[vlc-devel] [PATCH 1/9] vlc_list: add a typedef vlc_list_node to clarify which is the list and which is the node
Steve Lhomme
robux4 at ycbcr.xyz
Mon Aug 20 12:57:10 CEST 2018
On 20/08/2018 12:05, Rémi Denis-Courmont wrote:
> This is standard terminology for a tree structure. Siblings are on
> same level. Children are below and parent is above.
For me a list is flat, not a tree. You can always transverse them back
and forth, but not up and down. The implementation doesn't do that either.
The main storage (head) is in one place and the nodes are in another one
and they are not equivalent.
>
> Le 20 août 2018 10:24:51 GMT+03:00, Steve Lhomme <robux4 at ycbcr.xyz> a
> écrit :
>
> An example of the confusion we want to avoid and what led me to dig into
> this code:
>
> vlc_list siblings
>
> Is is a list or a list item/node ? The plural led me to think it it's a
> list of siblings but I was wrong. Having "vlc_list_node siblings" would
> clear that confusion.
>
>
> On 20/08/2018 09:21, Steve Lhomme wrote:
>
> On 17/08/2018 19:06, Rémi Denis-Courmont wrote:
>
> You cannot have a different typedef here. This is by
> design. And we already use different member names for
> heads and nodes.
>
> It's possible, it's even desirable. "vlc_list node" is the
> part that doesn't make sense here. A node is not a list, the
> fact it shares the same internals is because of the current
> design. It may change in the future, but what is 100% is that
> a node must not be used as a vlc_list despite its type. And so
> it should not imply it can be from its type (maybe the
> mnemonic is wrong, who knows).
>
> Le 17 août 2018 16:04:33 GMT+03:00, Steve Lhomme
> <robux4 at ycbcr.xyz> a écrit : ---
> include/vlc_list.h | 23 +++++++++++++---------- 1
> file changed, 13 insertions(+), 10 deletions(-) diff
> --git a/include/vlc_list.h b/include/vlc_list.h index
> 45263cc789..002119db6b 100644 --- a/include/vlc_list.h
> +++ b/include/vlc_list.h @@ -45,6 +45,9 @@ struct
> vlc_list struct vlc_list *next; };
> +/* type to use in list items to differentiate with
> the list itself */ +typedef struct vlc_list
> vlc_list_node; + /** * Static initializer
> for a list head. */ @@ -66,7 +69,7 @@ static
> inline void vlc_list_init(struct vlc_list *restrict head)
> * \param prev Node pointer of the previous element.
> * \param next Node pointer of the next element.
> */ -static inline void
> vlc_list_add_between(struct vlc_list *restrict node,
> +static inline void vlc_list_add_between(vlc_list_node
> *restrict node,
> struct
> vlc_list *prev,
> struct
> vlc_list *next) { @@ -82,7 +85,7 @@ static
> inline void vlc_list_add_between(struct vlc_list *restrict
> node, * \param node Node pointer of the element to
> insert [OUT]. * \param prev Node pointer of the
> previous element. */ -static inline void
> vlc_list_add_after(struct vlc_list *restrict node,
> +static inline void vlc_list_add_after(vlc_list_node
> *restrict node,
> struct
> vlc_list *prev) {
> vlc_list_add_between(node, prev, prev->next); @@ -94,7
> +97,7 @@ static inline void vlc_list_add_after(struct
> vlc_list *restrict node, * \param node Node pointer
> of the element to insert [OUT]. * \param prev Node
> pointer of the next element. */ -static inline
> void vlc_list_add_before(struct vlc_list *restrict node,
> +static inline void vlc_list_add_before(vlc_list_node
> *restrict node,
> struct
> vlc_list *next) {
> vlc_list_add_between(node, next->prev, next); @@
> -106,7 +109,7 @@ static inline void
> vlc_list_add_before(struct vlc_list *restrict node,
> * \param node Node pointer of the element to append to the
> list [OUT]. * \param head Head pointer of the list
> to append the element to. */ -static inline
> void vlc_list_append(struct vlc_list *restrict node,
> +static inline void vlc_list_append(vlc_list_node
> *restrict node,
> struct vlc_list *head) {
> vlc_list_add_before(node, head); @@ -118,7 +121,7 @@
> static inline void vlc_list_append(struct vlc_list
> *restrict node, * \param node Node pointer of the
> element to prepend to the list [OUT]. * \param head
> Head pointer of the list to prepend the element to.
> */ -static inline void vlc_list_prepend(struct
> vlc_list *restrict node, +static inline void
> vlc_list_prepend(vlc_list_node *restrict node,
> struct vlc_list
> *head) { vlc_list_add_after(node, head);
> @@ -131,7 +134,7 @@ static inline void
> vlc_list_prepend(struct vlc_list *restrict node, *
> \warning The element must be inside a list. *
> Otherwise the behaviour is undefined. */
> -static inline void vlc_list_remove(struct vlc_list
> *restrict node) +static inline void
> vlc_list_remove(vlc_list_node *restrict node) {
> struct vlc_list *prev = node->prev;
> struct vlc_list *next = node->next; @@ -177,7 +180,7
> @@ static inline bool vlc_list_is_empty(const struct
> vlc_list *head) * \retval false The element is not
> first (or is in another list). * \retval true The
> element is first. */ -static inline bool
> vlc_list_is_first(const struct vlc_list *node, +static
> inline bool vlc_list_is_first(const vlc_list_node *node,
> const struct
> vlc_list *head) { return node->prev ==
> head; @@ -192,7 +195,7 @@ static inline bool
> vlc_list_is_first(const struct vlc_list *node, *
> \retval false The element is not last (or is in another
> list). * \retval true The element is last.
> */ -static inline bool vlc_list_is_last(const struct
> vlc_list *node, +static inline bool
> vlc_list_is_last(const vlc_list_node *node,
> const struct
> vlc_list *head) { return node->next ==
> head; @@ -289,7 +292,7 @@ static inline void
> *vlc_list_last_or_null(const struct vlc_list *head,
> } static inline void
> *vlc_list_prev_or_null(const struct vlc_list *head,
> - struct vlc_list
> *node, +
> vlc_list_node *node,
> size_t
> offset) { if (vlc_list_is_first(node,
> head)) @@ -298,7 +301,7 @@ static inline void
> *vlc_list_prev_or_null(const struct vlc_list *head,
> } static inline void
> *vlc_list_next_or_null(const struct vlc_list *head,
> - struct vlc_list
> *node, +
> vlc_list_node *node,
> size_t
> offset) { if (vlc_list_is_last(node,
> head)) -- Envoyé de mon appareil Android avec Courriel K-9
> Mail. Veuillez excuser ma brièveté.
> ------------------------------------------------------------------------
> vlc-devel mailing list To unsubscribe or modify your
> subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel
>
> ------------------------------------------------------------------------
> vlc-devel mailing list To unsubscribe or modify your
> subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel
>
>
> ------------------------------------------------------------------------
>
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel
>
>
> --
> Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez
> excuser ma brièveté.
>
>
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel
More information about the vlc-devel
mailing list