patch 9.1.1441: completion: code can be improved

Problem:  completion: code can be improved
Solution: remove reposition_match() and use mergesort_list(),
          for fuzzy completion, sort by fuzzy score immediately after
          setting a new leader (Girish Palya)

closes: #17460

Co-authored-by: glepnir <glephunter@gmail.com>
Signed-off-by: Girish Palya <girishji@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/insexpand.c

@@ -818,77 +818,6 @@ is_nearest_active(void)
     return (get_cot_flags() & (COT_NEAREST | COT_FUZZY)) == COT_NEAREST;
 }
 
-/*
- * Repositions a match in the completion list based on its proximity score.
- * If the match is at the head and has a higher score than the next node,
- * or if it's in the middle/tail and has a lower score than the previous node,
- * it is moved to the correct position while maintaining ascending order.
- */
-    static void
-reposition_match(compl_T *match)
-{
-    compl_T *insert_before = NULL;
-    compl_T *insert_after = NULL;
-
-    // Node is at head and score is too big
-    if (!match->cp_prev)
-    {
-	if (match->cp_next && match->cp_next->cp_score > 0 &&
-		match->cp_next->cp_score < match->cp_score)
-	{
-	    // <c-p>: compl_first_match is at head and newly inserted node
-	    compl_first_match = compl_curr_match = match->cp_next;
-	    // Find the correct position in ascending order
-	    insert_before = match->cp_next;
-	    do
-	    {
-		insert_after = insert_before;
-		insert_before = insert_before->cp_next;
-	    } while (insert_before && insert_before->cp_score > 0 &&
-		    insert_before->cp_score < match->cp_score);
-	}
-	else
-	    return;
-    }
-    // Node is at tail or in the middle but score is too small
-    else
-    {
-	if (match->cp_prev->cp_score > 0 && match->cp_prev->cp_score > match->cp_score)
-	{
-	    // <c-n>: compl_curr_match (and newly inserted match) is at tail
-	    if (!match->cp_next)
-		compl_curr_match = compl_curr_match->cp_prev;
-	    // Find the correct position in ascending order
-	    insert_after = match->cp_prev;
-	    do
-	    {
-		insert_before = insert_after;
-		insert_after = insert_after->cp_prev;
-	    } while (insert_after && insert_after->cp_score > 0 &&
-		    insert_after->cp_score > match->cp_score);
-	}
-	else
-	    return;
-    }
-
-    if (insert_after)
-    {
-	// Remove the match from its current position
-	if (match->cp_prev)
-	    match->cp_prev->cp_next = match->cp_next;
-	else
-	    compl_first_match = match->cp_next;
-	if (match->cp_next)
-	    match->cp_next->cp_prev = match->cp_prev;
-
-	// Insert the match at the correct position
-	match->cp_next = insert_before;
-	match->cp_prev = insert_after;
-	insert_after->cp_next = match;
-	insert_before->cp_prev = match;
-    }
-}
-
 /*
  * Add a match to the list of matches. The arguments are:
  *     str       - text of the match to add
@@ -948,10 +877,7 @@ ins_compl_add(
 						 || match->cp_str.string[len] == NUL))
 	    {
 		if (is_nearest_active() && score > 0 && score < match->cp_score)
-		{
 		    match->cp_score = score;
-		    reposition_match(match);
-		}
 		return NOTDONE;
 	    }
 	    match = match->cp_next;
@@ -1063,9 +989,6 @@ ins_compl_add(
 	compl_first_match = match;
     compl_curr_match = match;
 
-    if (is_nearest_active() && score > 0)
-	reposition_match(match);
-
     // Find the longest common string if still doing that.
     if (compl_get_longest && (flags & CP_ORIGINAL_TEXT) == 0 && !cfc_has_mode())
 	ins_compl_longest_match(match);
@@ -1476,6 +1399,69 @@ cp_compare_fuzzy(const void* a, const void* b)
     return (score_b > score_a) ? 1 : (score_b < score_a) ? -1 : 0;
 }
 
+    static int
+cp_compare_nearest(const void* a, const void* b)
+{
+    int score_a = ((compl_T*)a)->cp_score;
+    int score_b = ((compl_T*)b)->cp_score;
+    if (score_a < 0 || score_b < 0)
+	return 0;
+    return (score_a > score_b) ? 1 : (score_a < score_b) ? -1 : 0;
+}
+
+/*
+ * Set fuzzy score.
+ */
+    static void
+set_fuzzy_score(void)
+{
+    compl_T     *compl = compl_first_match->cp_prev;
+
+    if (compl_leader.string != NULL && compl_leader.length > 0)
+    {
+	compl = compl_first_match;
+	do
+	{
+	    compl->cp_score = fuzzy_match_str(compl->cp_str.string,
+		    compl_leader.string);
+	    compl = compl->cp_next;
+	} while (compl != NULL && !is_first_match(compl));
+    }
+}
+
+/*
+ * Sort completion matches, excluding the node that contains the leader.
+ */
+    static void
+sort_compl_match_list(int (*compare)(const void *, const void *))
+{
+    compl_T     *compl = compl_first_match->cp_prev;
+
+    if (!compl_first_match || is_first_match(compl_first_match->cp_next))
+	return;
+
+    ins_compl_make_linear();
+    if (compl_shows_dir_forward())
+    {
+	compl_first_match->cp_next->cp_prev = NULL;
+	compl_first_match->cp_next = mergesort_list(compl_first_match->cp_next,
+		cp_get_next, cp_set_next, cp_get_prev, cp_set_prev, compare);
+	compl_first_match->cp_next->cp_prev = compl_first_match;
+    }
+    else
+    {
+	compl->cp_prev->cp_next = NULL;
+	compl_first_match = mergesort_list(compl_first_match, cp_get_next,
+		cp_set_next, cp_get_prev, cp_set_prev, compare);
+	compl_T	*tail = compl_first_match;
+	while (tail->cp_next != NULL)
+	    tail = tail->cp_next;
+	tail->cp_next = compl;
+	compl->cp_prev = tail;
+    }
+    (void)ins_compl_make_cyclic();
+}
+
 /*
  * Build a popup menu to show the completion matches.
  * Returns the popup menu entry that should be selected. Returns -1 if nothing
@@ -1493,7 +1479,6 @@ ins_compl_build_pum(void)
     unsigned int cur_cot_flags = get_cot_flags();
     int		compl_no_select = (cur_cot_flags & COT_NOSELECT) != 0;
     int		fuzzy_filter = (cur_cot_flags & COT_FUZZY) != 0;
-    int		fuzzy_sort = fuzzy_filter && !(cur_cot_flags & COT_NOSORT);
     compl_T	*match_head = NULL;
     compl_T	*match_tail = NULL;
     compl_T	*match_next = NULL;
@@ -1515,45 +1500,6 @@ ins_compl_build_pum(void)
 	compl_shown_match = compl_no_select ? compl_first_match
 					    : compl_first_match->cp_next;
 
-    // When 'completeopt' contains "fuzzy" and leader is not NULL or empty,
-    // set the cp_score for later comparisons.
-    if (fuzzy_filter && compl_leader.string != NULL && compl_leader.length > 0)
-    {
-	compl = compl_first_match;
-	do
-	{
-	    compl->cp_score = fuzzy_match_str(compl->cp_str.string, compl_leader.string);
-	    compl = compl->cp_next;
-	} while (compl != NULL && !is_first_match(compl));
-    }
-
-    // Sort the linked list based on fuzzy score
-    if (fuzzy_sort && compl_leader.string != NULL && compl_leader.length > 0
-	    && !is_first_match(compl_first_match->cp_next))
-    {
-	compl = compl_first_match->cp_prev;
-	ins_compl_make_linear();
-	if (is_forward)
-	{
-	    compl_first_match->cp_next->cp_prev = NULL;
-	    compl_first_match->cp_next = mergesort_list(compl_first_match->cp_next, cp_get_next,
-		    cp_set_next, cp_get_prev, cp_set_prev, cp_compare_fuzzy);
-	    compl_first_match->cp_next->cp_prev = compl_first_match;
-	}
-	else
-	{
-	    compl->cp_prev->cp_next = NULL;
-	    compl_first_match = mergesort_list(compl_first_match, cp_get_next,
-		    cp_set_next, cp_get_prev, cp_set_prev, cp_compare_fuzzy);
-	    compl_T	*tail = compl_first_match;
-	    while (tail->cp_next != NULL)
-		tail = tail->cp_next;
-	    tail->cp_next = compl;
-	    compl->cp_prev = tail;
-	}
-	(void)ins_compl_make_cyclic();
-    }
-
     if (is_cpt_completion)
     {
 	match_count = ALLOC_CLEAR_MULT(int, cpt_sources_count);
@@ -2402,6 +2348,23 @@ ins_compl_new_leader(void)
 	compl_restarting = FALSE;
     }
 
+    // When 'cot' contains "fuzzy" set the cp_score
+    if (get_cot_flags() & COT_FUZZY)
+	set_fuzzy_score();
+    // Sort the matches linked list based on fuzzy score
+    int	cur_cot_flags = get_cot_flags();
+    if ((cur_cot_flags & COT_FUZZY) && !(cur_cot_flags & COT_NOSORT))
+    {
+	sort_compl_match_list(cp_compare_fuzzy);
+	if ((cur_cot_flags & COT_NOINSERT) && !(cur_cot_flags & COT_NOSELECT)
+		&& compl_first_match)
+	{
+	    compl_shown_match = compl_first_match;
+	    if (compl_shows_dir_forward())
+		compl_shown_match = compl_first_match->cp_next;
+	}
+    }
+
     compl_enter_selects = !compl_used_match && compl_selected_item != -1;
 
     // Show the popup menu with a different set of matches.
@@ -5296,6 +5259,9 @@ ins_compl_get_exp(pos_T *ini)
     }
     may_trigger_modechanged();
 
+    if (is_nearest_active())
+	sort_compl_match_list(cp_compare_nearest);
+
     return i;
 }
 
@@ -5518,7 +5484,7 @@ ins_compl_show_filename(void)
  * in 'compl_match_array'.
  */
     static compl_T *
-find_comp_when_cpt_sources(void)
+find_next_match_in_menu(void)
 {
     int	    is_forward = compl_shows_dir_forward();
     compl_T *match = compl_shown_match;
@@ -5555,14 +5521,13 @@ find_next_completion_match(
     unsigned int cur_cot_flags = get_cot_flags();
     int	    compl_no_select = (cur_cot_flags & COT_NOSELECT) != 0;
     int	    compl_fuzzy_match = (cur_cot_flags & COT_FUZZY) != 0;
-    int	    cpt_sources_active = compl_match_array && cpt_sources_array;
 
     while (--todo >= 0)
     {
 	if (compl_shows_dir_forward() && compl_shown_match->cp_next != NULL)
 	{
-	    if (cpt_sources_active)
+	    if (compl_match_array != NULL)
-		compl_shown_match = find_comp_when_cpt_sources();
+		compl_shown_match = find_next_match_in_menu();
 	    else
 		compl_shown_match = compl_shown_match->cp_next;
 	    found_end = (compl_first_match != NULL
@@ -5573,8 +5538,8 @@ find_next_completion_match(
 		&& compl_shown_match->cp_prev != NULL)
 	{
 	    found_end = is_first_match(compl_shown_match);
-	    if (cpt_sources_active)
+	    if (compl_match_array != NULL)
-		compl_shown_match = find_comp_when_cpt_sources();
+		compl_shown_match = find_next_match_in_menu();
 	    else
 		compl_shown_match = compl_shown_match->cp_prev;
 	    found_end |= is_first_match(compl_shown_match);

src/testdir/test_ins_complete.vim

@@ -3394,8 +3394,11 @@ func Test_complete_opt_fuzzy()
     endif
     if g:change == 0
       return [#{word: "foo"}, #{word: "foobar"}, #{word: "fooBaz"}, #{word: "foobala"}, #{word: "你好吗"}, #{word: "我好"}]
-    endif
+    elseif g:change == 1
+      return [#{word: "cp_match_array"}, #{word: "cp_str"}, #{word: "cp_score"}]
+    else
       return [#{word: "for i = .."}, #{word: "bar"}, #{word: "foo"}, #{word: "for .. ipairs"}, #{word: "for .. pairs"}]
+    endif
   endfunc
 
   new
@@ -3493,7 +3496,7 @@ func Test_complete_opt_fuzzy()
   call assert_equal('alpha bravio charlie', getline('.'))
 
   set cot=fuzzy,menu,noinsert
-  call feedkeys(":let g:change=1\<CR>")
+  call feedkeys(":let g:change=2\<CR>")
   call feedkeys("S\<C-X>\<C-O>for\<C-N>\<C-N>\<C-N>", 'tx')
   call assert_equal('for', getline('.'))
   call feedkeys("S\<C-X>\<C-O>for\<C-P>", 'tx')
@@ -3501,6 +3504,10 @@ func Test_complete_opt_fuzzy()
   call feedkeys("S\<C-X>\<C-O>for\<C-P>\<C-P>", 'tx')
   call assert_equal('for .. ipairs', getline('.'))
 
+  call feedkeys(":let g:change=1\<CR>")
+  call feedkeys("S\<C-X>\<C-O>c\<C-Y>", 'tx')
+  call assert_equal('cp_str', getline('.'))
+
   " clean up
   set omnifunc=
   bw!

src/version.c

@@ -709,6 +709,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1441,
 /**/
     1440,
 /**/