Re: [PATCH 2/4] Add a new function, filter_string_list()

> Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
> ---
>  Documentation/technical/api-string-list.txt |  8 ++++++++
>  string-list.c                               | 17 +++++++++++++++++
>  string-list.h                               |  9 +++++++++
>  3 files changed, 34 insertions(+)
>
> diff --git a/Documentation/technical/api-string-list.txt b/Documentation/technical/api-string-list.txt
> index 3b959a2..15b8072 100644
> --- a/Documentation/technical/api-string-list.txt
> +++ b/Documentation/technical/api-string-list.txt
> @@ -60,6 +60,14 @@ Functions
>  
>  * General ones (works with sorted and unsorted lists as well)
>  
> +`filter_string_list`::
> +
> +	Apply a function to each item in a list, retaining only the
> +	items for which the function returns true.  If free_util is
> +	true, call free() on the util members of any items that have
> +	to be deleted.  Preserve the order of the items that are
> +	retained.

>  `print_string_list`::
>  
>  	Dump a string_list to stdout, useful mainly for debugging purposes. It
> diff --git a/string-list.c b/string-list.c
> index 110449c..72610ce 100644
> --- a/string-list.c
> +++ b/string-list.c
> @@ -102,6 +102,23 @@ int for_each_string_list(struct string_list *list,
>  	return ret;
>  }
>  
> +void filter_string_list(struct string_list *list, int free_util,
> +			string_list_each_func_t fn, void *cb_data)
> +{
> +	int src, dst = 0;
> +	for (src = 0; src < list->nr; src++) {
> +		if (fn(&list->items[src], cb_data)) {
> +			list->items[dst++] = list->items[src];
> +		} else {
> +			if (list->strdup_strings)
> +				free(list->items[src].string);
> +			if (free_util)
> +				free(list->items[src].util);
> +		}
> +	}
> +	list->nr = dst;
> +}
> +
>  void string_list_clear(struct string_list *list, int free_util)
>  {
>  	if (list->items) {
> diff --git a/string-list.h b/string-list.h
> index 7e51d03..84996aa 100644
> --- a/string-list.h
> +++ b/string-list.h
> @@ -29,6 +29,15 @@ int for_each_string_list(struct string_list *list,
>  #define for_each_string_list_item(item,list) \
>  	for (item = (list)->items; item < (list)->items + (list)->nr; ++item)
>  
> +/*
> + * Apply fn to each item in list, retaining only the ones for which
> + * the function returns true.  If free_util is true, call free() on
> + * the util members of any items that have to be deleted.  Preserve
> + * the order of the items that are retained.
> + */
> +void filter_string_list(struct string_list *list, int free_util,
> +			string_list_each_func_t fn, void *cb_data);
> +
>  /* Use these functions only on sorted lists: */
>  int string_list_has_string(const struct string_list *list, const char *string);
>  int string_list_find_insert_index(const struct string_list *list, const char *string,