Minor refactor to parsing and testing cleanup

src/parse.c

@@ -57,7 +57,7 @@ struct ucl_object *ucl_token_next(const char **curr_src) {
                 str[0] = **curr_src;
                 str[1] = '\0';
                 (*curr_src)++;
-                return ucl_cell_create(ucl_symbol_create(str), NULL);
+                return ucl_symbol_create(str);
             case QUOTE_CHAR:
                 // skip beginning quote
                 (*curr_src)++;
@@ -69,20 +69,22 @@ struct ucl_object *ucl_token_next(const char **curr_src) {
                 (*curr_src)++;
                 // -2 for removing start/end quotes
                 str = strndup(start + 1, *curr_src - start - 2);
-                return ucl_cell_create(ucl_string_create(str), NULL);
+                // TODO: free
+                return ucl_string_create(str);
             case '0'...'9': {
                 // TODO: Add support for negative integers
                 char *end = NULL;
                 long value = strtol(*curr_src, &end, 0);
                 *curr_src = end;
-                return ucl_cell_create(ucl_int_create(value), NULL);
+                return ucl_int_create(value);
             }
             default:
                 while (!ucl_is_delimiter(**curr_src)) {
                     (*curr_src)++;
                 }
+                // TODO: Free
                 str = strndup(start, *curr_src - start);
-                return ucl_cell_create(ucl_symbol_create(str), NULL);
+                return ucl_symbol_create(str);
         }
     }
 
@@ -92,12 +94,12 @@ struct ucl_object *ucl_token_next(const char **curr_src) {
 }
 
 struct ucl_object *ucl_tokenize(const char *source) {
-    struct ucl_object *tokens = NULL, *curr_token = NULL, **next_token = &tokens;
+    struct ucl_object *tokens = ucl_nil_create();
+    struct ucl_object *curr_token = NULL;
     const char *curr_src = source;
 
     while ((curr_token = ucl_token_next(&curr_src)) != NULL) {
-        *next_token = curr_token;
-        next_token = &curr_token->cell.cdr;
+        ucl_list_append(tokens, curr_token);
     }
 
     return tokens;
@@ -197,9 +199,9 @@ static struct ucl_object *ucl_parse_tokens_recursive(struct ucl_object **token_i
 // parse_tokens_recursive -> error on EOF)
 
 struct ucl_object *ucl_parse_tokens(struct ucl_object *tokens) {
-    struct ucl_object* resultl = NULL;
+    struct ucl_object* result = ucl_nil_create();
+    struct ucl_object* result_tail = result;
     struct ucl_object** token_iter = &tokens;
-    struct ucl_object** next_cell = &resultl;
 
     while (*token_iter != NULL) {
         struct ucl_object *new_sexp = ucl_parse_tokens_recursive(token_iter);
@@ -207,25 +209,18 @@ struct ucl_object *ucl_parse_tokens(struct ucl_object *tokens) {
             return new_sexp;
         }
 
-        *next_cell = ucl_cell_create(new_sexp, NULL);
-        next_cell = &(*next_cell)->cell.cdr;
+        ucl_list_append(result_tail, new_sexp);
     }
 
-    if (resultl == NULL) {
-        return ucl_cell_create(NULL, NULL);
-    }
-
-    return resultl;
+    return result;
 }
 
 // TODO: Should the parse a single sexp (return the last-parsed position), or
 // all sexps in the source (return a list of sexps)?
 struct ucl_object *ucl_parse(const char *source) {
     struct ucl_object *tokens = ucl_tokenize(source);
-    if (tokens == NULL) {
-        tokens = ucl_nil_create();
-    }
     UCL_RET_IF_ERROR(tokens);
+
     struct ucl_object *sexp  = ucl_parse_tokens(tokens);
     if (sexp == NULL) {
         return ucl_nil_create();

src/utility.c

@@ -116,7 +116,7 @@ struct ucl_object *ucl_list_append(struct ucl_object *list, struct ucl_object *o
 
     if (list->cell.car == NULL) {
         list->cell.car = obj;
-        return list;
+        return NULL;
     }
 
     while (iter->cell.cdr != NULL) {
@@ -124,7 +124,7 @@ struct ucl_object *ucl_list_append(struct ucl_object *list, struct ucl_object *o
     }
     iter->cell.cdr = ucl_cell_create(obj, NULL);
 
-    return list;
+    return iter->cell.cdr;
 }
 
 void ucl_print_obj(struct ucl_object *obj) {