
    * The number of nodes / states matched in
    * the last iteration.
@@ -104,7 +105,7 @@ liblex_result eval_config_add(eval_config* config, char* pattern, int pattern_id
  * @param match pointer to where to store the newly created match.
  * @return LIBLEX_SUCCESS if all goes well, or LIBLEX_MALLOC if there was an allocation failure.
  */
-liblex_result eval_word(char* string, int index, eval_config* config, match* match);
+liblex_result eval_word(char* string, size_t index, eval_config* config, match* match);
 /**
  * Evaluates input starting at the index until it reaches the null terminator,
  * adding the best matches to the linked list.
@@ -114,7 +115,7 @@ liblex_result eval_word(char* string, int index, eval_config* config, match* mat
  * @param matches the linked list to populate with matches
  * @return LIBLEX_SUCCESS if all goes well, or LIBLEX_MALLOC if there was an allocation failure.
  */
-liblex_result eval_all(char* string, int index, eval_config* config, ll* matches);
+liblex_result eval_all(char* string, size_t index, eval_config* config, ll* matches);
 /**
  * Function intended to be passed to "foreach" calls in libds.
  * Since eval_all creates a lot of matches and puts them all in a linked list,