Re: Add gl_list_remove_last to list/xlist

[Bruno Haible]

> Done through the two attached patches.

And another patch, for the C++ interface.


2020-05-03  Bruno Haible  <address@hidden>

        list-c++: Add get_first, get_last, set_first, set_last operations.
        * lib/gl_list.hh (class gl_List): Add methods get_first, get_last,
        set_first, set_last.
        * lib/gl_list.h: Tweak comments.

diff --git a/lib/gl_list.h b/lib/gl_list.h
index 7786092..dfec6d0 100644
--- a/lib/gl_list.h
+++ b/lib/gl_list.h
@@ -215,11 +215,11 @@ extern gl_list_node_t gl_list_previous_node (gl_list_t 
list, gl_list_node_t node
 extern const void * gl_list_get_at (gl_list_t list, size_t position);
 
 /* Returns the element at the first position in the list.
-   LIST must be non-empty.  */
+   The list must be non-empty.  */
 extern const void * gl_list_get_first (gl_list_t list);
 
 /* Returns the element at the last position in the list.
-   LIST must be non-empty.  */
+   The list must be non-empty.  */
 extern const void * gl_list_get_last (gl_list_t list);
 
 /* Replaces the element at a given position in the list.
@@ -237,8 +237,8 @@ extern gl_list_node_t gl_list_nx_set_at (gl_list_t list, 
size_t position,
   ;
 
 /* Replaces the element at the first position in the list.
-   LIST must be non-empty.
-   Returns its node.  */
+   Returns its node.
+   The list must be non-empty.  */
 /* declared in gl_xlist.h */
 extern gl_list_node_t gl_list_set_first (gl_list_t list, const void *elt);
 /* Likewise.  Returns NULL upon out-of-memory.  */
@@ -249,8 +249,8 @@ extern gl_list_node_t gl_list_nx_set_first (gl_list_t list, 
const void *elt)
   ;
 
 /* Replaces the element at the last position in the list.
-   LIST must be non-empty.
-   Returns its node.  */
+   Returns its node.
+   The list must be non-empty.  */
 /* declared in gl_xlist.h */
 extern gl_list_node_t gl_list_set_last (gl_list_t list, const void *elt);
 /* Likewise.  Returns NULL upon out-of-memory.  */
diff --git a/lib/gl_list.hh b/lib/gl_list.hh
index 2cc83be..b19bda7 100644
--- a/lib/gl_list.hh
+++ b/lib/gl_list.hh
@@ -137,6 +137,16 @@ public:
   ELTYPE * get_at (size_t position) const
     { return static_cast<ELTYPE *>(gl_list_get_at (_ptr, position)); }
 
+  /* Returns the element at the first position in the list.
+     The list must be non-empty.  */
+  ELTYPE * get_first () const
+    { return static_cast<ELTYPE *>(gl_list_get_first (_ptr)); }
+
+  /* Returns the element at the last position in the list.
+     The list must be non-empty.  */
+  ELTYPE * get_last () const
+    { return static_cast<ELTYPE *>(gl_list_get_last (_ptr)); }
+
   /* Searches whether an element is already in the list.
      Returns its node if found, or NULL if not present in the list.  */
   gl_list_node_t search (ELTYPE * elt) const
@@ -183,6 +193,18 @@ public:
   gl_list_node_t set_at (size_t position, ELTYPE * elt)
     { return gl_list_set_at (_ptr, position, elt); }
 
+  /* Replaces the element at the first position in the list.
+     Returns its node.
+     The list must be non-empty.  */
+  gl_list_node_t set_first (ELTYPE * elt)
+    { return gl_list_set_first (_ptr, elt); }
+
+  /* Replaces the element at the last position in the list.
+     Returns its node.
+     The list must be non-empty.  */
+  gl_list_node_t set_last (ELTYPE * elt)
+    { return gl_list_set_last (_ptr, elt); }
+
   /* Adds an element as the first element of the list.
      Returns its node.  */
   gl_list_node_t add_first (ELTYPE * elt)