From 600f169b5bd2ccd8eaf36d2692597ad829060e76 Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Thu, 20 Jul 2017 22:09:42 -0700
Subject: [PATCH] Use const variables in eval as much as possible.

---
 include/eval.h |  8 ++++----
 src/eval.c     | 10 +++++-----
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/eval.h b/include/eval.h
index 31d9bc9..c60acca 100644
--- a/include/eval.h
+++ b/include/eval.h
@@ -25,7 +25,7 @@ struct eval_s {
   /**
    * The input being evaluated.
    */
-  char* string;
+  const char* string;
   /**
    * The current index in the input.
    */
@@ -96,7 +96,7 @@ liblex_result eval_config_free(eval_config* config);
  * @param pattern_id the id to associate with the pattern
  * @return LIBLEX_SUCCESS if all goes well, or LIBLEX_MALLOC if there was an allocation failure.
  */
-liblex_result eval_config_add(eval_config* config, char* pattern, int pattern_id);
+liblex_result eval_config_add(eval_config* config, const char* pattern, int pattern_id);
 /**
  * Evaluates / finds a single word.
  * @param string the string to evaluate.
@@ -105,7 +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, size_t index, eval_config* config, match* match);
+liblex_result eval_word(const 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.
@@ -115,7 +115,7 @@ liblex_result eval_word(char* string, size_t index, eval_config* config, match*
  * @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, size_t index, eval_config* config, ll* matches);
+liblex_result eval_all(const 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,
diff --git a/src/eval.c b/src/eval.c
index abdebc0..ad6cc2c 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -14,7 +14,7 @@ static liblex_result foreach_errors[2] = {
 void eval_config_init(eval_config* config){
   ll_init(&config->states);
 }
-liblex_result eval_config_add(eval_config* config, char* ptrn, int pattern_id){
+liblex_result eval_config_add(eval_config* config, const char* ptrn, int pattern_id){
   liblex_result result;
   pattern* new_pattern = malloc(sizeof(*new_pattern));
   if(new_pattern){
@@ -154,7 +154,7 @@ int _eval_foreach_find_match(void *data, va_list args){
   return 0;
 }
 
-liblex_result eval_word(char* string, size_t index, eval_config* config, match* mtch){
+liblex_result eval_word(const char* string, size_t index, eval_config* config, match* mtch){
   liblex_result result = LIBLEX_SUCCESS;
   eval evl;
   evl.index = evl.begin = index;
@@ -177,8 +177,8 @@ liblex_result eval_word(char* string, size_t index, eval_config* config, match*
     int largest_id = -1;
     ll_foreach(&evl.matches, NULL, compare_always, _eval_foreach_find_match, &largest_id, mtch);
   } else {
-    mtch->from = -1;
-    mtch->to = -1;
+    mtch->from = 0;
+    mtch->to = 0;
     mtch->pattern = -1;
   }
 
@@ -189,7 +189,7 @@ liblex_result eval_word(char* string, size_t index, eval_config* config, match*
 
   return result;
 }
-liblex_result eval_all(char* string, size_t index, eval_config* config, ll* matches){
+liblex_result eval_all(const char* string, size_t index, eval_config* config, ll* matches){
   liblex_result result = LIBLEX_SUCCESS;
   match* new_match = NULL;
   int done = 0;