updated for version 7.4.218

Problem:    It's not easy to remove duplicates from a list.
Solution:   Add the uniq() function. (LCD)

runtime/doc/change.txt

@@ -1650,7 +1650,7 @@ And a few warnings:
 7. Sorting text						*sorting*
 
 Vim has a sorting function and a sorting command.  The sorting function can be
-found here: |sort()|.
+found here: |sort()|, |uniq()|.
 
 							*:sor* *:sort*
 :[range]sor[t][!] [i][u][r][n][x][o] [/{pattern}/]

runtime/doc/eval.txt

@@ -327,6 +327,7 @@ examples: >
 Changing the order of items in a list: >
 	:call sort(list)		" sort a list alphabetically
 	:call reverse(list)		" reverse the order of items
+	:call uniq(sort(list))		" sort and remove duplicates
 
 
 For loop ~
@@ -2005,6 +2006,8 @@ trunc( {expr})			Float	truncate Float {expr}
 type( {name})			Number	type of variable {name}
 undofile( {name})		String	undo file name for {name}
 undotree()			List	undo file tree
+uniq( {list} [, {func} [, {dict}]])
+				List	remove adjacent duplicates from a list
 values( {dict})			List	values in {dict}
 virtcol( {expr})		Number	screen column of cursor or mark
 visualmode( [expr])		String	last visual mode used
@@ -5488,20 +5491,26 @@ sinh({expr})						*sinh()*
 
 
 sort({list} [, {func} [, {dict}]])			*sort()* *E702*
-		Sort the items in {list} in-place.  Returns {list}.  If you
-		want a list to remain unmodified make a copy first: >
+		Sort the items in {list} in-place.  Returns {list}.
+		
+		If you want a list to remain unmodified make a copy first: >
 			:let sortedlist = sort(copy(mylist))
 <		Uses the string representation of each item to sort on.
 		Numbers sort after Strings, |Lists| after Numbers.
 		For sorting text in the current buffer use |:sort|.
+
 		When {func} is given and it is one then case is ignored.
-		{dict} is for functions with the "dict" attribute.  It will be
-		used to set the local variable "self". |Dictionary-function|
 		When {func} is a |Funcref| or a function name, this function
 		is called to compare items.  The function is invoked with two
 		items as argument and must return zero if they are equal, 1 or
 		bigger if the first one sorts after the second one, -1 or
 		smaller if the first one sorts before the second one.
+
+		{dict} is for functions with the "dict" attribute.  It will be
+		used to set the local variable "self". |Dictionary-function|
+
+		Also see |uniq()|.
+
 		Example: >
 			func MyCompare(i1, i2)
 			   return a:i1 == a:i2 ? 0 : a:i1 > a:i2 ? 1 : -1
@@ -6169,6 +6178,14 @@ undotree()						*undotree()*
 				blocks.  Each item may again have an "alt"
 				item.
 
+uniq({list} [, {func} [, {dict}]])			*uniq()* *E882*
+		Remove second and succeeding copies of repeated adjacent
+		{list} items in-place.  Returns {list}.  If you want a list
+		to remain unmodified make a copy first: >
+			:let newlist = uniq(copy(mylist))
+<		The default compare function uses the string representation of
+		each item.  For the use of {func} and {dict} see |sort()|.
+
 values({dict})						*values()*
 		Return a |List| with all the values of {dict}.	The |List| is
 		in arbitrary order.

runtime/doc/version7.txt

@@ -942,6 +942,7 @@ New and extended functions: ~
 |tagfiles()|		List with tags file names
 |taglist()|		get list of matching tags (Yegappan Lakshmanan)
 |tr()|			translate characters (Ron Aaron)
+|uniq()|		remove copies of repeated adjacent list items
 |values()|		get List of Dictionary values
 |winnr()|		takes an argument: what window to use
 |winrestview()|		restore the view of the current window