Merge #15293 Vimscript "method" syntax

Port VimL's method call syntax - vim-patch:8.1.{1638,1800,1803,1807,1809,1816,1820,1821,1828,1834,1835,1861,1863,1878,1879,1888,1909,1911,1912}

runtime/doc/eval.txt

@@ -669,12 +669,14 @@ Expression syntax summary, from least to most significant:
 	expr8[expr1 : expr1]	substring of a String or sublist of a |List|
 	expr8.name		entry in a |Dictionary|
 	expr8(expr1, ...)	function call with |Funcref| variable
+	expr8->name(expr1, ...)	|method| call
 
 |expr9|	number			number constant
 	"string"		string constant, backslash is special
 	'string'		string constant, ' is doubled
 	[expr1, ...]		|List|
 	{expr1: expr1, ...}	|Dictionary|
+	#{key: expr1, ...}	|Dictionary|
 	&option			option value
 	(expr1)			nested expression
 	variable		internal variable
@@ -939,9 +941,11 @@ expr8							*expr8*
 -----
 This expression is either |expr9| or a sequence of the alternatives below,
 in any order.  E.g., these are all possible:
-	expr9[expr1].name
+	expr8[expr1].name
-	expr9.name[expr1]
+	expr8.name[expr1]
-	expr9(expr1, ...)[expr1].name
+	expr8(expr1, ...)[expr1].name
+	expr8->(expr1, ...)[expr1]
+Evaluation is always from left to right.
 
 
 expr8[expr1]		item of String or |List|	*expr-[]* *E111*
@@ -1043,6 +1047,36 @@ expr8(expr1, ...)	|Funcref| function call
 When expr8 is a |Funcref| type variable, invoke the function it refers to.
 
 
+expr8->name([args])	method call			*method* *->*
+expr8->{lambda}([args])
+
+For methods that are also available as global functions this is the same as: >
+	name(expr8 [, args])
+There can also be methods specifically for the type of "expr8".
+
+This allows for chaining, passing the value that one method returns to the
+next method: >
+	mylist->filter(filterexpr)->map(mapexpr)->sort()->join()
+<
+Example of using a lambda: >
+	GetPercentage->{x -> x * 100}()->printf('%d%%')
+<
+When using -> the |expr7| operators will be applied first, thus: >
+	-1.234->string()
+Is equivalent to: >
+	(-1.234)->string()
+And NOT: >
+	-(1.234->string())
+<
+							*E274*
+"->name(" must not contain white space.  There can be white space before the
+"->" and after the "(", thus you can split the lines like this: >
+	mylist
+	\ ->filter(filterexpr)
+	\ ->map(mapexpr)
+	\ ->sort()
+	\ ->join()
+<
 
 							*expr9*
 number
@@ -2583,6 +2617,8 @@ abs({expr})							*abs()*
 			echo abs(-4)
 <			4
 
+		Can also be used as a |method|: >
+			Compute()->abs()
 
 acos({expr})							*acos()*
 		Return the arc cosine of {expr} measured in radians, as a
@@ -2595,6 +2631,8 @@ acos({expr})							*acos()*
 			:echo acos(-0.5)
 <			2.094395
 
+		Can also be used as a |method|: >
+			Compute()->acos()
 
 add({list}, {expr})					*add()*
 		Append the item {expr} to |List| {list}.  Returns the
@@ -2605,12 +2643,16 @@ add({list}, {expr})					*add()*
 		item.  Use |extend()| to concatenate |Lists|.
 		Use |insert()| to add an item at another position.
 
+		Can also be used as a |method|: >
+			mylist->add(val1)->add(val2)
 
 and({expr}, {expr})					*and()*
 		Bitwise AND on the two arguments.  The arguments are converted
 		to a number.  A List, Dict or Float argument causes an error.
 		Example: >
 			:let flag = and(bits, 0x80)
+<		Can also be used as a |method|: >
+			:let flag = bits->and(0x80)
 
 api_info()						*api_info()*
 		Returns Dictionary of |api-metadata|.
@@ -2629,6 +2671,9 @@ append({lnum}, {text})					*append()*
 			:let failed = append(line('$'), "# THE END")
 			:let failed = append(0, ["Chapter 1", "the beginning"])
 
+<		Can also be used as a |method| after a List: >
+			mylist->append(lnum)
+
 appendbufline({expr}, {lnum}, {text})			*appendbufline()*
 		Like |append()| but append the text in buffer {expr}.
 
@@ -2647,8 +2692,10 @@ appendbufline({expr}, {lnum}, {text})			*appendbufline()*
 		error message is given. Example: >
 			:let failed = appendbufline(13, 0, "# THE START")
 <
-							*argc()*
+		Can also be used as a |method| after a List: >
-argc([{winid}])
+			mylist->appendbufline(buf, lnum)
+
+argc([{winid}])					*argc()*
 		The result is the number of files in the argument list.  See
 		|arglist|.
 		If {winid} is not supplied, the argument list of the current
@@ -2702,6 +2749,9 @@ asin({expr})						*asin()*
 			:echo asin(-0.5)
 <			-0.523599
 
+		Can also be used as a |method|: >
+			Compute()->asin()
+
 
 assert_ functions are documented here: |assert-functions-details|
 
@@ -2716,6 +2766,8 @@ atan({expr})						*atan()*
 			:echo atan(-4.01)
 <			-1.326405
 
+		Can also be used as a |method|: >
+			Compute()->atan()
 
 atan2({expr1}, {expr2})					*atan2()*
 		Return the arc tangent of {expr1} / {expr2}, measured in
@@ -2727,6 +2779,8 @@ atan2({expr1}, {expr2})					*atan2()*
 			:echo atan2(1, -1)
 <			2.356194
 
+		Can also be used as a |method|: >
+			Compute()->atan2(1)
 
 							*browse()*
 browse({save}, {title}, {initdir}, {default})
@@ -2737,8 +2791,8 @@ browse({save}, {title}, {initdir}, {default})
 		    {title}	title for the requester
 		    {initdir}	directory to start browsing in
 		    {default}	default file name
-		When the "Cancel" button is hit, something went wrong, or
+		An empty string is returned when the "Cancel" button is hit,
-		browsing is not possible, an empty string is returned.
+		something went wrong, or browsing is not possible.
 
 							*browsedir()*
 browsedir({title}, {initdir})
@@ -2760,6 +2814,8 @@ bufadd({name})						*bufadd()*
 		created buffer.  When {name} is an empty string then a new
 		buffer is always created.
 		The buffer will not have' 'buflisted' set.
+<		Can also be used as a |method|: >
+			let bufnr = 'somename'->bufadd()
 
 bufexists({expr})					*bufexists()*
 		The result is a Number, which is |TRUE| if a buffer called
@@ -2783,11 +2839,17 @@ bufexists({expr})					*bufexists()*
 		Use "bufexists(0)" to test for the existence of an alternate
 		file name.
 
+		Can also be used as a |method|: >
+			let exists = 'somename'->bufexists()
+
 buflisted({expr})					*buflisted()*
 		The result is a Number, which is |TRUE| if a buffer called
 		{expr} exists and is listed (has the 'buflisted' option set).
 		The {expr} argument is used like with |bufexists()|.
 
+		Can also be used as a |method|: >
+			let listed = 'somename'->buflisted()
+
 bufload({expr})						*bufload()*
 		Ensure the buffer {expr} is loaded.  When the buffer name
 		refers to an existing file then the file is read.  Otherwise
@@ -2797,15 +2859,21 @@ bufload({expr})						*bufload()*
 		there will be no dialog, the buffer will be loaded anyway.
 		The {expr} argument is used like with |bufexists()|.
 
+		Can also be used as a |method|: >
+			eval 'somename'->bufload()
+
 bufloaded({expr})					*bufloaded()*
 		The result is a Number, which is |TRUE| if a buffer called
 		{expr} exists and is loaded (shown in a window or hidden).
 		The {expr} argument is used like with |bufexists()|.
 
+		Can also be used as a |method|: >
+			let loaded = 'somename'->bufloaded()
+
 bufname([{expr}])						*bufname()*
 		The result is the name of a buffer, as it is displayed by the
 		":ls" command.
-+		If {expr} is omitted the current buffer is used.
+		If {expr} is omitted the current buffer is used.
 		If {expr} is a Number, that buffer number's name is given.
 		Number zero is the alternate buffer for the current window.
 		If {expr} is a String, it is used as a |file-pattern| to match
@@ -2824,6 +2892,9 @@ bufname([{expr}])						*bufname()*
 		If the {expr} is a String, but you want to use it as a buffer
 		number, force it to be a Number by adding zero to it: >
 			:echo bufname("3" + 0)
+<		Can also be used as a |method|: >
+			echo bufnr->bufname()
+
 <		If the buffer doesn't exist, or doesn't have a name, an empty
 		string is returned. >
 	bufname("#")		alternate buffer name
@@ -2846,6 +2917,9 @@ bufnr([{expr} [, {create}]])
 		number necessarily exist, because ":bwipeout" may have removed
 		them.  Use bufexists() to test for the existence of a buffer.
 
+		Can also be used as a |method|: >
+			echo bufref->bufnr()
+
 bufwinid({expr})					*bufwinid()*
 		The result is a Number, which is the |window-ID| of the first
 		window associated with buffer {expr}.  For the use of {expr},
@@ -2856,18 +2930,22 @@ bufwinid({expr})					*bufwinid()*
 <
 		Only deals with the current tab page.
 
+		Can also be used as a |method|: >
+			FindBuffer()->bufwinid()
+
 bufwinnr({expr})					*bufwinnr()*
-		The result is a Number, which is the number of the first
+		Like |bufwinid()| but return the window number instead of the
-		window associated with buffer {expr}.  For the use of {expr},
+		|window-ID|.
-		see |bufname()| above.  If buffer {expr} doesn't exist or
+		If buffer {expr} doesn't exist or there is no such window, -1
-		there is no such window, -1 is returned.  Example: >
+		is returned.  Example: >
 
 	echo "A window containing buffer 1 is " . (bufwinnr(1))
 
 <		The number can be used with |CTRL-W_w| and ":wincmd w"
 		|:wincmd|.
-		Only deals with the current tab page.
 
+		Can also be used as a |method|: >
+			FindBuffer()->bufwinnr()
 
 byte2line({byte})					*byte2line()*
 		Return the line number that contains the character at byte
@@ -2877,6 +2955,9 @@ byte2line({byte})					*byte2line()*
 		one.
 		Also see |line2byte()|, |go| and |:goto|.
 
+		Can also be used as a |method|: >
+			GetOffset()->byte2line()
+
 byteidx({expr}, {nr})					*byteidx()*
 		Return byte index of the {nr}'th character in the string
 		{expr}.  Use zero for the first character, it then returns
@@ -2899,6 +2980,9 @@ byteidx({expr}, {nr})					*byteidx()*
 		If there are exactly {nr} characters the length of the string
 		in bytes is returned.
 
+		Can also be used as a |method|: >
+			GetName()->byteidx(idx)
+
 byteidxcomp({expr}, {nr})					*byteidxcomp()*
 		Like byteidx(), except that a composing character is counted
 		as a separate character.  Example: >
@@ -2912,6 +2996,9 @@ byteidxcomp({expr}, {nr})					*byteidxcomp()*
 		Only works differently from byteidx() when 'encoding' is set to
 		a Unicode encoding.
 
+		Can also be used as a |method|: >
+			GetName()->byteidxcomp(idx)
+
 call({func}, {arglist} [, {dict}])			*call()* *E699*
 		Call function {func} with the items in |List| {arglist} as
 		arguments.
@@ -2921,6 +3008,9 @@ call({func}, {arglist} [, {dict}])			*call()* *E699*
 		{dict} is for functions with the "dict" attribute.  It will be
 		used to set the local variable "self". |Dictionary-function|
 
+		Can also be used as a |method|: >
+			GetFunc()->call([arg, arg], dict)
+
 ceil({expr})							*ceil()*
 		Return the smallest integral value greater than or equal to
 		{expr} as a |Float| (round up).
@@ -2933,6 +3023,9 @@ ceil({expr})							*ceil()*
 			echo ceil(4.0)
 <			4.0
 
+		Can also be used as a |method|: >
+			Compute()->ceil()
+
 changenr()						*changenr()*
 		Return the number of the most recent change.  This is the same
 		number as what is displayed with |:undolist| and can be used
@@ -2982,6 +3075,9 @@ char2nr({expr} [, {utf8}])					*char2nr()*
 		A combining character is a separate character.
 		|nr2char()| does the opposite.
 
+		Can also be used as a |method|: >
+			GetChar()->char2nr()
+
 							*charidx()*
 charidx({string}, {idx} [, {countcc}])
 		Return the character index of the byte at {idx} in {string}.
@@ -3013,12 +3109,18 @@ cindent({lnum})						*cindent()*
 		When {lnum} is invalid -1 is returned.
 		See |C-indenting|.
 
+		Can also be used as a |method|: >
+			GetLnum()->cindent()
+
 clearmatches([{win}])					*clearmatches()*
  		Clears all matches previously defined for the current window
  		by |matchadd()| and the |:match| commands.
 		If {win} is specified, use the window with this number or
 		window ID instead of the current window.
 
+		Can also be used as a |method|: >
+			GetWin()->clearmatches()
+<
 							*col()*
 col({expr})	The result is a Number, which is the byte index of the column
 		position given with {expr}.  The accepted positions are:
@@ -3054,6 +3156,9 @@ col({expr})	The result is a Number, which is the byte index of the column
 				\<C-O>:set ve=all<CR>
 				\<C-O>:echo col(".") . "\n" <Bar>
 				\let &ve = save_ve<CR>
+
+<		Can also be used as a |method|: >
+			GetPos()->col()
 <
 
 complete({startcol}, {matches})			*complete()* *E785*
@@ -3085,6 +3190,10 @@ complete({startcol}, {matches})			*complete()* *E785*
 <		This isn't very useful, but it shows how it works.  Note that
 		an empty string is returned to avoid a zero being inserted.
 
+		Can also be used as a |method|, the second argument is passed
+		in: >
+			GetMatches()->complete(col('.'))
+
 complete_add({expr})				*complete_add()*
 		Add {expr} to the list of matches.  Only to be used by the
 		function specified with the 'completefunc' option.
@@ -3094,6 +3203,9 @@ complete_add({expr})				*complete_add()*
 		See |complete-functions| for an explanation of {expr}.  It is
 		the same as one item in the list that 'omnifunc' would return.
 
+		Can also be used as a |method|: >
+			GetMoreMatches()->complete_add()
+
 complete_check()				*complete_check()*
 		Check for a key typed while looking for completion matches.
 		This is to be used when looking for matches takes some time.
@@ -3154,6 +3266,9 @@ complete_info([{what}])
 			call complete_info(['mode'])
 			" Get only 'mode' and 'pum_visible'
 			call complete_info(['mode', 'pum_visible'])
+
+<		Can also be used as a |method|: >
+			GetItems()->complete_info()
 <
 						*confirm()*
 confirm({msg} [, {choices} [, {default} [, {type}]]])
@@ -3207,6 +3322,9 @@ confirm({msg} [, {choices} [, {default} [, {type}]]])
 		don't fit, a vertical layout is used anyway.  For some systems
 		the horizontal layout is always used.
 
+		Can also be used as a |method|in: >
+			BuildMessage()->confirm("&Yes\n&No")
+
 							*copy()*
 copy({expr})	Make a copy of {expr}.  For Numbers and Strings this isn't
 		different from using {expr} directly.
@@ -3216,6 +3334,8 @@ copy({expr})	Make a copy of {expr}.  For Numbers and Strings this isn't
 		changing an item changes the contents of both |Lists|.
 		A |Dictionary| is copied in a similar way as a |List|.
 		Also see |deepcopy()|.
+		Can also be used as a |method|: >
+			mylist->copy()
 
 cos({expr})						*cos()*
 		Return the cosine of {expr}, measured in radians, as a |Float|.
@@ -3226,6 +3346,8 @@ cos({expr})						*cos()*
 			:echo cos(-4.01)
 <			-0.646043
 
+		Can also be used as a |method|: >
+			Compute()->cos()
 
 cosh({expr})						*cosh()*
 		Return the hyperbolic cosine of {expr} as a |Float| in the range
@@ -3237,6 +3359,8 @@ cosh({expr})						*cosh()*
 			:echo cosh(-0.5)
 <			-1.127626
 
+		Can also be used as a |method|: >
+			Compute()->cosh()
 
 count({comp}, {expr} [, {ic} [, {start}]])			*count()*
 		Return the number of times an item with value {expr} appears
@@ -3251,6 +3375,9 @@ count({comp}, {expr} [, {ic} [, {start}]])			*count()*
 		occurrences of {expr} is returned. Zero is returned when
 		{expr} is an empty string.
 
+		Can also be used as a |method|: >
+			mylist->count(val)
+
 							*cscope_connection()*
 cscope_connection([{num} , {dbpath} [, {prepend}]])
 		Checks for the existence of a |cscope| connection.  If no
@@ -3346,6 +3473,8 @@ cursor({list})
 		position within a <Tab> or after the last character.
 		Returns 0 when the position could be set, -1 otherwise.
 
+		Can also be used as a |method|: >
+			GetCursorPos()->cursor()
 
 deepcopy({expr}[, {noref}])				*deepcopy()* *E698*
 		Make a copy of {expr}.  For Numbers and Strings this isn't
@@ -3367,6 +3496,9 @@ deepcopy({expr}[, {noref}])				*deepcopy()* *E698*
 		{noref} set to 1 will fail.
 		Also see |copy()|.
 
+		Can also be used as a |method|: >
+			GetObject()->deepcopy()
+
 delete({fname} [, {flags}])					*delete()*
 		Without {flags} or with {flags} empty: Deletes the file by the
 		name {fname}.  This also works when {fname} is a symbolic link.
@@ -3384,6 +3516,9 @@ delete({fname} [, {flags}])					*delete()*
 		operation was successful and -1/true when the deletion failed
 		or partly failed.
 
+		Can also be used as a |method|: >
+			GetName()->delete()
+
 deletebufline({expr}, {first}[, {last}])		*deletebufline()*
 		Delete lines {first} to {last} (inclusive) from buffer {expr}.
 		If {last} is omitted then delete line {first} only.
@@ -3398,6 +3533,9 @@ deletebufline({expr}, {first}[, {last}])		*deletebufline()*
 		when using |line()| this refers to the current buffer. Use "$"
 		to refer to the last line in buffer {expr}.
 
+		Can also be used as a |method|: >
+			GetBuffer()->deletebufline(1)
+
 dictwatcheradd({dict}, {pattern}, {callback})		      *dictwatcheradd()*
 		Adds a watcher to a dictionary. A dictionary watcher is
 		identified by three components:
@@ -3464,6 +3602,9 @@ diff_filler({lnum})					*diff_filler()*
 		line, "'m" mark m, etc.
 		Returns 0 if the current window is not in diff mode.
 
+		Can also be used as a |method|: >
+			GetLnum()->diff_filler()
+
 diff_hlID({lnum}, {col})				*diff_hlID()*
 		Returns the highlight ID for diff mode at line {lnum} column
 		{col} (byte index).  When the current line does not have a
@@ -3475,11 +3616,16 @@ diff_hlID({lnum}, {col})				*diff_hlID()*
 		The highlight ID can be used with |synIDattr()| to obtain
 		syntax information about the highlighting.
 
+		Can also be used as a |method|: >
+			GetLnum()->diff_hlID(col)
+
 empty({expr})						*empty()*
 		Return the Number 1 if {expr} is empty, zero otherwise.
 		A |List| or |Dictionary| is empty when it does not have any
 		items.  A Number is empty when its value is zero.  Special
 		variable is empty when it is |v:false| or |v:null|.
+		Can also be used as a |method|: >
+			mylist->empty()
 
 environ()						*environ()*
 		Return all of environment variables as dictionary. You can
@@ -3504,6 +3650,9 @@ eval({string})	Evaluate {string} and return the result.  Especially useful to
 		them.  Also works for |Funcref|s that refer to existing
 		functions.
 
+		Can also be used as a |method|: >
+			argv->join()->eval()
+
 eventhandler()						*eventhandler()*
 		Returns 1 when inside an event handler.  That is that Vim got
 		interrupted while waiting for the user to type a character,
@@ -3661,12 +3810,18 @@ exp({expr})						*exp()*
 			:echo exp(-1)
 <			0.367879
 
+		Can also be used as a |method|: >
+			Compute()->exp()
+
 debugbreak({pid})					*debugbreak()*
 		Specifically used to interrupt a program being debugged.  It
 		will cause process {pid} to get a SIGTRAP.  Behavior for other
 		processes is undefined. See |terminal-debugger|.
 		{Sends a SIGINT to a process {pid} other than MS-Windows}
 
+		Can also be used as a |method|: >
+			GetPid()->debugbreak()
+
 expand({expr} [, {nosuf} [, {list}]])				*expand()*
 		Expand wildcards and the following special keywords in {expr}.
 		'wildignorecase' applies.
@@ -3795,6 +3950,8 @@ extend({expr1}, {expr2} [, {expr3}])			*extend()*
 		fails.
 		Returns {expr1}.
 
+		Can also be used as a |method|: >
+			mylist->extend(otherlist)
 
 feedkeys({string} [, {mode}])				*feedkeys()*
 		Characters in {string} are queued for processing as if they
@@ -3848,7 +4005,11 @@ filereadable({file})					*filereadable()*
 		expression, which is used as a String.
 		If you don't care about the file being readable you can use
 		|glob()|.
-
+		{file} is used as-is, you may want to expand wildcards first: >
+			echo filereadable('~/.vimrc')
+			0
+			echo filereadable(expand('~/.vimrc'))
+			1
 
 filewritable({file})					*filewritable()*
 		The result is a Number, which is 1 when a file with the
@@ -3904,6 +4065,8 @@ filter({expr1}, {expr2})					*filter()*
 		Funcref errors inside a function are ignored, unless it was
 		defined with the "abort" flag.
 
+		Can also be used as a |method|: >
+			mylist->filter(expr2)
 
 finddir({name} [, {path} [, {count}]])				*finddir()*
 		Find directory {name} in {path}.  Supports both downwards and
@@ -3966,6 +4129,8 @@ float2nr({expr})					*float2nr()*
 			echo float2nr(1.0e-100)
 <			0
 
+		Can also be used as a |method|: >
+			Compute()->float2nr()
 
 floor({expr})							*floor()*
 		Return the largest integral value less than or equal to
@@ -3979,6 +4144,8 @@ floor({expr})							*floor()*
 			echo floor(4.0)
 <			4.0
 
+		Can also be used as a |method|: >
+			Compute()->floor()
 
 fmod({expr1}, {expr2})					*fmod()*
 		Return the remainder of {expr1} / {expr2}, even if the
@@ -3994,6 +4161,8 @@ fmod({expr1}, {expr2})					*fmod()*
 			:echo fmod(-12.33, 1.22)
 <			-0.13
 
+		Can also be used as a |method|: >
+			Compute()->fmod(1.22)
 
 fnameescape({string})					*fnameescape()*
 		Escape {string} for use as file name command argument.  All
@@ -4160,6 +4329,8 @@ get({list}, {idx} [, {default}])			*get()*
 		Get item {idx} from |List| {list}.  When this item is not
 		available return {default}.  Return zero when {default} is
 		omitted.
+		Can also be used as a |method|: >
+			mylist->get(idx)
 get({dict}, {key} [, {default}])
 		Get item with key {key} from |Dictionary| {dict}.  When this
 		item is not available return {default}.  Return zero when
@@ -5171,6 +5342,9 @@ has_key({dict}, {key})					*has_key()*
 		The result is a Number, which is TRUE if |Dictionary| {dict}
 		has an entry with key {key}.  FALSE otherwise.
 
+		Can also be used as a |method|: >
+			mydict->has_key(key)
+
 haslocaldir([{winnr}[, {tabnr}]])			*haslocaldir()*
 		The result is a Number, which is 1 when the tabpage or window
 		has set a local path via |:tcd| or |:lcd|, otherwise 0.
@@ -5514,6 +5688,9 @@ insert({list}, {item} [, {idx}])			*insert()*
 		Note that when {item} is a |List| it is inserted as a single
 		item.  Use |extend()| to concatenate |Lists|.
 
+		Can also be used as a |method|: >
+			mylist->insert(item)
+
 interrupt()						*interrupt()*
 		Interrupt script execution.  It works more or less like the
 		user typing CTRL-C, most commands won't execute and control
@@ -5531,6 +5708,8 @@ invert({expr})						*invert()*
 		Bitwise invert.  The argument is converted to a number.  A
 		List, Dict or Float argument causes an error.  Example: >
 			:let bits = invert(bits)
+<		Can also be used as a |method|: >
+			:let bits = bits->invert()
 
 isdirectory({directory})				*isdirectory()*
 		The result is a Number, which is |TRUE| when a directory
@@ -5546,6 +5725,9 @@ isinf({expr})						*isinf()*
 			:echo isinf(-1.0 / 0.0)
 <			-1
 
+		Can also be used as a |method|: >
+			Compute()->isinf()
+
 islocked({expr})					*islocked()* *E786*
 		The result is a Number, which is |TRUE| when {expr} is the
 		name of a locked variable.
@@ -5581,12 +5763,17 @@ items({dict})						*items()*
 		|List| item is a list with two items: the key of a {dict}
 		entry and the value of this entry.  The |List| is in arbitrary
 		order.
+		Can also be used as a |method|: >
+			mydict->items()
 
 isnan({expr})						*isnan()*
 		Return |TRUE| if {expr} is a float with value NaN. >
 			echo isnan(0.0 / 0.0)
 <			1
 
+		Can also be used as a |method|: >
+			Compute()->isnan()
+
 jobpid({job})						*jobpid()*
 		Return the PID (process id) of |job-id| {job}.
 
@@ -5714,6 +5901,9 @@ join({list} [, {sep}])					*join()*
 		converted into a string like with |string()|.
 		The opposite function is |split()|.
 
+		Can also be used as a |method|: >
+			mylist->join()
+
 json_decode({expr})					*json_decode()*
 		Convert {expr} from JSON object.  Accepts |readfile()|-style
 		list as the input, as well as regular string.  May output any
@@ -5744,8 +5934,10 @@ json_encode({expr})					*json_encode()*
 keys({dict})						*keys()*
 		Return a |List| with all the keys of {dict}.  The |List| is in
 		arbitrary order.
+		Can also be used as a |method|: >
+			mydict->keys()
 
-							*len()* *E701*
+<							*len()* *E701*
 len({expr})	The result is a Number, which is the length of the argument.
 		When {expr} is a String or a Number the length in bytes is
 		used, as with |strlen()|.
@@ -5756,7 +5948,10 @@ len({expr})	The result is a Number, which is the length of the argument.
 		|Dictionary| is returned.
 		Otherwise an error is given.
 
-						*libcall()* *E364* *E368*
+		Can also be used as a |method|: >
+			mylist->len()
+
+<						*libcall()* *E364* *E368*
 libcall({libname}, {funcname}, {argument})
 		Call function {funcname} in the run-time library {libname}
 		with single argument {argument}.
@@ -5881,6 +6076,8 @@ log({expr})						*log()*
 			:echo log(exp(5))
 <			5.0
 
+		Can also be used as a |method|: >
+			Compute()->log()
 
 log10({expr})						*log10()*
 		Return the logarithm of Float {expr} to base 10 as a |Float|.
@@ -5891,6 +6088,9 @@ log10({expr})						*log10()*
 			:echo log10(0.01)
 <			-2.0
 
+		Can also be used as a |method|: >
+			Compute()->log10()
+
 luaeval({expr}[, {expr}])
 		Evaluate Lua expression {expr} and return its result converted
 		to Vim data structures. See |lua-eval| for more details.
@@ -5939,6 +6139,8 @@ map({expr1}, {expr2})					*map()*
 		Funcref errors inside a function are ignored, unless it was
 		defined with the "abort" flag.
 
+		Can also be used as a |method|: >
+			mylist->map(expr2)
 
 maparg({name} [, {mode} [, {abbr} [, {dict}]]])			*maparg()*
 		When {dict} is omitted or zero: Return the rhs of mapping
@@ -6274,6 +6476,9 @@ max({expr})	Return the maximum value of all items in {expr}.
 		items in {expr} cannot be used as a Number this results in
                 an error.  An empty |List| or |Dictionary| results in zero.
 
+		Can also be used as a |method|: >
+			mylist->max()
+
 menu_get({path}, {modes})				*menu_get()*
 		Returns a |List| of |Dictionaries| describing |menus| (defined
 		by |:menu|, |:amenu|, …), including |hidden-menus|.
@@ -6328,7 +6533,10 @@ min({expr})	Return the minimum value of all items in {expr}.
 		items in {expr} cannot be used as a Number this results in
 		an error.  An empty |List| or |Dictionary| results in zero.
 
-							*mkdir()* *E739*
+		Can also be used as a |method|: >
+			mylist->min()
+
+<							*mkdir()* *E739*
 mkdir({name} [, {path} [, {prot}]])
 		Create directory {name}.
 		If {path} is "p" then intermediate directories are created as
@@ -6523,7 +6731,8 @@ or({expr}, {expr})					*or()*
 		to a number.  A List, Dict or Float argument causes an error.
 		Example: >
 			:let bits = or(bits, 0x80)
-
+<		Can also be used as a |method|: >
+			:let bits = bits->or(0x80)
 
 pathshorten({expr})					*pathshorten()*
 		Shorten directory names in the path {expr} and return the
@@ -6560,6 +6769,9 @@ pow({x}, {y})						*pow()*
 			:echo pow(32, 0.20)
 <			2.0
 
+		Can also be used as a |method|: >
+			Compute()->pow(3)
+
 prevnonblank({lnum})					*prevnonblank()*
 		Return the line number of the first line at or above {lnum}
 		that is not blank.  Example: >
@@ -6576,7 +6788,11 @@ printf({fmt}, {expr1} ...)				*printf()*
 <		May result in:
 			"  99: E42 asdfasdfasdfasdfasdfasdfasdfas" ~
 
-		Often used items are:
+		When used as a |method| the base is passed as the second
+		argument: >
+			Compute()->printf("result: %d")
+
+<		Often used items are:
 		  %s	string
 		  %6S	string right-aligned in 6 display cells
 		  %6s	string right-aligned in 6 bytes
@@ -7086,6 +7302,10 @@ remove({list}, {idx} [, {end}])				*remove()*
 		Example: >
 			:echo "last item: " . remove(mylist, -1)
 			:call remove(mylist, 0, 9)
+
+<		Can also be used as a |method|: >
+			mylist->remove(idx)
+
 remove({dict}, {key})
 		Remove the entry from {dict} with key {key} and return it.
 		Example: >
@@ -7112,6 +7332,8 @@ repeat({expr}, {count})					*repeat()*
 			:let longlist = repeat(['a', 'b'], 3)
 <		Results in ['a', 'b', 'a', 'b', 'a', 'b'].
 
+		Can also be used as a |method|: >
+			mylist->repeat(count)
 
 resolve({filename})					*resolve()* *E655*
 		On MS-Windows, when {filename} is a shortcut (a .lnk file),
@@ -7131,6 +7353,8 @@ reverse({list})	Reverse the order of items in {list} in-place.  Returns
 		{list}.
 		If you want a list to remain unmodified make a copy first: >
 			:let revlist = reverse(copy(mylist))
+<		Can also be used as a |method|: >
+			mylist->reverse()
 
 round({expr})							*round()*
 		Round off {expr} to the nearest integral value and return it
@@ -7145,6 +7369,9 @@ round({expr})							*round()*
 			echo round(-4.5)
 <			-5.0
 
+		Can also be used as a |method|: >
+			Compute()->round()
+
 rpcnotify({channel}, {event}[, {args}...])			*rpcnotify()*
 		Sends {event} to {channel} via |RPC| and returns immediately.
 		If {channel} is 0, the event is broadcast to all channels.
@@ -8121,6 +8348,8 @@ sin({expr})						*sin()*
 			:echo sin(-4.01)
 <			0.763301
 
+		Can also be used as a |method|: >
+			Compute()->sin()
 
 sinh({expr})						*sinh()*
 		Return the hyperbolic sine of {expr} as a |Float| in the range
@@ -8132,6 +8361,9 @@ sinh({expr})						*sinh()*
 			:echo sinh(-0.9)
 <			-1.026517
 
+		Can also be used as a |method|: >
+			Compute()->sinh()
+
 sockconnect({mode}, {address}, {opts})			 *sockconnect()*
 		Connect a socket to an address. If {mode} is "pipe" then
 		{address} should be the path of a named pipe. If {mode} is
@@ -8210,7 +8442,10 @@ sort({list} [, {func} [, {dict}]])			*sort()* *E702*
 		on numbers, text strings will sort next to each other, in the
 		same order as they were originally.
 
-		Also see |uniq()|.
+		Can also be used as a |method|: >
+			mylist->sort()
+
+<		Also see |uniq()|.
 
 		Example: >
 			func MyCompare(i1, i2)
@@ -8303,6 +8538,8 @@ split({expr} [, {pattern} [, {keepempty}]])			*split()*
 			:let items = split(line, ':', 1)
 <		The opposite function is |join()|.
 
+		Can also be used as a |method|: >
+			GetString()->split()
 
 sqrt({expr})						*sqrt()*
 		Return the non-negative square root of Float {expr} as a
@@ -8316,6 +8553,8 @@ sqrt({expr})						*sqrt()*
 <			nan
 		"nan" may be different, it depends on system libraries.
 
+		Can also be used as a |method|: >
+			Compute()->sqrt()
 
 stdioopen({opts})			 *stdioopen()*
 		With |--headless| this opens stdin and stdout as a |channel|.
@@ -8367,6 +8606,9 @@ str2float({expr})					*str2float()*
 		12.0.  You can strip out thousands separators with
 		|substitute()|: >
 			let f = str2float(substitute(text, ',', '', 'g'))
+<
+		Can also be used as a |method|: >
+			let f = text->substitute(',', '', 'g')->str2float()
 
 str2list({expr} [, {utf8}])				*str2list()*
 		Return a list containing the number values which represent
@@ -8381,12 +8623,18 @@ str2list({expr} [, {utf8}])				*str2list()*
 		properly: >
 			str2list("á")		returns [97, 769]
 
+<		Can also be used as a |method|: >
+			GetString()->str2list()
+
 str2nr({expr} [, {base}])				*str2nr()*
 		Convert string {expr} to a number.
 		{base} is the conversion base, it can be 2, 8, 10 or 16.
+
 		When {base} is omitted base 10 is used.  This also means that
 		a leading zero doesn't cause octal conversion to be used, as
-		with the default String to Number conversion.
+		with the default String to Number conversion.  Example: >
+			let nr = str2nr('123')
+<
 		When {base} is 16 a leading "0x" or "0X" is ignored.  With a
 		different base the result will be zero. Similarly, when {base}
 		is 8 a leading "0" is ignored, and when {base} is 2 a leading
@@ -8505,6 +8753,9 @@ string({expr})	Return {expr} converted to a String.  If {expr} is a Number,
 		method, use |msgpackdump()| or |json_encode()| if you need to
 		share data with other application.
 
+		Can also be used as a |method|: >
+			mylist->string()
+
 							*strlen()*
 strlen({expr})	The result is a Number, which is the length of the String
 		{expr} in bytes.
@@ -8514,6 +8765,9 @@ strlen({expr})	The result is a Number, which is the length of the String
 		|strchars()|.
 		Also see |len()|, |strdisplaywidth()| and |strwidth()|.
 
+		Can also be used as a |method|: >
+			GetString()->strlen()
+
 strpart({src}, {start} [, {len} [, {chars}]])			*strpart()*
 		The result is a String, which is part of {src}, starting from
 		byte {start}, with the byte length {len}.
@@ -8588,6 +8842,9 @@ strtrans({expr})					*strtrans()*
 <		This displays a newline in register a as "^@" instead of
 		starting a new line.
 
+		Can also be used as a |method|: >
+			GetString()->strtrans()
+
 strwidth({expr})					*strwidth()*
 		The result is a Number, which is the number of display cells
 		String {expr} occupies.  A Tab character is counted as one
@@ -8596,6 +8853,9 @@ strwidth({expr})					*strwidth()*
 		Ambiguous, this function's return value depends on 'ambiwidth'.
 		Also see |strlen()|, |strdisplaywidth()| and |strchars()|.
 
+		Can also be used as a |method|: >
+			GetString()->strwidth()
+
 submatch({nr} [, {list}])			*submatch()* *E935*
 		Only for an expression in a |:substitute| command or
 		substitute() function.
@@ -8663,6 +8923,9 @@ substitute({expr}, {pat}, {sub}, {flags})		*substitute()*
 		|submatch()| returns.  Example: >
 		   :echo substitute(s, '%\(\x\x\)', {m -> '0x' . m[1]}, 'g')
 
+<		Can also be used as a |method|: >
+			GetString()->substitute(pat, sub, flags)
+
 swapinfo({fname})					*swapinfo()*
 		The result is a dictionary, which holds information about the
 		swapfile {fname}. The available fields are:
@@ -8747,12 +9010,18 @@ synIDattr({synID}, {what} [, {mode}])			*synIDattr()*
 		cursor): >
 	:echo synIDattr(synIDtrans(synID(line("."), col("."), 1)), "fg")
 <
+		Can also be used as a |method|: >
+	:echo synID(line("."), col("."), 1)->synIDtrans()->synIDattr("fg")
+
 synIDtrans({synID})					*synIDtrans()*
 		The result is a Number, which is the translated syntax ID of
 		{synID}.  This is the syntax group ID of what is being used to
 		highlight the character.  Highlight links given with
 		":highlight link" are followed.
 
+		Can also be used as a |method|: >
+	:echo synID(line("."), col("."), 1)->synIDtrans()->synIDattr("fg")
+
 synconcealed({lnum}, {col})				*synconcealed()*
 		The result is a |List| with currently three items:
 		1. The first item in the list is 0 if the character at the
@@ -8849,6 +9118,8 @@ system({cmd} [, {input}])				*system()* *E677*
 		Unlike ":!cmd" there is no automatic check for changed files.
 		Use |:checktime| to force a check.
 
+		Can also be used as a |method|: >
+			:echo GetCmd()->system()
 
 systemlist({cmd} [, {input} [, {keepempty}]])		*systemlist()*
 		Same as |system()|, but returns a |List| with lines (parts of
@@ -8864,6 +9135,8 @@ systemlist({cmd} [, {input} [, {keepempty}]])		*systemlist()*
 <
 		Returns an empty string on error.
 
+		Can also be used as a |method|: >
+			:echo GetCmd()->systemlist()
 
 tabpagebuflist([{arg}])					*tabpagebuflist()*
 		The result is a |List|, where each item is the number of the
@@ -8987,6 +9260,8 @@ tan({expr})						*tan()*
 			:echo tan(-4.01)
 <			-1.181502
 
+		Can also be used as a |method|: >
+			Compute()->tan()
 
 tanh({expr})						*tanh()*
 		Return the hyperbolic tangent of {expr} as a |Float| in the
@@ -8998,6 +9273,8 @@ tanh({expr})						*tanh()*
 			:echo tanh(-1)
 <			-0.761594
 
+		Can also be used as a |method|: >
+			Compute()->tanh()
 
 							*timer_info()*
 timer_info([{id}])
@@ -9124,6 +9401,9 @@ trunc({expr})							*trunc()*
 			echo trunc(4.0)
 <			4.0
 
+		Can also be used as a |method|: >
+			Compute()->trunc()
+
 type({expr})							*type()*
 		The result is a Number representing the type of {expr}.
 		Instead of using the number directly, it is better to use the
@@ -9150,6 +9430,9 @@ type({expr})							*type()*
 <               To check if the v:t_ variables exist use this: >
                         :if exists('v:t_number')
 
+<		Can also be used as a |method|: >
+			mylist->type()
+
 undofile({name})					*undofile()*
 		Return the name of the undo file that would be used for a file
 		with name {name} when writing.  This uses the 'undodir'
@@ -9212,10 +9495,15 @@ uniq({list} [, {func} [, {dict}]])			*uniq()* *E882*
 <		The default compare function uses the string representation of
 		each item.  For the use of {func} and {dict} see |sort()|.
 
+		Can also be used as a |method|: >
+			mylist->uniq()
+
 values({dict})						*values()*
 		Return a |List| with all the values of {dict}.  The |List| is
 		in arbitrary order.
 
+		Can also be used as a |method|: >
+			mydict->values()
 
 virtcol({expr})						*virtcol()*
 		The result is a Number, which is the screen column of the file
@@ -9392,6 +9680,9 @@ winbufnr({nr})	The result is a Number, which is the number of the buffer
 		When window {nr} doesn't exist, -1 is returned.
 		Example: >
   :echo "The file in the current window is " . bufname(winbufnr(0))
+<
+		Can also be used as a |method|: >
+			FindWindow()->winbufnr()->bufname()
 <
 							*wincol()*
 wincol()	The result is a Number, which is the virtual column of the
@@ -9606,6 +9897,8 @@ xor({expr}, {expr})					*xor()*
 		to a number.  A List, Dict or Float argument causes an error.
 		Example: >
 			:let bits = xor(bits, 0x80)
+<		Can also be used as a |method|: >
+			:let bits = bits->xor(0x80)
 <
 
 
@@ -9943,7 +10236,9 @@ This function can then be called with: >
 The recursiveness of user functions is restricted with the |'maxfuncdepth'|
 option.
 
-It is also possible to use `:eval`.  It does not support a range.
+It is also possible to use `:eval`.  It does not support a range, but does
+allow for method chaining, e.g.: >
+	eval GetList()->Filter()->append('$')
 
 
 AUTOMATICALLY LOADING FUNCTIONS ~
@@ -10686,7 +10981,7 @@ text...
 <
 							*:eval*
 :eval {expr}		Evaluate {expr} and discard the result.  Example: >
-				:eval append(Filter(Getlist()), '$')
+				:eval Getlist()->Filter()->append('$')
 
 <			The expression is supposed to have a side effect,
 			since the resulting value is not used.  In the example

runtime/doc/lua.txt

@@ -391,6 +391,10 @@ where the args are converted to Lua values. The expression >
 is equivalent to the Lua chunk >
     return somemod.func(...)
 
+The `v:lua` prefix may be used to call Lua functions as |method|s. For
+example: >
+    arg1->v:lua.somemod.func(arg2)
+
 You can use `v:lua` in "func" options like 'tagfunc', 'omnifunc', etc.
 For example consider the following Lua omnifunc handler: >
 

runtime/doc/testing.txt

@@ -53,6 +53,9 @@ assert_beeps({cmd})					*assert_beeps()*
 		Also see |assert_fails()|, |assert_nobeep()| and
 		|assert-return|.
 
+		Can also be used as a |method|: >
+			GetCmd()->assert_beeps()
+<
 							*assert_equal()*
 assert_equal({expected}, {actual} [, {msg}])
 		When {expected} and {actual} are not equal an error message is
@@ -69,7 +72,10 @@ assert_equal({expected}, {actual} [, {msg}])
 <		Will result in a string to be added to |v:errors|:
 	test.vim line 12: Expected 'foo' but got 'bar' ~
 
-							*assert_equalfile()*
+		Can also be used as a |method|: >
+			mylist->assert_equal([1, 2, 3])
+
+<							*assert_equalfile()*
 assert_equalfile({fname-one}, {fname-two})
 		When the files {fname-one} and {fname-two} do not contain
 		exactly the same text an error message is added to |v:errors|.
@@ -77,6 +83,9 @@ assert_equalfile({fname-one}, {fname-two})
 		When {fname-one} or {fname-two} does not exist the error will
 		mention that.
 
+		Can also be used as a |method|: >
+			GetLog()->assert_equalfile('expected.log')
+
 assert_exception({error} [, {msg}])			*assert_exception()*
 		When v:exception does not contain the string {error} an error
 		message is added to |v:errors|.  Also see |assert-return|.
@@ -97,6 +106,9 @@ assert_fails({cmd} [, {error} [, {msg}]])			*assert_fails()*
 		Note that beeping is not considered an error, and some failing
 		commands only beep.  Use |assert_beeps()| for those.
 
+		Can also be used as a |method|: >
+			GetCmd()->assert_fails('E99:')
+
 assert_false({actual} [, {msg}])				*assert_false()*
 		When {actual} is not false an error message is added to
 		|v:errors|, like with |assert_equal()|.
@@ -106,6 +118,9 @@ assert_false({actual} [, {msg}])				*assert_false()*
 		When {msg} is omitted an error in the form
 		"Expected False but got {actual}" is produced.
 
+		Can also be used as a |method|: >
+			GetResult()->assert_false()
+
 assert_inrange({lower}, {upper}, {actual} [, {msg}])	 *assert_inrange()*
 		This asserts number and |Float| values.  When {actual}  is lower
 		than {lower} or higher than {upper} an error message is added
@@ -134,6 +149,9 @@ assert_match({pattern}, {actual} [, {msg}])
 <		Will result in a string to be added to |v:errors|:
 	test.vim line 12: Pattern '^f.*o$' does not match 'foobar' ~
 
+		Can also be used as a |method|: >
+			getFile()->assert_match('foo.*')
+<
 assert_nobeep({cmd})					*assert_nobeep()*
 		Run {cmd} and add an error message to |v:errors| if it
 		produces a beep or visual bell.
@@ -145,16 +163,27 @@ assert_notequal({expected}, {actual} [, {msg}])
 		|v:errors| when {expected} and {actual} are equal.
 		Also see |assert-return|.
 
-							*assert_notmatch()*
+		Can also be used as a |method|: >
+			mylist->assert_notequal([1, 2, 3])
+
+<							*assert_notmatch()*
 assert_notmatch({pattern}, {actual} [, {msg}])
 		The opposite of `assert_match()`: add an error message to
 		|v:errors| when {pattern} matches {actual}.
 		Also see |assert-return|.
 
+		Can also be used as a |method|: >
+			getFile()->assert_notmatch('bar.*')
+
+
 assert_report({msg})					*assert_report()*
 		Report a test failure directly, using {msg}.
 		Always returns one.
 
+		Can also be used as a |method|: >
+			GetMessage()->assert_report()
+
+
 assert_true({actual} [, {msg}])				*assert_true()*
 		When {actual} is not true an error message is added to
 		|v:errors|, like with |assert_equal()|.
@@ -164,5 +193,8 @@ assert_true({actual} [, {msg}])				*assert_true()*
 		When {msg} is omitted an error in the form "Expected True but
 		got {actual}" is produced.
 
+		Can also be used as a |method|: >
+			GetResult()->assert_true()
+<
 
  vim:tw=78:ts=8:noet:ft=help:norl:

src/nvim/api/vim.c

@@ -608,12 +608,15 @@ static Object _call_function(String fn, Array args, dict_T *self, Error *err)
   recursive++;
   try_start();
   typval_T rettv;
-  int dummy;
+  funcexe_T funcexe = FUNCEXE_INIT;
+  funcexe.firstline = curwin->w_cursor.lnum;
+  funcexe.lastline = curwin->w_cursor.lnum;
+  funcexe.evaluate = true;
+  funcexe.selfdict = self;
   // call_func() retval is deceptive, ignore it.  Instead we set `msg_list`
   // (see above) to capture abort-causing non-exception errors.
   (void)call_func((char_u *)fn.data, (int)fn.size, &rettv, (int)args.size,
-                  vim_args, NULL, curwin->w_cursor.lnum, curwin->w_cursor.lnum,
+                  vim_args, &funcexe);
-                  &dummy, true, NULL, self);
   if (!try_end(err)) {
     rv = vim_to_object(&rettv);
   }

src/nvim/eval.c

@@ -65,6 +65,8 @@ static char *e_missbrac = N_("E111: Missing ']'");
 static char *e_dictrange = N_("E719: Cannot use [:] with a Dictionary");
 static char *e_illvar = N_("E461: Illegal variable name: %s");
 static char *e_cannot_mod = N_("E995: Cannot modify existing variable");
+static char *e_nowhitespace
+    = N_("E274: No white space allowed before parenthesis");
 static char *e_invalwindow = N_("E957: Invalid window number");
 static char *e_lock_unlock = N_("E940: Cannot lock or unlock variable %s");
 
@@ -736,15 +738,15 @@ int eval_expr_typval(const typval_T *expr, typval_T *argv,
                      int argc, typval_T *rettv)
   FUNC_ATTR_NONNULL_ARG(1, 2, 4)
 {
-  int dummy;
+  funcexe_T funcexe = FUNCEXE_INIT;
 
   if (expr->v_type == VAR_FUNC) {
     const char_u *const s = expr->vval.v_string;
     if (s == NULL || *s == NUL) {
       return FAIL;
     }
-    if (call_func(s, -1, rettv, argc, argv, NULL,
+    funcexe.evaluate = true;
-                  0L, 0L, &dummy, true, NULL, NULL) == FAIL) {
+    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL) {
       return FAIL;
     }
   } else if (expr->v_type == VAR_PARTIAL) {
@@ -753,8 +755,9 @@ int eval_expr_typval(const typval_T *expr, typval_T *argv,
     if (s == NULL || *s == NUL) {
       return FAIL;
     }
-    if (call_func(s, -1, rettv, argc, argv, NULL,
+    funcexe.evaluate = true;
-                  0L, 0L, &dummy, true, partial, NULL) == FAIL) {
+    funcexe.partial = partial;
+    if (call_func(s, -1, rettv, argc, argv, &funcexe) == FAIL) {
       return FAIL;
     }
   } else {
@@ -1050,7 +1053,6 @@ int call_vim_function(
 )
   FUNC_ATTR_NONNULL_ALL
 {
-  int doesrange;
   int ret;
   int len = (int)STRLEN(func);
   partial_T *pt = NULL;
@@ -1066,9 +1068,12 @@ int call_vim_function(
   }
 
   rettv->v_type = VAR_UNKNOWN;  // tv_clear() uses this.
-  ret = call_func(func, len, rettv, argc, argv, NULL,
+  funcexe_T funcexe = FUNCEXE_INIT;
-                  curwin->w_cursor.lnum, curwin->w_cursor.lnum,
+  funcexe.firstline = curwin->w_cursor.lnum;
-                  &doesrange, true, pt, NULL);
+  funcexe.lastline = curwin->w_cursor.lnum;
+  funcexe.evaluate = true;
+  funcexe.partial = pt;
+  ret = call_func(func, len, rettv, argc, argv, &funcexe);
 
 fail:
   if (ret == FAIL) {
@@ -1724,7 +1729,9 @@ static const char *list_arg_vars(exarg_T *eap, const char *arg, int *first)
         } else {
           // handle d.key, l[idx], f(expr)
           const char *const arg_subsc = arg;
-          if (handle_subscript(&arg, &tv, true, true) == FAIL) {
+          if (handle_subscript(&arg, &tv, true, true, (const char_u *)name,
+                               (const char_u **)&name)
+              == FAIL) {
             error = true;
           } else {
             if (arg == arg_subsc && len == 2 && name[1] == ':') {
@@ -3142,6 +3149,65 @@ static int pattern_match(char_u *pat, char_u *text, bool ic)
   return matches;
 }
 
+/// Handle a name followed by "(".  Both for just "name(arg)" and for
+/// "expr->name(arg)".
+//
+/// @param arg  Points to "(", will be advanced
+/// @param basetv  "expr" for "expr->name(arg)"
+//
+/// @return OK or FAIL.
+static int eval_func(char_u **const arg, char_u *const name, const int name_len,
+                     typval_T *const rettv, const bool evaluate,
+                     typval_T *const basetv)
+  FUNC_ATTR_NONNULL_ARG(1, 2, 4)
+{
+  char_u *s = name;
+  int len = name_len;
+
+  if (!evaluate) {
+    check_vars((const char *)s, len);
+  }
+
+  // If "s" is the name of a variable of type VAR_FUNC
+  // use its contents.
+  partial_T *partial;
+  s = deref_func_name((const char *)s, &len, &partial, !evaluate);
+
+  // Need to make a copy, in case evaluating the arguments makes
+  // the name invalid.
+  s = xmemdupz(s, len);
+
+  // Invoke the function.
+  funcexe_T funcexe = FUNCEXE_INIT;
+  funcexe.firstline = curwin->w_cursor.lnum;
+  funcexe.lastline = curwin->w_cursor.lnum;
+  funcexe.evaluate = evaluate;
+  funcexe.partial = partial;
+  funcexe.basetv = basetv;
+  int ret = get_func_tv(s, len, rettv, arg, &funcexe);
+
+  xfree(s);
+
+  // If evaluate is false rettv->v_type was not set in
+  // get_func_tv, but it's needed in handle_subscript() to parse
+  // what follows. So set it here.
+  if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(') {
+    rettv->vval.v_string = (char_u *)tv_empty_string;
+    rettv->v_type = VAR_FUNC;
+  }
+
+  // Stop the expression evaluation when immediately
+  // aborting on error, or when an interrupt occurred or
+  // an exception was thrown but not caught.
+  if (evaluate && aborting()) {
+    if (ret == OK) {
+      tv_clear(rettv);
+    }
+    ret = FAIL;
+  }
+  return ret;
+}
+
 // TODO(ZyX-I): move to eval/expressions
 
 /*
@@ -3161,6 +3227,8 @@ int eval0(char_u *arg, typval_T *rettv, char_u **nextcmd, int evaluate)
 {
   int ret;
   char_u      *p;
+  const int did_emsg_before = did_emsg;
+  const int called_emsg_before = called_emsg;
 
   p = skipwhite(arg);
   ret = eval1(&p, rettv, evaluate);
@@ -3170,8 +3238,10 @@ int eval0(char_u *arg, typval_T *rettv, char_u **nextcmd, int evaluate)
     }
     // Report the invalid expression unless the expression evaluation has
     // been cancelled due to an aborting error, an interrupt, or an
-    // exception.
+    // exception, or we already gave a more specific error.
-    if (!aborting()) {
+    // Also check called_emsg for when using assert_fails().
+    if (!aborting() && did_emsg == did_emsg_before
+        && called_emsg == called_emsg_before) {
       emsgf(_(e_invexpr2), arg);
     }
     ret = FAIL;
@@ -3801,6 +3871,7 @@ static int eval6(char_u **arg, typval_T *rettv, int evaluate, int want_string)
 //  + in front  unary plus (ignored)
 //  trailing []  subscript in String or List
 //  trailing .name entry in Dictionary
+//  trailing ->name()  method call
 //
 // "arg" must point to the first non-white of the expression.
 // "arg" is advanced to the next non-white after the recognized expression.
@@ -3816,7 +3887,7 @@ static int eval7(
   varnumber_T n;
   int len;
   char_u *s;
-  char_u      *start_leader, *end_leader;
+  const char_u *start_leader, *end_leader;
   int ret = OK;
   char_u *alias;
 
@@ -3968,44 +4039,7 @@ static int eval7(
       ret = FAIL;
     } else {
       if (**arg == '(') {               // recursive!
-        partial_T *partial;
+        ret = eval_func(arg, s, len, rettv, evaluate, NULL);
-
-        if (!evaluate) {
-          check_vars((const char *)s, len);
-        }
-
-        // If "s" is the name of a variable of type VAR_FUNC
-        // use its contents.
-        s = deref_func_name((const char *)s, &len, &partial, !evaluate);
-
-        // Need to make a copy, in case evaluating the arguments makes
-        // the name invalid.
-        s = xmemdupz(s, len);
-
-        // Invoke the function.
-        ret = get_func_tv(s, len, rettv, arg,
-                          curwin->w_cursor.lnum, curwin->w_cursor.lnum,
-                          &len, evaluate, partial, NULL);
-
-        xfree(s);
-
-        // If evaluate is false rettv->v_type was not set in
-        // get_func_tv, but it's needed in handle_subscript() to parse
-        // what follows. So set it here.
-        if (rettv->v_type == VAR_UNKNOWN && !evaluate && **arg == '(') {
-          rettv->vval.v_string = (char_u *)tv_empty_string;
-          rettv->v_type = VAR_FUNC;
-        }
-
-        // Stop the expression evaluation when immediately
-        // aborting on error, or when an interrupt occurred or
-        // an exception was thrown but not caught.
-        if (evaluate && aborting()) {
-          if (ret == OK) {
-            tv_clear(rettv);
-          }
-          ret = FAIL;
-        }
       } else if (evaluate) {
         ret = get_var_tv((const char *)s, len, rettv, NULL, true, false);
       } else {
@@ -4019,13 +4053,28 @@ static int eval7(
   *arg = skipwhite(*arg);
 
   // Handle following '[', '(' and '.' for expr[expr], expr.name,
-  // expr(expr).
+  // expr(expr), expr->name(expr)
   if (ret == OK) {
-    ret = handle_subscript((const char **)arg, rettv, evaluate, true);
+    ret = handle_subscript((const char **)arg, rettv, evaluate, true,
+                           start_leader, &end_leader);
   }
 
   // Apply logical NOT and unary '-', from right to left, ignore '+'.
   if (ret == OK && evaluate && end_leader > start_leader) {
+    ret = eval7_leader(rettv, start_leader, &end_leader);
+  }
+  return ret;
+}
+
+/// Apply the leading "!" and "-" before an eval7 expression to "rettv".
+/// Adjusts "end_leaderp" until it is at "start_leader".
+/// @return OK on success, FAIL on failure.
+static int eval7_leader(typval_T *const rettv, const char_u *const start_leader,
+                        const char_u **const end_leaderp)
+  FUNC_ATTR_NONNULL_ALL
+{
+  const char_u *end_leader = *end_leaderp;
+  int ret = OK;
   bool error = false;
   varnumber_T val = 0;
   float_T f = 0.0;
@@ -4040,7 +4089,7 @@ static int eval7(
     ret = FAIL;
   } else {
     while (end_leader > start_leader) {
-        --end_leader;
+      end_leader--;
       if (*end_leader == '!') {
         if (rettv->v_type == VAR_FLOAT) {
           f = !f;
@@ -4064,6 +4113,170 @@ static int eval7(
       rettv->vval.v_number = val;
     }
   }
+
+  *end_leaderp = end_leader;
+  return ret;
+}
+
+/// Call the function referred to in "rettv".
+/// @param lua_funcname  If `rettv` refers to a v:lua function, this must point
+///                      to the name of the Lua function to call (after the
+///                      "v:lua." prefix).
+/// @return OK on success, FAIL on failure.
+static int call_func_rettv(char_u **const arg,
+                           typval_T *const rettv,
+                           const bool evaluate,
+                           dict_T *const selfdict,
+                           typval_T *const basetv,
+                           const char_u *const lua_funcname)
+  FUNC_ATTR_NONNULL_ARG(1, 2)
+{
+  partial_T *pt = NULL;
+  typval_T functv;
+  const char_u *funcname;
+  bool is_lua = false;
+
+  // need to copy the funcref so that we can clear rettv
+  if (evaluate) {
+    functv = *rettv;
+    rettv->v_type = VAR_UNKNOWN;
+
+    // Invoke the function.  Recursive!
+    if (functv.v_type == VAR_PARTIAL) {
+      pt = functv.vval.v_partial;
+      is_lua = is_luafunc(pt);
+      funcname = is_lua ? lua_funcname : partial_name(pt);
+    } else {
+      funcname = functv.vval.v_string;
+    }
+  } else {
+    funcname = (char_u *)"";
+  }
+
+  funcexe_T funcexe = FUNCEXE_INIT;
+  funcexe.firstline = curwin->w_cursor.lnum;
+  funcexe.lastline = curwin->w_cursor.lnum;
+  funcexe.evaluate = evaluate;
+  funcexe.partial = pt;
+  funcexe.selfdict = selfdict;
+  funcexe.basetv = basetv;
+  const int ret = get_func_tv(funcname, is_lua ? *arg - funcname : -1, rettv,
+                              (char_u **)arg, &funcexe);
+
+  // Clear the funcref afterwards, so that deleting it while
+  // evaluating the arguments is possible (see test55).
+  if (evaluate) {
+    tv_clear(&functv);
+  }
+
+  return ret;
+}
+
+/// Evaluate "->method()".
+/// @param verbose  if true, give error messages.
+/// @note "*arg" points to the '-'.
+/// @return FAIL or OK. @note "*arg" is advanced to after the ')'.
+static int eval_lambda(char_u **const arg, typval_T *const rettv,
+                       const bool evaluate, const bool verbose)
+  FUNC_ATTR_NONNULL_ALL
+{
+  // Skip over the ->.
+  *arg += 2;
+  typval_T base = *rettv;
+  rettv->v_type = VAR_UNKNOWN;
+
+  int ret = get_lambda_tv(arg, rettv, evaluate);
+  if (ret == NOTDONE) {
+    return FAIL;
+  } else if (**arg != '(') {
+    if (verbose) {
+      if (*skipwhite(*arg) == '(') {
+        EMSG(_(e_nowhitespace));
+      } else {
+        EMSG2(_(e_missingparen), "lambda");
+      }
+    }
+    tv_clear(rettv);
+    ret = FAIL;
+  } else {
+    ret = call_func_rettv(arg, rettv, evaluate, NULL, &base, NULL);
+  }
+
+  // Clear the funcref afterwards, so that deleting it while
+  // evaluating the arguments is possible (see test55).
+  if (evaluate) {
+    tv_clear(&base);
+  }
+
+  return ret;
+}
+
+/// Evaluate "->method()" or "->v:lua.method()".
+/// @note "*arg" points to the '-'.
+/// @return FAIL or OK. "*arg" is advanced to after the ')'.
+static int eval_method(char_u **const arg, typval_T *const rettv,
+                       const bool evaluate, const bool verbose)
+  FUNC_ATTR_NONNULL_ALL
+{
+  // Skip over the ->.
+  *arg += 2;
+  typval_T base = *rettv;
+  rettv->v_type = VAR_UNKNOWN;
+
+  // Locate the method name.
+  int len;
+  char_u *name = *arg;
+  char_u *lua_funcname = NULL;
+  if (STRNCMP(name, "v:lua.", 6) == 0) {
+    lua_funcname = name + 6;
+    *arg = (char_u *)skip_luafunc_name((const char *)lua_funcname);
+    *arg = skipwhite(*arg);  // to detect trailing whitespace later
+    len = *arg - lua_funcname;
+  } else {
+    char_u *alias;
+    len = get_name_len((const char **)arg, (char **)&alias, evaluate, true);
+    if (alias != NULL) {
+      name = alias;
+    }
+  }
+
+  int ret;
+  if (len <= 0) {
+    if (verbose) {
+      if (lua_funcname == NULL) {
+        EMSG(_("E260: Missing name after ->"));
+      } else {
+        EMSG2(_(e_invexpr2), name);
+      }
+    }
+    ret = FAIL;
+  } else {
+    if (**arg != '(') {
+      if (verbose) {
+        EMSG2(_(e_missingparen), name);
+      }
+      ret = FAIL;
+    } else if (ascii_iswhite((*arg)[-1])) {
+      if (verbose) {
+        EMSG(_(e_nowhitespace));
+      }
+      ret = FAIL;
+    } else if (lua_funcname != NULL) {
+      if (evaluate) {
+        rettv->v_type = VAR_PARTIAL;
+        rettv->vval.v_partial = vvlua_partial;
+        rettv->vval.v_partial->pt_refcount++;
+      }
+      ret = call_func_rettv(arg, rettv, evaluate, NULL, &base, lua_funcname);
+    } else {
+      ret = eval_func(arg, name, len, rettv, evaluate, &base);
+    }
+  }
+
+  // Clear the funcref afterwards, so that deleting it while
+  // evaluating the arguments is possible (see test55).
+  if (evaluate) {
+    tv_clear(&base);
   }
 
   return ret;
@@ -7255,10 +7468,12 @@ bool callback_call(Callback *const callback, const int argcount_in,
       abort();
   }
 
-  int dummy;
+  funcexe_T funcexe = FUNCEXE_INIT;
-  return call_func(name, -1, rettv, argcount_in, argvars_in,
+  funcexe.firstline = curwin->w_cursor.lnum;
-                   NULL, curwin->w_cursor.lnum, curwin->w_cursor.lnum, &dummy,
+  funcexe.lastline = curwin->w_cursor.lnum;
-                   true, partial, NULL);
+  funcexe.evaluate = true;
+  funcexe.partial = partial;
+  return call_func(name, -1, rettv, argcount_in, argvars_in, &funcexe);
 }
 
 static bool set_ref_in_callback(Callback *callback, int copyID,
@@ -8393,13 +8608,23 @@ static bool tv_is_luafunc(typval_T *tv)
   return tv->v_type == VAR_PARTIAL && is_luafunc(tv->vval.v_partial);
 }
 
-/// check the function name after "v:lua."
+/// Skips one character past the end of the name of a v:lua function.
-int check_luafunc_name(const char *str, bool paren)
+/// @param p  Pointer to the char AFTER the "v:lua." prefix.
+/// @return Pointer to the char one past the end of the function's name.
+const char *skip_luafunc_name(const char *p)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  const char *p = str;
   while (ASCII_ISALNUM(*p) || *p == '_' || *p == '.' || *p == '\'') {
     p++;
   }
+  return p;
+}
+
+/// check the function name after "v:lua."
+int check_luafunc_name(const char *const str, const bool paren)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
+{
+  const char *const p = skip_luafunc_name(str);
   if (*p != (paren ? '(' : NUL)) {
     return 0;
   } else {
@@ -8407,24 +8632,26 @@ int check_luafunc_name(const char *str, bool paren)
   }
 }
 
-/// Handle expr[expr], expr[expr:expr] subscript and .name lookup.
+/// Handle:
-/// Also handle function call with Funcref variable: func(expr)
+/// - expr[expr], expr[expr:expr] subscript
-/// Can all be combined: dict.func(expr)[idx]['func'](expr)
+/// - ".name" lookup
+/// - function call with Funcref variable: func(expr)
+/// - method call: var->method()
+///
+/// Can all be combined in any order: dict.func(expr)[idx]['func'](expr)->len()
 int
 handle_subscript(
     const char **const arg,
     typval_T *rettv,
     int evaluate,                      // do more than finding the end
-    int verbose                    // give error messages
+    int verbose,                       // give error messages
+    const char_u *const start_leader,  // start of '!' and '-' prefixes
+    const char_u **const end_leaderp   // end of '!' and '-' prefixes
 )
 {
   int ret = OK;
   dict_T *selfdict = NULL;
-  const char_u *s;
+  const char_u *lua_funcname = NULL;
-  int len;
-  typval_T functv;
-  int slen = 0;
-  bool lua = false;
 
   if (tv_is_luafunc(rettv)) {
     if (**arg != '.') {
@@ -8433,55 +8660,28 @@ handle_subscript(
     } else {
       (*arg)++;
 
-      lua = true;
+      lua_funcname = (char_u *)(*arg);
-      s = (char_u *)(*arg);
+      const int len = check_luafunc_name(*arg, true);
-      slen = check_luafunc_name(*arg, true);
+      if (len == 0) {
-      if (slen == 0) {
         tv_clear(rettv);
         ret = FAIL;
       }
-      (*arg) += slen;
+      (*arg) += len;
     }
   }
 
-
   while (ret == OK
-         && (**arg == '['
+         && (((**arg == '[' || (**arg == '.' && rettv->v_type == VAR_DICT)
-             || (**arg == '.' && rettv->v_type == VAR_DICT)
                || (**arg == '(' && (!evaluate || tv_is_func(*rettv))))
-         && !ascii_iswhite(*(*arg - 1))) {
+              && !ascii_iswhite(*(*arg - 1)))
+             || (**arg == '-' && (*arg)[1] == '>'))) {
     if (**arg == '(') {
-      partial_T *pt = NULL;
+      ret = call_func_rettv((char_u **)arg, rettv, evaluate, selfdict, NULL,
-      // need to copy the funcref so that we can clear rettv
+                            lua_funcname);
-      if (evaluate) {
-        functv = *rettv;
-        rettv->v_type = VAR_UNKNOWN;
 
-        // Invoke the function.  Recursive!
+      // Stop the expression evaluation when immediately aborting on
-        if (functv.v_type == VAR_PARTIAL) {
+      // error, or when an interrupt occurred or an exception was thrown
-          pt = functv.vval.v_partial;
+      // but not caught.
-          if (!lua) {
-            s = partial_name(pt);
-          }
-        } else {
-          s = functv.vval.v_string;
-        }
-      } else {
-        s = (char_u *)"";
-      }
-      ret = get_func_tv(s, lua ? slen : -1, rettv, (char_u **)arg,
-                        curwin->w_cursor.lnum, curwin->w_cursor.lnum,
-                        &len, evaluate, pt, selfdict);
-
-      // Clear the funcref afterwards, so that deleting it while
-      // evaluating the arguments is possible (see test55).
-      if (evaluate) {
-        tv_clear(&functv);
-      }
-
-      /* Stop the expression evaluation when immediately aborting on
-       * error, or when an interrupt occurred or an exception was thrown
-       * but not caught. */
       if (aborting()) {
         if (ret == OK) {
           tv_clear(rettv);
@@ -8490,6 +8690,21 @@ handle_subscript(
       }
       tv_dict_unref(selfdict);
       selfdict = NULL;
+    } else if (**arg == '-') {
+      // Expression "-1.0->method()" applies the leader "-" before
+      // applying ->.
+      if (evaluate && *end_leaderp > start_leader) {
+        ret = eval7_leader(rettv, start_leader, end_leaderp);
+      }
+      if (ret == OK) {
+        if ((*arg)[2] == '{') {
+          // expr->{lambda}()
+          ret = eval_lambda((char_u **)arg, rettv, evaluate, verbose);
+        } else {
+          // expr->name()
+          ret = eval_method((char_u **)arg, rettv, evaluate, verbose);
+        }
+      }
     } else {  // **arg == '[' || **arg == '.'
       tv_dict_unref(selfdict);
       if (rettv->v_type == VAR_DICT) {
@@ -9274,6 +9489,7 @@ void ex_echo(exarg_T *eap)
   bool atstart = true;
   bool need_clear = true;
   const int did_emsg_before = did_emsg;
+  const int called_emsg_before = called_emsg;
 
   if (eap->skip)
     ++emsg_skip;
@@ -9288,7 +9504,8 @@ void ex_echo(exarg_T *eap)
         // Report the invalid expression unless the expression evaluation
         // has been cancelled due to an aborting error, an interrupt, or an
         // exception.
-        if (!aborting() && did_emsg == did_emsg_before) {
+        if (!aborting() && did_emsg == did_emsg_before
+            && called_emsg == called_emsg_before) {
           EMSG2(_(e_invexpr2), p);
         }
         need_clr_eos = false;
@@ -10409,19 +10626,11 @@ typval_T eval_call_provider(char *provider, char *method, list_T *arguments,
   typval_T rettv = { .v_type = VAR_UNKNOWN, .v_lock = VAR_UNLOCKED };
   tv_list_ref(arguments);
 
-  int dummy;
+  funcexe_T funcexe = FUNCEXE_INIT;
-  (void)call_func((const char_u *)func,
+  funcexe.firstline = curwin->w_cursor.lnum;
-                  name_len,
+  funcexe.lastline = curwin->w_cursor.lnum;
-                  &rettv,
+  funcexe.evaluate = true;
-                  2,
+  (void)call_func((const char_u *)func, name_len, &rettv, 2, argvars, &funcexe);
-                  argvars,
-                  NULL,
-                  curwin->w_cursor.lnum,
-                  curwin->w_cursor.lnum,
-                  &dummy,
-                  true,
-                  NULL,
-                  NULL);
 
   tv_list_unref(arguments);
   // Restore caller scope information
@@ -10779,7 +10988,9 @@ bool var_exists(const char *var)
     n = get_var_tv(name, len, &tv, NULL, false, true) == OK;
     if (n) {
       // Handle d.key, l[idx], f(expr).
-      n = handle_subscript(&var, &tv, true, false) == OK;
+      n = handle_subscript(&var, &tv, true, false, (const char_u *)name,
+                           (const char_u **)&name)
+          == OK;
       if (n) {
         tv_clear(&tv);
       }

src/nvim/eval.lua

@@ -5,6 +5,9 @@
 -- args  Number of arguments, list with maximum and minimum number of arguments
 --       or list with a minimum number of arguments only. Defaults to zero
 --       arguments.
+-- base  For methods: the argument to use as the base argument (1-indexed):
+--       base->method()
+--       Defaults to BASE_NONE (function cannot be used as a method).
 -- func  Name of the C function which implements the VimL function. Defaults to
 --       `f_{funcname}`.
 
@@ -12,111 +15,115 @@ local varargs = function(nr)
   return {nr}
 end
 
+-- Usable with the base key: use the last function argument as the method base.
+-- Value is from funcs.h file. "BASE_" prefix is omitted.
+local LAST = "BASE_LAST"
+
 return {
   funcs={
-    abs={args=1},
+    abs={args=1, base=1},
-    acos={args=1, func="float_op_wrapper", data="&acos"},  -- WJMc
+    acos={args=1, base=1, func="float_op_wrapper", data="&acos"},  -- WJMc
-    add={args=2},
+    add={args=2, base=1},
-    ['and']={args=2},
+    ['and']={args=2, base=1},
     api_info={},
-    append={args=2},
+    append={args=2, base=LAST},
-    appendbufline={args=3},
+    appendbufline={args=3, base=LAST},
     argc={args={0, 1}},
     argidx={},
     arglistid={args={0, 2}},
     argv={args={0, 2}},
-    asin={args=1, func="float_op_wrapper", data="&asin"},  -- WJMc
+    asin={args=1, base=1, func="float_op_wrapper", data="&asin"},  -- WJMc
-    assert_beeps={args={1}},
+    assert_beeps={args={1}, base=1},
-    assert_equal={args={2, 3}},
+    assert_equal={args={2, 3}, base=2},
-    assert_equalfile={args={2, 3}},
+    assert_equalfile={args={2, 3}, base=1},
     assert_exception={args={1, 2}},
-    assert_fails={args={1, 3}},
+    assert_fails={args={1, 3}, base=1},
-    assert_false={args={1, 2}},
+    assert_false={args={1, 2}, base=1},
-    assert_inrange={args={3, 4}},
+    assert_inrange={args={3, 4}, base=3},
-    assert_match={args={2, 3}},
+    assert_match={args={2, 3}, base=2},
     assert_nobeep={args={1}},
-    assert_notequal={args={2, 3}},
+    assert_notequal={args={2, 3}, base=2},
-    assert_notmatch={args={2, 3}},
+    assert_notmatch={args={2, 3}, base=2},
-    assert_report={args=1},
+    assert_report={args=1, base=1},
-    assert_true={args={1, 2}},
+    assert_true={args={1, 2}, base=1},
-    atan={args=1, func="float_op_wrapper", data="&atan"},
+    atan={args=1, base=1, func="float_op_wrapper", data="&atan"},
-    atan2={args=2},
+    atan2={args=2, base=1},
     browse={args=4},
     browsedir={args=2},
-    bufadd={args=1},
+    bufadd={args=1, base=1},
-    bufexists={args=1},
+    bufexists={args=1, base=1},
-    buffer_exists={args=1, func='f_bufexists'},  -- obsolete
+    buffer_exists={args=1, base=1, func='f_bufexists'},  -- obsolete
     buffer_name={args={0, 1}, func='f_bufname'},  -- obsolete
     buffer_number={args={0, 1}, func='f_bufnr'},  -- obsolete
-    buflisted={args=1},
+    buflisted={args=1, base=1},
-    bufload={args=1},
+    bufload={args=1, base=1},
-    bufloaded={args=1},
+    bufloaded={args=1, base=1},
-    bufname={args={0, 1}},
+    bufname={args={0, 1}, base=1},
-    bufnr={args={0, 2}},
+    bufnr={args={0, 2}, base=1},
-    bufwinid={args=1},
+    bufwinid={args=1, base=1},
-    bufwinnr={args=1},
+    bufwinnr={args=1, base=1},
-    byte2line={args=1},
+    byte2line={args=1, base=1},
-    byteidx={args=2},
+    byteidx={args=2, base=1},
-    byteidxcomp={args=2},
+    byteidxcomp={args=2, base=1},
-    call={args={2, 3}},
+    call={args={2, 3}, base=1},
-    ceil={args=1, func="float_op_wrapper", data="&ceil"},
+    ceil={args=1, base=1, func="float_op_wrapper", data="&ceil"},
     changenr={},
     chanclose={args={1, 2}},
     chansend={args=2},
-    char2nr={args={1, 2}},
+    char2nr={args={1, 2}, base=1},
     charidx={args={2, 3}},
-    cindent={args=1},
+    cindent={args=1, base=1},
-    clearmatches={args={0, 1}},
+    clearmatches={args={0, 1}, base=1},
-    col={args=1},
+    col={args=1, base=1},
-    complete={args=2},
+    complete={args=2, base=2},
-    complete_add={args=1},
+    complete_add={args=1, base=1},
     complete_check={},
-    complete_info={args={0, 1}},
+    complete_info={args={0, 1}, base=1},
-    confirm={args={1, 4}},
+    confirm={args={1, 4}, base=1},
-    copy={args=1},
+    copy={args=1, base=1},
-    cos={args=1, func="float_op_wrapper", data="&cos"},
+    cos={args=1, base=1, func="float_op_wrapper", data="&cos"},
-    cosh={args=1, func="float_op_wrapper", data="&cosh"},
+    cosh={args=1, base=1, func="float_op_wrapper", data="&cosh"},
-    count={args={2, 4}},
+    count={args={2, 4}, base=1},
     cscope_connection={args={0, 3}},
     ctxget={args={0, 1}},
     ctxpop={},
     ctxpush={args={0, 1}},
     ctxset={args={1, 2}},
     ctxsize={},
-    cursor={args={1, 3}},
+    cursor={args={1, 3}, base=1},
-    debugbreak={args={1, 1}},
+    debugbreak={args={1, 1}, base=1},
-    deepcopy={args={1, 2}},
+    deepcopy={args={1, 2}, base=1},
-    delete={args={1,2}},
+    delete={args={1,2}, base=1},
-    deletebufline={args={2,3}},
+    deletebufline={args={2,3}, base=1},
     dictwatcheradd={args=3},
     dictwatcherdel={args=3},
     did_filetype={},
-    diff_filler={args=1},
+    diff_filler={args=1, base=1},
-    diff_hlID={args=2},
+    diff_hlID={args=2, base=1},
-    empty={args=1},
+    empty={args=1, base=1},
     environ={},
     escape={args=2},
-    eval={args=1},
+    eval={args=1, base=1},
     eventhandler={},
     executable={args=1},
     execute={args={1, 2}},
     exepath={args=1},
     exists={args=1},
-    exp={args=1, func="float_op_wrapper", data="&exp"},
+    exp={args=1, base=1, func="float_op_wrapper", data="&exp"},
     expand={args={1, 3}},
     expandcmd={args=1},
-    extend={args={2, 3}},
+    extend={args={2, 3}, base=1},
     feedkeys={args={1, 2}},
     file_readable={args=1, func='f_filereadable'},  -- obsolete
     filereadable={args=1},
     filewritable={args=1},
-    filter={args=2},
+    filter={args=2, base=1},
     finddir={args={1, 3}},
     findfile={args={1, 3}},
     flatten={args={1, 2}},
-    float2nr={args=1},
+    float2nr={args=1, base=1},
-    floor={args=1, func="float_op_wrapper", data="&floor"},
+    floor={args=1, base=1, func="float_op_wrapper", data="&floor"},
-    fmod={args=2},
+    fmod={args=2, base=1},
     fnameescape={args=1},
     fnamemodify={args=2},
     foldclosed={args=1},
@@ -128,7 +135,7 @@ return {
     funcref={args={1, 3}},
     ['function']={args={1, 3}},
     garbagecollect={args={0, 1}},
-    get={args={2, 3}},
+    get={args={2, 3}, base=1},
     getbufinfo={args={0, 1}},
     getbufline={args={2, 3}},
     getbufvar={args={2, 3}},
@@ -173,7 +180,7 @@ return {
     glob2regpat={args=1},
     globpath={args={2, 5}},
     has={args=1},
-    has_key={args=2},
+    has_key={args=2, base=1},
     haslocaldir={args={0,2}},
     hasmapto={args={1, 3}},
     highlightID={args=1, func='f_hlID'},  -- obsolete
@@ -187,22 +194,22 @@ return {
     hostname={},
     iconv={args=3},
     indent={args=1},
-    index={args={2, 4}},
+    index={args={2, 4}, base=1},
     input={args={1, 3}},
     inputdialog={args={1, 3}},
     inputlist={args=1},
     inputrestore={},
     inputsave={},
     inputsecret={args={1, 2}},
-    insert={args={2, 3}},
+    insert={args={2, 3}, base=1},
     interrupt={args=0},
-    invert={args=1},
+    invert={args=1, base=1},
     isdirectory={args=1},
-    isinf={args=1},
+    isinf={args=1, base=1},
     islocked={args=1},
-    isnan={args=1},
+    isnan={args=1, base=1},
     id={args=1},
-    items={args=1},
+    items={args=1, base=1},
     jobclose={args={1, 2}, func="f_chanclose"},
     jobpid={args=1},
     jobresize={args=3},
@@ -210,12 +217,12 @@ return {
     jobstart={args={1, 2}},
     jobstop={args=1},
     jobwait={args={1, 2}},
-    join={args={1, 2}},
+    join={args={1, 2}, base=1},
     json_decode={args=1},
     json_encode={args=1},
-    keys={args=1},
+    keys={args=1, base=1},
     last_buffer_nr={},  -- obsolete
-    len={args=1},
+    len={args=1, base=1},
     libcall={args=3},
     libcallnr={args=3},
     line={args={1, 2}},
@@ -223,10 +230,10 @@ return {
     lispindent={args=1},
     list2str={args={1, 2}},
     localtime={},
-    log={args=1, func="float_op_wrapper", data="&log"},
+    log={args=1, base=1, func="float_op_wrapper", data="&log"},
-    log10={args=1, func="float_op_wrapper", data="&log10"},
+    log10={args=1, base=1, func="float_op_wrapper", data="&log10"},
     luaeval={args={1, 2}},
-    map={args=2},
+    map={args=2, base=1},
     maparg={args={1, 4}},
     mapcheck={args={1, 3}},
     match={args={2, 4}},
@@ -238,20 +245,20 @@ return {
     matchlist={args={2, 4}},
     matchstr={args={2, 4}},
     matchstrpos={args={2,4}},
-    max={args=1},
+    max={args=1, base=1},
     menu_get={args={1, 2}},
-    min={args=1},
+    min={args=1, base=1},
     mkdir={args={1, 3}},
     mode={args={0, 1}},
     msgpackdump={args=1},
     msgpackparse={args=1},
     nextnonblank={args=1},
     nr2char={args={1, 2}},
-    ['or']={args=2},
+    ['or']={args=2, base=1},
     pathshorten={args=1},
-    pow={args=2},
+    pow={args=2, base=1},
     prevnonblank={args=1},
-    printf={args=varargs(1)},
+    printf={args=varargs(1), base=2},
     prompt_getprompt={args=1},
     prompt_setcallback={args={2, 2}},
     prompt_setinterrupt={args={2, 2}},
@@ -270,12 +277,12 @@ return {
     reltime={args={0, 2}},
     reltimefloat={args=1},
     reltimestr={args=1},
-    remove={args={2, 3}},
+    remove={args={2, 3}, base=1},
     rename={args=2},
-    ['repeat']={args=2},
+    ['repeat']={args=2, base=1},
     resolve={args=1},
-    reverse={args=1},
+    reverse={args=1, base=1},
-    round={args=1, func="float_op_wrapper", data="&round"},
+    round={args=1, base=1, func="float_op_wrapper", data="&round"},
     rpcnotify={args=varargs(2)},
     rpcrequest={args=varargs(2)},
     rpcstart={args={1, 2}},
@@ -324,19 +331,19 @@ return {
     sign_unplace={args={1, 2}},
     sign_unplacelist={args={1}},
     simplify={args=1},
-    sin={args=1, func="float_op_wrapper", data="&sin"},
+    sin={args=1, base=1, func="float_op_wrapper", data="&sin"},
-    sinh={args=1, func="float_op_wrapper", data="&sinh"},
+    sinh={args=1, base=1, func="float_op_wrapper", data="&sinh"},
     sockconnect={args={2,3}},
-    sort={args={1, 3}},
+    sort={args={1, 3}, base=1},
     soundfold={args=1},
     stdioopen={args=1},
     spellbadword={args={0, 1}},
     spellsuggest={args={1, 3}},
-    split={args={1, 3}},
+    split={args={1, 3}, base=1},
-    sqrt={args=1, func="float_op_wrapper", data="&sqrt"},
+    sqrt={args=1, base=1, func="float_op_wrapper", data="&sqrt"},
     stdpath={args=1},
-    str2float={args=1},
+    str2float={args=1, base=1},
-    str2list={args={1, 2}},
+    str2list={args={1, 2}, base=1},
     str2nr={args={1, 2}},
     strcharpart={args={2, 3}},
     strchars={args={1,2}},
@@ -344,31 +351,31 @@ return {
     strftime={args={1, 2}},
     strgetchar={args={2, 2}},
     stridx={args={2, 3}},
-    string={args=1},
+    string={args=1, base=1},
-    strlen={args=1},
+    strlen={args=1, base=1},
     strpart={args={2, 4}},
     strptime={args=2},
     strridx={args={2, 3}},
-    strtrans={args=1},
+    strtrans={args=1, base=1},
-    strwidth={args=1},
+    strwidth={args=1, base=1},
     submatch={args={1, 2}},
-    substitute={args=4},
+    substitute={args=4, base=1},
     swapinfo={args={1}},
     swapname={args={1}},
     synID={args=3},
-    synIDattr={args={2, 3}},
+    synIDattr={args={2, 3}, base=1},
-    synIDtrans={args=1},
+    synIDtrans={args=1, base=1},
     synconcealed={args=2},
     synstack={args=2},
-    system={args={1, 2}},
+    system={args={1, 2}, base=1},
-    systemlist={args={1, 3}},
+    systemlist={args={1, 3}, base=1},
     tabpagebuflist={args={0, 1}},
     tabpagenr={args={0, 1}},
     tabpagewinnr={args={1, 2}},
     tagfiles={},
     taglist={args={1, 2}},
-    tan={args=1, func="float_op_wrapper", data="&tan"},
+    tan={args=1, base=1, func="float_op_wrapper", data="&tan"},
-    tanh={args=1, func="float_op_wrapper", data="&tanh"},
+    tanh={args=1, base=1, func="float_op_wrapper", data="&tanh"},
     tempname={},
     termopen={args={1, 2}},
     test_garbagecollect_now={},
@@ -382,12 +389,12 @@ return {
     toupper={args=1},
     tr={args=3},
     trim={args={1,3}},
-    trunc={args=1, func="float_op_wrapper", data="&trunc"},
+    trunc={args=1, base=1, func="float_op_wrapper", data="&trunc"},
-    type={args=1},
+    type={args=1, base=1},
     undofile={args=1},
     undotree={},
-    uniq={args={1, 3}},
+    uniq={args={1, 3}, base=1},
-    values={args=1},
+    values={args=1, base=1},
     virtcol={args=1},
     visualmode={args={0, 1}},
     wait={args={2,3}},
@@ -401,7 +408,7 @@ return {
     win_id2win={args=1},
     win_screenpos={args=1},
     win_splitmove={args={2, 3}},
-    winbufnr={args=1},
+    winbufnr={args=1, base=1},
     wincol={},
     windowsversion={},
     winheight={args=1},
@@ -414,6 +421,6 @@ return {
     winwidth={args=1},
     wordcount={},
     writefile={args={2, 3}},
-    xor={args=2},
+    xor={args=2, base=1},
   },
 }

src/nvim/eval/funcs.c

@@ -175,6 +175,53 @@ const VimLFuncDef *find_internal_func(const char *const name)
   return find_internal_func_gperf(name, len);
 }
 
+int call_internal_func(const char_u *const fname, const int argcount,
+                       typval_T *const argvars, typval_T *const rettv)
+  FUNC_ATTR_NONNULL_ALL
+{
+  const VimLFuncDef *const fdef = find_internal_func((const char *)fname);
+  if (fdef == NULL) {
+    return ERROR_UNKNOWN;
+  } else if (argcount < fdef->min_argc) {
+    return ERROR_TOOFEW;
+  } else if (argcount > fdef->max_argc) {
+    return ERROR_TOOMANY;
+  }
+  argvars[argcount].v_type = VAR_UNKNOWN;
+  fdef->func(argvars, rettv, fdef->data);
+  return ERROR_NONE;
+}
+
+/// Invoke a method for base->method().
+int call_internal_method(const char_u *const fname, const int argcount,
+                         typval_T *const argvars, typval_T *const rettv,
+                         typval_T *const basetv)
+  FUNC_ATTR_NONNULL_ALL
+{
+  const VimLFuncDef *const fdef = find_internal_func((const char *)fname);
+  if (fdef == NULL) {
+    return ERROR_UNKNOWN;
+  } else if (fdef->base_arg == BASE_NONE) {
+    return ERROR_NOTMETHOD;
+  } else if (argcount + 1 < fdef->min_argc) {
+    return ERROR_TOOFEW;
+  } else if (argcount + 1 > fdef->max_argc) {
+    return ERROR_TOOMANY;
+  }
+
+  typval_T argv[MAX_FUNC_ARGS + 1];
+  const ptrdiff_t base_index
+      = fdef->base_arg == BASE_LAST ? argcount : fdef->base_arg - 1;
+  memcpy(argv, argvars, base_index * sizeof(typval_T));
+  argv[base_index] = *basetv;
+  memcpy(argv + base_index + 1, argvars + base_index,
+         (argcount - base_index) * sizeof(typval_T));
+  argv[argcount + 1].v_type = VAR_UNKNOWN;
+
+  fdef->func(argv, rettv, fdef->data);
+  return ERROR_NONE;
+}
+
 /*
  * Return TRUE for a non-zero Number and a non-empty String.
  */
@@ -9420,7 +9467,6 @@ static int item_compare2(const void *s1, const void *s2, bool keep_zero)
   int res;
   typval_T rettv;
   typval_T argv[3];
-  int dummy;
   const char *func_name;
   partial_T *partial = sortinfo->item_compare_partial;
 
@@ -9444,10 +9490,11 @@ static int item_compare2(const void *s1, const void *s2, bool keep_zero)
   tv_copy(TV_LIST_ITEM_TV(si2->item), &argv[1]);
 
   rettv.v_type = VAR_UNKNOWN;  // tv_clear() uses this
-  res = call_func((const char_u *)func_name,
+  funcexe_T funcexe = FUNCEXE_INIT;
-                  -1,
+  funcexe.evaluate = true;
-                  &rettv, 2, argv, NULL, 0L, 0L, &dummy, true,
+  funcexe.partial = partial;
-                  partial, sortinfo->item_compare_selfdict);
+  funcexe.selfdict = sortinfo->item_compare_selfdict;
+  res = call_func((const char_u *)func_name, -1, &rettv, 2, argv, &funcexe);
   tv_clear(&argv[0]);
   tv_clear(&argv[1]);
 

src/nvim/eval/funcs.h

@@ -9,11 +9,16 @@ typedef void (*FunPtr)(void);
 /// Prototype of C function that implements VimL function
 typedef void (*VimLFunc)(typval_T *args, typval_T *rvar, FunPtr data);
 
+/// Special flags for base_arg @see VimLFuncDef
+#define BASE_NONE 0          ///< Not a method (no base argument).
+#define BASE_LAST UINT8_MAX  ///< Use the last argument as the method base.
+
 /// Structure holding VimL function definition
 typedef struct fst {
   char *name;        ///< Name of the function.
   uint8_t min_argc;  ///< Minimal number of arguments.
   uint8_t max_argc;  ///< Maximal number of arguments.
+  uint8_t base_arg;  ///< Method base arg # (1-indexed), BASE_NONE or BASE_LAST.
   VimLFunc func;     ///< Function implementation.
   FunPtr data;       ///< Userdata for function implementation.
 } VimLFuncDef;

src/nvim/eval/userfunc.c

@@ -414,12 +414,7 @@ get_func_tv(
     int len,                // length of "name" or -1 to use strlen()
     typval_T *rettv,
     char_u **arg,           // argument, pointing to the '('
-    linenr_T firstline,     // first line of range
+    funcexe_T *funcexe      // various values
-    linenr_T lastline,      // last line of range
-    int *doesrange,         // return: function handled range
-    int evaluate,
-    partial_T *partial,     // for extra arguments
-    dict_T *selfdict        // Dictionary for "self"
 )
 {
   char_u      *argp;
@@ -431,12 +426,13 @@ get_func_tv(
    * Get the arguments.
    */
   argp = *arg;
-  while (argcount < MAX_FUNC_ARGS - (partial == NULL ? 0 : partial->pt_argc)) {
+  while (argcount < MAX_FUNC_ARGS
+         - (funcexe->partial == NULL ? 0 : funcexe->partial->pt_argc)) {
     argp = skipwhite(argp + 1);             // skip the '(' or ','
     if (*argp == ')' || *argp == ',' || *argp == NUL) {
       break;
     }
-    if (eval1(&argp, &argvars[argcount], evaluate) == FAIL) {
+    if (eval1(&argp, &argvars[argcount], funcexe->evaluate) == FAIL) {
       ret = FAIL;
       break;
     }
@@ -463,9 +459,7 @@ get_func_tv(
         ((typval_T **)funcargs.ga_data)[funcargs.ga_len++] = &argvars[i];
       }
     }
-    ret = call_func(name, len, rettv, argcount, argvars, NULL,
+    ret = call_func(name, len, rettv, argcount, argvars, funcexe);
-                    firstline, lastline, doesrange, evaluate,
-                    partial, selfdict);
 
     funcargs.ga_len -= i;
   } else if (!aborting()) {
@@ -1367,7 +1361,6 @@ int func_call(char_u *name, typval_T *args, partial_T *partial,
 {
   typval_T argv[MAX_FUNC_ARGS + 1];
   int argc = 0;
-  int dummy;
   int r = 0;
 
   TV_LIST_ITER(args->vval.v_list, item, {
@@ -1380,9 +1373,13 @@ int func_call(char_u *name, typval_T *args, partial_T *partial,
     tv_copy(TV_LIST_ITEM_TV(item), &argv[argc++]);
   });
 
-  r = call_func(name, -1, rettv, argc, argv, NULL,
+  funcexe_T funcexe = FUNCEXE_INIT;
-                curwin->w_cursor.lnum, curwin->w_cursor.lnum,
+  funcexe.firstline = curwin->w_cursor.lnum;
-                &dummy, true, partial, selfdict);
+  funcexe.lastline = curwin->w_cursor.lnum;
+  funcexe.evaluate = true;
+  funcexe.partial = partial;
+  funcexe.selfdict = selfdict;
+  r = call_func(name, -1, rettv, argc, argv, &funcexe);
 
 func_call_skip_call:
   // Free the arguments.
@@ -1402,6 +1399,9 @@ static void user_func_error(int error, const char_u *name)
     case ERROR_UNKNOWN:
       emsg_funcname(N_("E117: Unknown function: %s"), name);
       break;
+    case ERROR_NOTMETHOD:
+      emsg_funcname(N_("E276: Cannot use function as a method: %s"), name);
+      break;
     case ERROR_DELETED:
       emsg_funcname(N_("E933: Function was deleted: %s"), name);
       break;
@@ -1423,12 +1423,25 @@ static void user_func_error(int error, const char_u *name)
   }
 }
 
+/// Used by call_func to add a method base (if any) to a function argument list
+/// as the first argument. @see call_func
+static void argv_add_base(typval_T *const basetv, typval_T **const argvars,
+                          int *const argcount, typval_T *const new_argvars,
+                          int *const argv_base)
+  FUNC_ATTR_NONNULL_ARG(2, 3, 4, 5)
+{
+  if (basetv != NULL) {
+    // Method call: base->Method()
+    memmove(&new_argvars[1], *argvars, sizeof(typval_T) * (*argcount));
+    new_argvars[0] = *basetv;
+    (*argcount)++;
+    *argvars = new_argvars;
+    *argv_base = 1;
+  }
+}
+
 /// Call a function with its resolved parameters
 ///
-/// "argv_func", when not NULL, can be used to fill in arguments only when the
-/// invoked function uses them. It is called like this:
-///   new_argcount = argv_func(current_argcount, argv, called_func_argcount)
-///
 /// @return FAIL if function cannot be called, else OK (even if an error
 ///         occurred while executing the function! Set `msg_list` to capture
 ///         the error, see do_cmdline()).
@@ -1440,15 +1453,9 @@ call_func(
     int argcount_in,                // number of "argvars"
     typval_T *argvars_in,           // vars for arguments, must have "argcount"
                                     // PLUS ONE elements!
-    ArgvFunc argv_func,             // function to fill in argvars
+    funcexe_T *funcexe              // more arguments
-    linenr_T firstline,             // first line of range
-    linenr_T lastline,              // last line of range
-    int *doesrange,                 // [out] function handled range
-    bool evaluate,
-    partial_T *partial,             // optional, can be NULL
-    dict_T *selfdict_in             // Dictionary for "self"
 )
-  FUNC_ATTR_NONNULL_ARG(1, 3, 5, 9)
+  FUNC_ATTR_NONNULL_ARG(1, 3, 5, 6)
 {
   int ret = FAIL;
   int error = ERROR_NONE;
@@ -1459,9 +1466,12 @@ call_func(
   char_u *name = NULL;
   int argcount = argcount_in;
   typval_T *argvars = argvars_in;
-  dict_T *selfdict = selfdict_in;
+  dict_T *selfdict = funcexe->selfdict;
-  typval_T argv[MAX_FUNC_ARGS + 1];  // used when "partial" is not NULL
+  typval_T argv[MAX_FUNC_ARGS + 1];  // used when "partial" or
+                                     // "funcexe->basetv" is not NULL
   int argv_clear = 0;
+  int argv_base = 0;
+  partial_T *partial = funcexe->partial;
 
   // Initialize rettv so that it is safe for caller to invoke clear_tv(rettv)
   // even when call_func() returns FAIL.
@@ -1480,14 +1490,15 @@ call_func(
     fname = fname_trans_sid(name, fname_buf, &tofree, &error);
   }
 
-  *doesrange = false;
+  if (funcexe->doesrange != NULL) {
+    *funcexe->doesrange = false;
+  }
 
   if (partial != NULL) {
     // When the function has a partial with a dict and there is a dict
     // argument, use the dict argument. That is backwards compatible.
     // When the dict was bound explicitly use the one from the partial.
-    if (partial->pt_dict != NULL
+    if (partial->pt_dict != NULL && (selfdict == NULL || !partial->pt_auto)) {
-        && (selfdict_in == NULL || !partial->pt_auto)) {
       selfdict = partial->pt_dict;
     }
     if (error == ERROR_NONE && partial->pt_argc > 0) {
@@ -1506,7 +1517,7 @@ call_func(
     }
   }
 
-  if (error == ERROR_NONE && evaluate) {
+  if (error == ERROR_NONE && funcexe->evaluate) {
     char_u *rfname = fname;
 
     // Ignore "g:" before a function name.
@@ -1521,7 +1532,12 @@ call_func(
     if (is_luafunc(partial)) {
       if (len > 0) {
         error = ERROR_NONE;
+        argv_add_base(funcexe->basetv, &argvars, &argcount, argv, &argv_base);
         nlua_typval_call((const char *)funcname, len, argvars, argcount, rettv);
+      } else {
+        // v:lua was called directly; show its name in the emsg
+        XFREE_CLEAR(name);
+        funcname = (const char_u *)"v:lua";
       }
     } else if (fp != NULL || !builtin_function((const char *)rfname, -1)) {
       // User defined function.
@@ -1549,13 +1565,16 @@ call_func(
         cfunc_T cb = fp->uf_cb;
         error = (*cb)(argcount, argvars, rettv, fp->uf_cb_state);
       } else if (fp != NULL) {
-        if (argv_func != NULL) {
+        if (funcexe->argv_func != NULL) {
           // postponed filling in the arguments, do it now
-          argcount = argv_func(argcount, argvars, argv_clear,
+          argcount = funcexe->argv_func(argcount, argvars, argv_clear,
                                         fp->uf_args.ga_len);
         }
-        if (fp->uf_flags & FC_RANGE) {
+
-          *doesrange = true;
+        argv_add_base(funcexe->basetv, &argvars, &argcount, argv, &argv_base);
+
+        if (fp->uf_flags & FC_RANGE && funcexe->doesrange != NULL) {
+          *funcexe->doesrange = true;
         }
         if (argcount < fp->uf_args.ga_len - fp->uf_def_args.ga_len) {
           error = ERROR_TOOFEW;
@@ -1565,25 +1584,20 @@ call_func(
           error = ERROR_DICT;
         } else {
           // Call the user function.
-          call_user_func(fp, argcount, argvars, rettv, firstline, lastline,
+          call_user_func(fp, argcount, argvars, rettv, funcexe->firstline,
+                         funcexe->lastline,
                          (fp->uf_flags & FC_DICT) ? selfdict : NULL);
           error = ERROR_NONE;
         }
       }
+    } else if (funcexe->basetv != NULL) {
+      // expr->method(): Find the method name in the table, call its
+      // implementation with the base as one of the arguments.
+      error = call_internal_method(fname, argcount, argvars, rettv,
+                                   funcexe->basetv);
     } else {
       // Find the function name in the table, call its implementation.
-      const VimLFuncDef *const fdef = find_internal_func((const char *)fname);
+      error = call_internal_func(fname, argcount, argvars, rettv);
-      if (fdef != NULL) {
-        if (argcount < fdef->min_argc) {
-          error = ERROR_TOOFEW;
-        } else if (argcount > fdef->max_argc) {
-          error = ERROR_TOOMANY;
-        } else {
-          argvars[argcount].v_type = VAR_UNKNOWN;
-          fdef->func(argvars, rettv, fdef->data);
-          error = ERROR_NONE;
-        }
-      }
     }
     /*
      * The function call (or "FuncUndefined" autocommand sequence) might
@@ -1607,9 +1621,11 @@ theend:
     user_func_error(error, (name != NULL) ? name : funcname);
   }
 
+  // clear the copies made from the partial
   while (argv_clear > 0) {
-    tv_clear(&argv[--argv_clear]);
+    tv_clear(&argv[--argv_clear + argv_base]);
   }
+
   xfree(tofree);
   xfree(name);
 
@@ -2901,7 +2917,7 @@ void ex_call(exarg_T *eap)
   int len;
   typval_T rettv;
   linenr_T lnum;
-  int doesrange;
+  bool doesrange;
   bool failed = false;
   funcdict_T fudi;
   partial_T *partial = NULL;
@@ -2947,7 +2963,7 @@ void ex_call(exarg_T *eap)
   rettv.v_type = VAR_UNKNOWN;  // tv_clear() uses this.
 
   if (*startarg != '(') {
-    EMSG2(_("E107: Missing parentheses: %s"), eap->arg);
+    EMSG2(_(e_missingparen), eap->arg);
     goto end;
   }
 
@@ -2965,15 +2981,22 @@ void ex_call(exarg_T *eap)
       curwin->w_cursor.coladd = 0;
     }
     arg = startarg;
-    if (get_func_tv(name, -1, &rettv, &arg,
+
-                    eap->line1, eap->line2, &doesrange,
+    funcexe_T funcexe = FUNCEXE_INIT;
-                    true, partial, fudi.fd_dict) == FAIL) {
+    funcexe.firstline = eap->line1;
+    funcexe.lastline = eap->line2;
+    funcexe.doesrange = &doesrange;
+    funcexe.evaluate = true;
+    funcexe.partial = partial;
+    funcexe.selfdict = fudi.fd_dict;
+    if (get_func_tv(name, -1, &rettv, &arg, &funcexe) == FAIL) {
       failed = true;
       break;
     }
 
     // Handle a function returning a Funcref, Dictionary or List.
-    if (handle_subscript((const char **)&arg, &rettv, true, true)
+    if (handle_subscript((const char **)&arg, &rettv, true, true,
+                         (const char_u *)name, (const char_u **)&name)
         == FAIL) {
       failed = true;
       break;

src/nvim/eval/userfunc.h

@@ -28,11 +28,37 @@ typedef enum {
   ERROR_OTHER,
   ERROR_BOTH,
   ERROR_DELETED,
+  ERROR_NOTMETHOD,
 } FnameTransError;
 
+/// Used in funcexe_T. Returns the new argcount.
 typedef int (*ArgvFunc)(int current_argcount, typval_T *argv, int argskip,
                         int called_func_argcount);
 
+/// Structure passed between functions dealing with function call execution.
+typedef struct {
+  ArgvFunc argv_func;  ///< when not NULL, can be used to fill in arguments only
+                       ///< when the invoked function uses them
+  linenr_T firstline;  ///< first line of range
+  linenr_T lastline;   ///< last line of range
+  bool *doesrange;     ///< [out] if not NULL: function handled range
+  bool evaluate;       ///< actually evaluate expressions
+  partial_T *partial;  ///< for extra arguments
+  dict_T *selfdict;    ///< Dictionary for "self"
+  typval_T *basetv;    ///< base for base->method()
+} funcexe_T;
+
+#define FUNCEXE_INIT (funcexe_T) { \
+  .argv_func = NULL, \
+  .firstline = 0, \
+  .lastline = 0, \
+  .doesrange = NULL, \
+  .evaluate = false, \
+  .partial = NULL, \
+  .selfdict = NULL, \
+  .basetv = NULL, \
+}
+
 #define FUNCARG(fp, j)  ((char_u **)(fp->uf_args.ga_data))[j]
 #define FUNCLINE(fp, j) ((char_u **)(fp->uf_lines.ga_data))[j]
 

src/nvim/generators/gen_eval.lua

@@ -42,7 +42,7 @@ gperfpipe:write([[
 %language=ANSI-C
 %global-table
 %readonly-tables
-%define initializer-suffix ,0,0,NULL,NULL
+%define initializer-suffix ,0,0,BASE_NONE,NULL,NULL
 %define word-array-name functions
 %define hash-function-name hash_internal_func_gperf
 %define lookup-function-name find_internal_func_gperf
@@ -59,9 +59,10 @@ for name, def in pairs(funcs) do
   elseif #args == 1 then
     args[2] = 'MAX_FUNC_ARGS'
   end
+  local base = def.base or "BASE_NONE"
   local func = def.func or ('f_' .. name)
   local data = def.data or "NULL"
-  gperfpipe:write(('%s,  %s, %s, &%s, (FunPtr)%s\n')
+  gperfpipe:write(('%s,  %s, %s, %s, &%s, (FunPtr)%s\n')
-                  :format(name, args[1], args[2], func, data))
+                  :format(name, args[1], args[2], base, func, data))
 end
 gperfpipe:close()

src/nvim/globals.h

@@ -972,6 +972,7 @@ EXTERN char_u e_write[] INIT(= N_("E80: Error while writing"));
 EXTERN char_u e_zerocount[] INIT(= N_("E939: Positive count required"));
 EXTERN char_u e_usingsid[] INIT(= N_(
     "E81: Using <SID> not in a script context"));
+EXTERN char_u e_missingparen[] INIT(= N_("E107: Missing parentheses: %s"));
 EXTERN char_u e_maxmempat[] INIT(= N_(
         "E363: pattern uses more memory than 'maxmempattern'"));
 EXTERN char_u e_emptybuf[] INIT(= N_("E749: empty buffer"));

src/nvim/lua/executor.c

@@ -785,13 +785,13 @@ int nlua_call(lua_State *lstate)
 
     try_start();
     typval_T rettv;
-    int dummy;
+    funcexe_T funcexe = FUNCEXE_INIT;
+    funcexe.firstline = curwin->w_cursor.lnum;
+    funcexe.lastline = curwin->w_cursor.lnum;
+    funcexe.evaluate = true;
     // call_func() retval is deceptive, ignore it.  Instead we set `msg_list`
     // (TRY_WRAP) to capture abort-causing non-exception errors.
-    (void)call_func(name, (int)name_len, &rettv, nargs,
+    (void)call_func(name, (int)name_len, &rettv, nargs, vim_args, &funcexe);
-                    vim_args, NULL,
-                    curwin->w_cursor.lnum, curwin->w_cursor.lnum,
-                    &dummy, true, NULL, NULL);
     if (!try_end(&err)) {
       nlua_push_typval(lstate, &rettv, false);
     }

src/nvim/normal.c

@@ -2531,12 +2531,12 @@ do_mouse (
             }
           };
           typval_T rettv;
-          int doesrange;
+          funcexe_T funcexe = FUNCEXE_INIT;
-          (void)call_func((char_u *)tab_page_click_defs[mouse_col].func,
+          funcexe.firstline = curwin->w_cursor.lnum;
-                          -1,
+          funcexe.lastline = curwin->w_cursor.lnum;
-                          &rettv, ARRAY_SIZE(argv), argv, NULL,
+          funcexe.evaluate = true;
-                          curwin->w_cursor.lnum, curwin->w_cursor.lnum,
+          (void)call_func((char_u *)tab_page_click_defs[mouse_col].func, -1,
-                          &doesrange, true, NULL, NULL);
+                          &rettv, ARRAY_SIZE(argv), argv, &funcexe);
           tv_clear(&rettv);
           break;
         }

src/nvim/regexp.c

@@ -6726,26 +6726,24 @@ static int vim_regsub_both(char_u *source, typval_T *expr, char_u *dest,
 
       if (expr != NULL) {
         typval_T argv[2];
-        int dummy;
         typval_T rettv;
         staticList10_T matchList = TV_LIST_STATIC10_INIT;
-
         rettv.v_type = VAR_STRING;
         rettv.vval.v_string = NULL;
         argv[0].v_type = VAR_LIST;
         argv[0].vval.v_list = &matchList.sl_list;
+        funcexe_T funcexe = FUNCEXE_INIT;
+        funcexe.argv_func = fill_submatch_list;
+        funcexe.evaluate = true;
         if (expr->v_type == VAR_FUNC) {
           s = expr->vval.v_string;
-          call_func(s, -1, &rettv, 1, argv,
+          call_func(s, -1, &rettv, 1, argv, &funcexe);
-                    fill_submatch_list, 0L, 0L, &dummy,
-                    true, NULL, NULL);
         } else if (expr->v_type == VAR_PARTIAL) {
           partial_T *partial = expr->vval.v_partial;
 
           s = partial_name(partial);
-          call_func(s, -1, &rettv, 1, argv,
+          funcexe.partial = partial;
-                    fill_submatch_list, 0L, 0L, &dummy,
+          call_func(s, -1, &rettv, 1, argv, &funcexe);
-                    true, partial, NULL);
         }
         if (tv_list_len(&matchList.sl_list) > 0) {
           // fill_submatch_list() was called.

src/nvim/testdir/sautest/autoload/foo.vim

@@ -5,3 +5,7 @@ let foo#bar = {}
 func foo#bar.echo()
   let g:called_foo_bar_echo += 1
 endfunc
+
+func foo#addFoo(head)
+  return a:head .. 'foo'
+endfunc

src/nvim/testdir/test_arglist.vim

@@ -90,8 +90,8 @@ func Test_argadd_empty_curbuf()
   call assert_equal('', bufname('%'))
   call assert_equal(1, line('$'))
   rew
-  call assert_notequal(curbuf, bufnr('%'))
+  call assert_notequal(curbuf, '%'->bufnr())
-  call assert_equal('Xargadd', bufname('%'))
+  call assert_equal('Xargadd', '%'->bufname())
   call assert_equal(2, line('$'))
 
   %argd

src/nvim/testdir/test_assert.vim

@@ -7,7 +7,7 @@ func Test_assert_equalfile()
 
   let goodtext = ["one", "two", "three"]
   call writefile(goodtext, 'Xone')
-  call assert_equal(1, assert_equalfile('Xone', 'xyzxyz'))
+  call assert_equal(1, 'Xone'->assert_equalfile('xyzxyz'))
   call assert_match("E485: Can't read file xyzxyz", v:errors[0])
   call remove(v:errors, 0)
 

src/nvim/testdir/test_autoload.vim

@@ -8,6 +8,8 @@ func Test_autoload_dict_func()
   call g:foo#bar.echo()
   call assert_equal(1, g:loaded_foo_vim)
   call assert_equal(1, g:called_foo_bar_echo)
+
+  eval 'bar'->g:foo#addFoo()->assert_equal('barfoo')
 endfunc
 
 func Test_source_autoload()

src/nvim/testdir/test_bufline.vim

@@ -102,7 +102,7 @@ func Test_deletebufline()
   call assert_equal(0, deletebufline(b, 2, 8))
   call assert_equal(['aaa'], getbufline(b, 1, 2))
   exe "bd!" b
-  call assert_equal(1, deletebufline(b, 1))
+  call assert_equal(1, b->deletebufline(1))
 
   split Xtest
   call setline(1, ['a', 'b', 'c'])
@@ -131,11 +131,11 @@ func Test_appendbufline_redraw()
   endif
   let lines =<< trim END
     new foo
-    let winnr=bufwinnr('foo')
+    let winnr = 'foo'->bufwinnr()
     let buf = bufnr('foo')
     wincmd p
     call appendbufline(buf, '$', range(1,200))
-    exe winnr. 'wincmd w'
+    exe winnr .. 'wincmd w'
     norm! G
     wincmd p
     call deletebufline(buf, 1, '$')

src/nvim/testdir/test_bufwintabinfo.vim

@@ -18,7 +18,7 @@ function Test_getbufwintabinfo()
     let l = getbufinfo('%')
     call assert_equal(bufnr('%'), l[0].bufnr)
     call assert_equal('vim', l[0].variables.editor)
-    call assert_notequal(-1, index(l[0].windows, bufwinid('%')))
+    call assert_notequal(-1, index(l[0].windows, '%'->bufwinid()))
 
     " Test for getbufinfo() with 'bufmodified'
     call assert_equal(0, len(getbufinfo({'bufmodified' : 1})))

src/nvim/testdir/test_cindent.vim

@@ -118,6 +118,16 @@ b = something();
   bw!
 endfunc
 
+func Test_cindent_func()
+  new
+  setlocal cindent
+  call setline(1, ['int main(void)', '{', 'return 0;', '}'])
+  call assert_equal(-1, cindent(0))
+  call assert_equal(&sw, 3->cindent())
+  call assert_equal(-1, cindent(line('$')+1))
+  bwipe!
+endfunc
+
 " this was going beyond the end of the line.
 func Test_cindent_case()
   new

src/nvim/testdir/test_diffmode.vim

@@ -725,7 +725,7 @@ func Test_diff_filler()
   diffthis
   redraw
 
-  call assert_equal([0, 0, 0, 0, 0, 0, 0, 1, 0], map(range(-1, 7), 'diff_filler(v:val)'))
+  call assert_equal([0, 0, 0, 0, 0, 0, 0, 1, 0], map(range(-1, 7), 'v:val->diff_filler()'))
   wincmd w
   call assert_equal([0, 0, 0, 0, 2, 0, 0, 0], map(range(-1, 6), 'diff_filler(v:val)'))
 
@@ -741,16 +741,16 @@ func Test_diff_hlID()
   diffthis
   redraw
 
-  call assert_equal(synIDattr(diff_hlID(-1, 1), "name"), "")
+  call diff_hlID(-1, 1)->synIDattr("name")->assert_equal("")
 
   call assert_equal(diff_hlID(1, 1), hlID("DiffChange"))
-  call assert_equal(synIDattr(diff_hlID(1, 1), "name"), "DiffChange")
+  call diff_hlID(1, 1)->synIDattr("name")->assert_equal("DiffChange")
   call assert_equal(diff_hlID(1, 2), hlID("DiffText"))
-  call assert_equal(synIDattr(diff_hlID(1, 2), "name"), "DiffText")
+  call diff_hlID(1, 2)->synIDattr("name")->assert_equal("DiffText")
-  call assert_equal(synIDattr(diff_hlID(2, 1), "name"), "")
+  call diff_hlID(2, 1)->synIDattr("name")->assert_equal("")
   call assert_equal(diff_hlID(3, 1), hlID("DiffAdd"))
-  call assert_equal(synIDattr(diff_hlID(3, 1), "name"), "DiffAdd")
+  call diff_hlID(3, 1)->synIDattr("name")->assert_equal("DiffAdd")
-  call assert_equal(synIDattr(diff_hlID(4, 1), "name"), "")
+  call diff_hlID(4, 1)->synIDattr("name")->assert_equal("")
 
   wincmd w
   call assert_equal(diff_hlID(1, 1), hlID("DiffChange"))

src/nvim/testdir/test_float_func.vim

@@ -7,6 +7,8 @@ end
 func Test_abs()
   call assert_equal('1.23', string(abs(1.23)))
   call assert_equal('1.23', string(abs(-1.23)))
+  eval -1.23->abs()->string()->assert_equal('1.23')
+
   call assert_equal('0.0', string(abs(0.0)))
   call assert_equal('0.0', string(abs(1.0/(1.0/0.0))))
   call assert_equal('0.0', string(abs(-1.0/(1.0/0.0))))
@@ -22,6 +24,7 @@ endfunc
 func Test_sqrt()
   call assert_equal('0.0', string(sqrt(0.0)))
   call assert_equal('1.414214', string(sqrt(2.0)))
+  eval 2.0->sqrt()->string()->assert_equal('1.414214')
   call assert_equal("str2float('inf')", string(sqrt(1.0/0.0)))
   call assert_equal("str2float('nan')", string(sqrt(-1.0)))
   call assert_equal("str2float('nan')", string(sqrt(0.0/0.0)))
@@ -31,6 +34,7 @@ endfunc
 func Test_log()
   call assert_equal('0.0', string(log(1.0)))
   call assert_equal('-0.693147', string(log(0.5)))
+  eval 0.5->log()->string()->assert_equal('-0.693147')
   call assert_equal("-str2float('inf')", string(log(0.0)))
   call assert_equal("str2float('nan')", string(log(-1.0)))
   call assert_equal("str2float('inf')", string(log(1.0/0.0)))
@@ -42,6 +46,7 @@ func Test_log10()
   call assert_equal('0.0', string(log10(1.0)))
   call assert_equal('2.0', string(log10(100.0)))
   call assert_equal('2.079181', string(log10(120.0)))
+  eval 120.0->log10()->string()->assert_equal('2.079181')
   call assert_equal("-str2float('inf')", string(log10(0.0)))
   call assert_equal("str2float('nan')", string(log10(-1.0)))
   call assert_equal("str2float('inf')", string(log10(1.0/0.0)))
@@ -53,6 +58,7 @@ func Test_exp()
   call assert_equal('1.0', string(exp(0.0)))
   call assert_equal('7.389056', string(exp(2.0)))
   call assert_equal('0.367879', string(exp(-1.0)))
+  eval -1.0->exp()->string()->assert_equal('0.367879')
   call assert_equal("str2float('inf')", string(exp(1.0/0.0)))
   call assert_equal('0.0', string(exp(-1.0/0.0)))
   call assert_equal("str2float('nan')", string(exp(0.0/0.0)))
@@ -63,6 +69,7 @@ func Test_sin()
   call assert_equal('0.0', string(sin(0.0)))
   call assert_equal('0.841471', string(sin(1.0)))
   call assert_equal('-0.479426', string(sin(-0.5)))
+  eval -0.5->sin()->string()->assert_equal('-0.479426')
   call assert_equal("str2float('nan')", string(sin(0.0/0.0)))
   call assert_equal("str2float('nan')", string(sin(1.0/0.0)))
   call assert_equal('0.0', string(sin(1.0/(1.0/0.0))))
@@ -73,6 +80,8 @@ endfunc
 func Test_asin()
   call assert_equal('0.0', string(asin(0.0)))
   call assert_equal('1.570796', string(asin(1.0)))
+  eval 1.0->asin()->string()->assert_equal('1.570796')
+
   call assert_equal('-0.523599', string(asin(-0.5)))
   call assert_equal("str2float('nan')", string(asin(1.1)))
   call assert_equal("str2float('nan')", string(asin(1.0/0.0)))
@@ -84,6 +93,7 @@ func Test_sinh()
   call assert_equal('0.0', string(sinh(0.0)))
   call assert_equal('0.521095', string(sinh(0.5)))
   call assert_equal('-1.026517', string(sinh(-0.9)))
+  eval -0.9->sinh()->string()->assert_equal('-1.026517')
   call assert_equal("str2float('inf')", string(sinh(1.0/0.0)))
   call assert_equal("-str2float('inf')", string(sinh(-1.0/0.0)))
   call assert_equal("str2float('nan')", string(sinh(0.0/0.0)))
@@ -94,6 +104,7 @@ func Test_cos()
   call assert_equal('1.0', string(cos(0.0)))
   call assert_equal('0.540302', string(cos(1.0)))
   call assert_equal('0.877583', string(cos(-0.5)))
+  eval -0.5->cos()->string()->assert_equal('0.877583')
   call assert_equal("str2float('nan')", string(cos(0.0/0.0)))
   call assert_equal("str2float('nan')", string(cos(1.0/0.0)))
   call assert_fails('call cos("")', 'E808:')
@@ -103,6 +114,7 @@ func Test_acos()
   call assert_equal('1.570796', string(acos(0.0)))
   call assert_equal('0.0', string(acos(1.0)))
   call assert_equal('3.141593', string(acos(-1.0)))
+  eval -1.0->acos()->string()->assert_equal('3.141593')
   call assert_equal('2.094395', string(acos(-0.5)))
   call assert_equal("str2float('nan')", string(acos(1.1)))
   call assert_equal("str2float('nan')", string(acos(1.0/0.0)))
@@ -113,6 +125,7 @@ endfunc
 func Test_cosh()
   call assert_equal('1.0', string(cosh(0.0)))
   call assert_equal('1.127626', string(cosh(0.5)))
+  eval 0.5->cosh()->string()->assert_equal('1.127626')
   call assert_equal("str2float('inf')", string(cosh(1.0/0.0)))
   call assert_equal("str2float('inf')", string(cosh(-1.0/0.0)))
   call assert_equal("str2float('nan')", string(cosh(0.0/0.0)))
@@ -123,6 +136,7 @@ func Test_tan()
   call assert_equal('0.0', string(tan(0.0)))
   call assert_equal('0.546302', string(tan(0.5)))
   call assert_equal('-0.546302', string(tan(-0.5)))
+  eval -0.5->tan()->string()->assert_equal('-0.546302')
   call assert_equal("str2float('nan')", string(tan(1.0/0.0)))
   call assert_equal("str2float('nan')", string(cos(0.0/0.0)))
   call assert_equal('0.0', string(tan(1.0/(1.0/0.0))))
@@ -134,6 +148,7 @@ func Test_atan()
   call assert_equal('0.0', string(atan(0.0)))
   call assert_equal('0.463648', string(atan(0.5)))
   call assert_equal('-0.785398', string(atan(-1.0)))
+  eval -1.0->atan()->string()->assert_equal('-0.785398')
   call assert_equal('1.570796', string(atan(1.0/0.0)))
   call assert_equal('-1.570796', string(atan(-1.0/0.0)))
   call assert_equal("str2float('nan')", string(atan(0.0/0.0)))
@@ -144,6 +159,7 @@ func Test_atan2()
   call assert_equal('-2.356194', string(atan2(-1, -1)))
   call assert_equal('2.356194', string(atan2(1, -1)))
   call assert_equal('0.0', string(atan2(1.0, 1.0/0.0)))
+  eval 1.0->atan2(1.0/0.0)->string()->assert_equal('0.0')
   call assert_equal('1.570796', string(atan2(1.0/0.0, 1.0)))
   call assert_equal("str2float('nan')", string(atan2(0.0/0.0, 1.0)))
   call assert_fails('call atan2("", -1)', 'E808:')
@@ -154,6 +170,7 @@ func Test_tanh()
   call assert_equal('0.0', string(tanh(0.0)))
   call assert_equal('0.462117', string(tanh(0.5)))
   call assert_equal('-0.761594', string(tanh(-1.0)))
+  eval -1.0->tanh()->string()->assert_equal('-0.761594')
   call assert_equal('1.0', string(tanh(1.0/0.0)))
   call assert_equal('-1.0', string(tanh(-1.0/0.0)))
   call assert_equal("str2float('nan')", string(tanh(0.0/0.0)))
@@ -164,6 +181,7 @@ func Test_fmod()
   call assert_equal('0.13', string(fmod(12.33, 1.22)))
   call assert_equal('-0.13', string(fmod(-12.33, 1.22)))
   call assert_equal("str2float('nan')", string(fmod(1.0/0.0, 1.0)))
+  eval (1.0/0.0)->fmod(1.0)->string()->assert_equal("str2float('nan')")
   " On Windows we get "nan" instead of 1.0, accept both.
   let res = string(fmod(1.0, 1.0/0.0))
   if res != "str2float('nan')"
@@ -177,6 +195,7 @@ endfunc
 func Test_pow()
   call assert_equal('1.0', string(pow(0.0, 0.0)))
   call assert_equal('8.0', string(pow(2.0, 3.0)))
+  eval 2.0->pow(3.0)->string()->assert_equal('8.0')
   call assert_equal("str2float('nan')", string(pow(2.0, 0.0/0.0)))
   call assert_equal("str2float('nan')", string(pow(0.0/0.0, 3.0)))
   call assert_equal("str2float('nan')", string(pow(0.0/0.0, 3.0)))
@@ -192,6 +211,7 @@ func Test_str2float()
   call assert_equal('1.0', string(str2float(' 1.0 ')))
   call assert_equal('1.23', string(str2float('1.23')))
   call assert_equal('1.23', string(str2float('1.23abc')))
+  eval '1.23abc'->str2float()->string()->assert_equal('1.23')
   call assert_equal('1.0e40', string(str2float('1e40')))
   call assert_equal('-1.23', string(str2float('-1.23')))
   call assert_equal('1.23', string(str2float(' + 1.23 ')))
@@ -228,6 +248,7 @@ func Test_float2nr()
   call assert_equal(1, float2nr(1.234))
   call assert_equal(123, float2nr(1.234e2))
   call assert_equal(12, float2nr(123.4e-1))
+  eval 123.4e-1->float2nr()->assert_equal(12)
   let max_number = 1/0
   let min_number = -max_number
   call assert_equal(max_number/2+1, float2nr(pow(2, 62)))
@@ -242,6 +263,7 @@ func Test_floor()
   call assert_equal('2.0', string(floor(2.0)))
   call assert_equal('2.0', string(floor(2.11)))
   call assert_equal('2.0', string(floor(2.99)))
+  eval 2.99->floor()->string()->assert_equal('2.0')
   call assert_equal('-3.0', string(floor(-2.11)))
   call assert_equal('-3.0', string(floor(-2.99)))
   call assert_equal("str2float('nan')", string(floor(0.0/0.0)))
@@ -255,6 +277,7 @@ func Test_ceil()
   call assert_equal('3.0', string(ceil(2.11)))
   call assert_equal('3.0', string(ceil(2.99)))
   call assert_equal('-2.0', string(ceil(-2.11)))
+  eval -2.11->ceil()->string()->assert_equal('-2.0')
   call assert_equal('-2.0', string(ceil(-2.99)))
   call assert_equal("str2float('nan')", string(ceil(0.0/0.0)))
   call assert_equal("str2float('inf')", string(ceil(1.0/0.0)))
@@ -266,6 +289,7 @@ func Test_round()
   call assert_equal('2.0', string(round(2.1)))
   call assert_equal('3.0', string(round(2.5)))
   call assert_equal('3.0', string(round(2.9)))
+  eval 2.9->round()->string()->assert_equal('3.0')
   call assert_equal('-2.0', string(round(-2.1)))
   call assert_equal('-3.0', string(round(-2.5)))
   call assert_equal('-3.0', string(round(-2.9)))
@@ -279,6 +303,7 @@ func Test_trunc()
   call assert_equal('2.0', string(trunc(2.1)))
   call assert_equal('2.0', string(trunc(2.5)))
   call assert_equal('2.0', string(trunc(2.9)))
+  eval 2.9->trunc()->string()->assert_equal('2.0')
   call assert_equal('-2.0', string(trunc(-2.1)))
   call assert_equal('-2.0', string(trunc(-2.5)))
   call assert_equal('-2.0', string(trunc(-2.9)))
@@ -291,6 +316,7 @@ endfunc
 func Test_isinf()
   call assert_equal(1, isinf(1.0/0.0))
   call assert_equal(-1, isinf(-1.0/0.0))
+  eval (-1.0/0.0)->isinf()->assert_equal(-1)
   call assert_false(isinf(1.0))
   call assert_false(isinf(0.0/0.0))
   call assert_false(isinf('a'))
@@ -302,6 +328,7 @@ func Test_isnan()
   call assert_true(isnan(0.0/0.0))
   call assert_false(isnan(1.0))
   call assert_false(isnan(1.0/0.0))
+  eval (1.0/0.0)->isnan()->assert_false()
   call assert_false(isnan(-1.0/0.0))
   call assert_false(isnan('a'))
   call assert_false(isnan([]))

src/nvim/testdir/test_functions.vim

@@ -852,7 +852,7 @@ func Test_byte2line_line2byte()
 
   set fileformat=mac
   call assert_equal([-1, -1, 1, 1, 2, 2, 2, 3, 3, -1],
-  \                 map(range(-1, 8), 'byte2line(v:val)'))
+  \                 map(range(-1, 8), 'v:val->byte2line()'))
   call assert_equal([-1, -1, 1, 3, 6, 8, -1],
   \                 map(range(-1, 5), 'line2byte(v:val)'))
 
@@ -875,6 +875,34 @@ func Test_byte2line_line2byte()
   bw!
 endfunc
 
+func Test_byteidx()
+  let a = '.é.' " one char of two bytes
+  call assert_equal(0, byteidx(a, 0))
+  call assert_equal(0, byteidxcomp(a, 0))
+  call assert_equal(1, byteidx(a, 1))
+  call assert_equal(1, byteidxcomp(a, 1))
+  call assert_equal(3, byteidx(a, 2))
+  call assert_equal(3, byteidxcomp(a, 2))
+  call assert_equal(4, byteidx(a, 3))
+  call assert_equal(4, byteidxcomp(a, 3))
+  call assert_equal(-1, byteidx(a, 4))
+  call assert_equal(-1, byteidxcomp(a, 4))
+
+  let b = '.é.' " normal e with composing char
+  call assert_equal(0, b->byteidx(0))
+  call assert_equal(1, b->byteidx(1))
+  call assert_equal(4, b->byteidx(2))
+  call assert_equal(5, b->byteidx(3))
+  call assert_equal(-1, b->byteidx(4))
+
+  call assert_equal(0, b->byteidxcomp(0))
+  call assert_equal(1, b->byteidxcomp(1))
+  call assert_equal(2, b->byteidxcomp(2))
+  call assert_equal(4, b->byteidxcomp(3))
+  call assert_equal(5, b->byteidxcomp(4))
+  call assert_equal(-1, b->byteidxcomp(5))
+endfunc
+
 " Test for charidx()
 func Test_charidx()
   let a = 'xáb́y'
@@ -1065,7 +1093,7 @@ func Test_col()
   call assert_equal(7, col('$'))
   call assert_equal(4, col("'x"))
   call assert_equal(6, col("'Y"))
-  call assert_equal(2, col([1, 2]))
+  call assert_equal(2, [1, 2]->col())
   call assert_equal(7, col([1, '$']))
 
   call assert_equal(0, col(''))
@@ -1413,13 +1441,13 @@ func Test_bufadd_bufload()
   call assert_equal([''], getbufline(buf, 1, '$'))
 
   let curbuf = bufnr('')
-  call writefile(['some', 'text'], 'otherName')
+  call writefile(['some', 'text'], 'XotherName')
-  let buf = bufadd('otherName')
+  let buf = 'XotherName'->bufadd()
   call assert_notequal(0, buf)
-  call assert_equal(1, bufexists('otherName'))
+  eval 'XotherName'->bufexists()->assert_equal(1)
   call assert_equal(0, getbufvar(buf, '&buflisted'))
   call assert_equal(0, bufloaded(buf))
-  call bufload(buf)
+  eval buf->bufload()
   call assert_equal(1, bufloaded(buf))
   call assert_equal(['some', 'text'], getbufline(buf, 1, '$'))
   call assert_equal(curbuf, bufnr(''))
@@ -1439,8 +1467,9 @@ func Test_bufadd_bufload()
   call assert_equal(0, bufexists(buf2))
 
   bwipe someName
-  bwipe otherName
+  bwipe XotherName
   call assert_equal(0, bufexists('someName'))
+  call delete('XotherName')
 endfunc
 
 func Test_readdir()
@@ -1473,6 +1502,20 @@ func Test_readdir()
   call delete('Xdir', 'rf')
 endfunc
 
+func Test_call()
+  call assert_equal(3, call('len', [123]))
+  call assert_equal(3, 'len'->call([123]))
+  call assert_fails("call call('len', 123)", 'E714:')
+  call assert_equal(0, call('', []))
+
+  function Mylen() dict
+     return len(self.data)
+  endfunction
+  let mydict = {'data': [0, 1, 2, 3], 'len': function("Mylen")}
+  eval mydict.len->call([], mydict)->assert_equal(4)
+  call assert_fails("call call('Mylen', [], 0)", 'E715:')
+endfunc
+
 " Test for the eval() function
 func Test_eval()
   call assert_fails("call eval('5 a')", 'E488:')

src/nvim/testdir/test_hide.vim

@@ -37,7 +37,7 @@ function Test_hide()
   " :hide as a command
   hide
   call assert_equal([orig_bname, orig_winnr], [bufname(''), winnr('$')])
-  call assert_equal([1, 1], [buflisted('Xf1'), bufloaded('Xf1')])
+  call assert_equal([1, 1], ['Xf1'->buflisted(), 'Xf1'->bufloaded()])
   bwipeout! Xf1
 
   new Xf1

src/nvim/testdir/test_lambda.vim

@@ -61,7 +61,7 @@ endfunction
 
 function Test_lambda_fails()
   call assert_equal(3, {a, b -> a + b}(1, 2))
-  call assert_fails('echo {a, a -> a + a}(1, 2)', 'E15:')
+  call assert_fails('echo {a, a -> a + a}(1, 2)', 'E853:')
   call assert_fails('echo {a, b -> a + b)}(1, 2)', 'E15:')
 endfunc
 

src/nvim/testdir/test_match.vim

@@ -242,7 +242,7 @@ func Test_matchaddpos_otherwin()
         \]
   call assert_equal(expect, savematches)
 
-  call clearmatches(winid)
+  eval winid->clearmatches()
   call assert_equal([], getmatches(winid))
 
   call setmatches(savematches, winid)

src/nvim/testdir/test_method.vim

@@ -0,0 +1,159 @@
+" Tests for ->method()
+
+func Test_list_method()
+  let l = [1, 2, 3]
+  call assert_equal([1, 2, 3, 4], [1, 2, 3]->add(4))
+  eval l->assert_equal(l)
+  eval l->assert_equal(l, 'wrong')
+  eval l->assert_notequal([3, 2, 1])
+  eval l->assert_notequal([3, 2, 1], 'wrong')
+  call assert_equal(l, l->copy())
+  call assert_equal(l, l->deepcopy())
+  call assert_equal(1, l->count(2))
+  call assert_false(l->empty())
+  call assert_true([]->empty())
+  call assert_equal(579, ['123', '+', '456']->join()->eval())
+  call assert_equal([1, 2, 3, 4, 5], [1, 2, 3]->extend([4, 5]))
+  call assert_equal([1, 3], [1, 2, 3]->filter('v:val != 2'))
+  call assert_equal(2, l->get(1))
+  call assert_equal(1, l->index(2))
+  call assert_equal([0, 1, 2, 3], [1, 2, 3]->insert(0))
+  call assert_fails('eval l->items()', 'E715:')
+  call assert_equal('1 2 3', l->join())
+  call assert_fails('eval l->keys()', 'E715:')
+  call assert_equal(3, l->len())
+  call assert_equal([2, 3, 4], [1, 2, 3]->map('v:val + 1'))
+  call assert_equal(3, l->max())
+  call assert_equal(1, l->min())
+  call assert_equal(2, [1, 2, 3]->remove(1))
+  call assert_equal([1, 2, 3, 1, 2, 3], l->repeat(2))
+  call assert_equal([3, 2, 1], [1, 2, 3]->reverse())
+  call assert_equal([1, 2, 3, 4], [4, 2, 3, 1]->sort())
+  call assert_equal('[1, 2, 3]', l->string())
+  call assert_equal(v:t_list, l->type())
+  call assert_equal([1, 2, 3], [1, 1, 2, 3, 3]->uniq())
+  call assert_fails('eval l->values()', 'E715:')
+endfunc
+
+func Test_dict_method()
+  let d = #{one: 1, two: 2, three: 3}
+
+  call assert_equal(d, d->copy())
+  call assert_equal(d, d->deepcopy())
+  call assert_equal(1, d->count(2))
+  call assert_false(d->empty())
+  call assert_true({}->empty())
+  call assert_equal(#{one: 1, two: 2, three: 3, four: 4}, d->extend(#{four: 4}))
+  call assert_equal(#{one: 1, two: 2, three: 3}, d->filter('v:val != 4'))
+  call assert_equal(2, d->get('two'))
+  " Nvim doesn't support Blobs yet; expect a different emsg
+  " call assert_fails("let x = d->index(2)", 'E897:')
+  " call assert_fails("let x = d->insert(0)", 'E899:')
+  call assert_fails("let x = d->index(2)", 'E714:')
+  call assert_fails("let x = d->insert(0)", 'E686:')
+  call assert_true(d->has_key('two'))
+  call assert_equal([['one', 1], ['two', 2], ['three', 3]], d->items())
+  call assert_fails("let x = d->join()", 'E714:')
+  call assert_equal(['one', 'two', 'three'], d->keys())
+  call assert_equal(3, d->len())
+  call assert_equal(#{one: 2, two: 3, three: 4}, d->map('v:val + 1'))
+  call assert_equal(#{one: 1, two: 2, three: 3}, d->map('v:val - 1'))
+  call assert_equal(3, d->max())
+  call assert_equal(1, d->min())
+  call assert_equal(2, d->remove("two"))
+  let d.two = 2
+  call assert_fails('let x = d->repeat(2)', 'E731:')
+  " Nvim doesn't support Blobs yet; expect a different emsg
+  " call assert_fails('let x = d->reverse()', 'E899:')
+  call assert_fails('let x = d->reverse()', 'E686:')
+  call assert_fails('let x = d->sort()', 'E686:')
+  call assert_equal("{'one': 1, 'two': 2, 'three': 3}", d->string())
+  call assert_equal(v:t_dict, d->type())
+  call assert_fails('let x = d->uniq()', 'E686:')
+  call assert_equal([1, 2, 3], d->values())
+endfunc
+
+func Test_string_method()
+  eval '1 2 3'->split()->assert_equal(['1', '2', '3'])
+  eval '1 2 3'->split()->map({i, v -> str2nr(v)})->assert_equal([1, 2, 3])
+  eval 'ABC'->str2list()->assert_equal([65, 66, 67])
+  eval 'ABC'->strlen()->assert_equal(3)
+  eval "a\rb\ec"->strtrans()->assert_equal('a^Mb^[c')
+  eval "aあb"->strwidth()->assert_equal(4)
+  eval 'abc'->substitute('b', 'x', '')->assert_equal('axc')
+
+  eval 'abc'->printf('the %s arg')->assert_equal('the abc arg')
+endfunc
+
+func Test_method_append()
+  new
+  eval ['one', 'two', 'three']->append(1)
+  call assert_equal(['', 'one', 'two', 'three'], getline(1, '$'))
+
+  %del
+  let bnr = bufnr('')
+  wincmd w
+  eval ['one', 'two', 'three']->appendbufline(bnr, 1)
+  call assert_equal(['', 'one', 'two', 'three'], getbufline(bnr, 1, '$'))
+
+  exe 'bwipe! ' .. bnr
+endfunc
+
+func Test_method_funcref()
+  func Concat(one, two, three)
+    return a:one .. a:two .. a:three
+  endfunc
+  let FuncRef = function('Concat')
+  eval 'foo'->FuncRef('bar', 'tail')->assert_equal('foobartail')
+
+  " not enough arguments
+  call assert_fails("eval 'foo'->FuncRef('bar')", 'E119:')
+  " too many arguments
+  call assert_fails("eval 'foo'->FuncRef('bar', 'tail', 'four')", 'E118:')
+
+  let Partial = function('Concat', ['two'])
+  eval 'one'->Partial('three')->assert_equal('onetwothree')
+
+  " not enough arguments
+  call assert_fails("eval 'one'->Partial()", 'E119:')
+  " too many arguments
+  call assert_fails("eval 'one'->Partial('three', 'four')", 'E118:')
+
+  delfunc Concat
+endfunc
+
+func Test_method_float()
+  eval 1.234->string()->assert_equal('1.234')
+  eval -1.234->string()->assert_equal('-1.234')
+endfunc
+
+func Test_method_syntax()
+  eval [1, 2, 3]  ->sort( )
+  eval [1, 2, 3]  
+	\ ->sort(
+	\ )
+  call assert_fails('eval [1, 2, 3]-> sort()', 'E260:')
+  call assert_fails('eval [1, 2, 3]->sort ()', 'E274:')
+  call assert_fails('eval [1, 2, 3]-> sort ()', 'E260:')
+endfunc
+
+func Test_method_lambda()
+  eval "text"->{x -> x .. " extended"}()->assert_equal('text extended')
+  eval "text"->{x, y -> x .. " extended " .. y}('more')->assert_equal('text extended more')
+
+  call assert_fails('eval "text"->{x -> x .. " extended"} ()', 'E274:')
+
+  " todo: lambda accepts more arguments than it consumes
+  " call assert_fails('eval "text"->{x -> x .. " extended"}("more")', 'E99:')
+
+  " Nvim doesn't include test_refcount().
+  " let l = [1, 2, 3]
+  " eval l->{x -> x}()
+  " call assert_equal(1, test_refcount(l))
+endfunc
+
+func Test_method_not_supported()
+  call assert_fails('eval 123->changenr()', 'E276:')
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab

src/nvim/testdir/test_popup.vim

@@ -250,7 +250,7 @@ endfunc
 
 func Test_noinsert_complete()
   func! s:complTest1() abort
-    call complete(1, ['source', 'soundfold'])
+    eval ['source', 'soundfold']->complete(1)
     return ''
   endfunc
 
@@ -403,7 +403,7 @@ func DummyCompleteFour(findstart, base)
     return 0
   else
     call complete_add('four1')
-    call complete_add('four2')
+    eval 'four2'->complete_add()
     call complete_check()
     call complete_add('four3')
     call complete_add('four4')
@@ -989,7 +989,7 @@ func GetCompleteInfo()
   if empty(g:compl_what)
     let g:compl_info = complete_info()
   else
-    let g:compl_info = complete_info(g:compl_what)
+    let g:compl_info = g:compl_what->complete_info()
   endif
   return ''
 endfunc

src/nvim/testdir/test_syntax.vim

@@ -546,8 +546,8 @@ func Test_synstack_synIDtrans()
   call assert_equal([], synstack(1, 1))
 
   norm f/
-  call assert_equal(['cComment', 'cCommentStart'], map(synstack(line("."), col(".")), 'synIDattr(v:val, "name")'))
+  eval synstack(line("."), col("."))->map('synIDattr(v:val, "name")')->assert_equal(['cComment', 'cCommentStart'])
-  call assert_equal(['Comment', 'Comment'],	   map(synstack(line("."), col(".")), 'synIDattr(synIDtrans(v:val), "name")'))
+  eval synstack(line("."), col("."))->map('synIDattr(synIDtrans(v:val), "name")')->assert_equal(['Comment', 'Comment'])
 
   norm fA
   call assert_equal(['cComment'], map(synstack(line("."), col(".")), 'synIDattr(v:val, "name")'))

src/nvim/testdir/test_system.vim

@@ -7,10 +7,10 @@ func Test_System()
   if !executable('echo') || !executable('cat') || !executable('wc')
     return
   endif
-  let out = system('echo 123')
+  let out = 'echo 123'->system()
   call assert_equal("123\n", out)
 
-  let out = systemlist('echo 123')
+  let out = 'echo 123'->systemlist()
   if &shell =~# 'cmd.exe$'
     call assert_equal(["123\r"], out)
   else

src/nvim/testdir/test_user_func.vim

@@ -62,6 +62,14 @@ func Test_user_func()
   call assert_equal(9, g:retval)
   call assert_equal(333, g:FuncRef(333))
 
+  let g:retval = "nop"
+  call assert_equal('xxx4asdf', "xxx"->Table(4, "asdf"))
+  call assert_equal('fail', 45->Compute(0, "retval"))
+  call assert_equal('nop', g:retval)
+  call assert_equal('ok', 45->Compute(5, "retval"))
+  call assert_equal(9, g:retval)
+  " call assert_equal(333, 333->g:FuncRef())
+
   enew
 
   normal oXX+-XX
@@ -150,6 +158,14 @@ func Test_default_arg()
 	\ execute('func Args2'))
 endfunc
 
+func s:addFoo(lead)
+  return a:lead .. 'foo'
+endfunc
+
+func Test_user_method()
+  eval 'bar'->s:addFoo()->assert_equal('barfoo')
+endfunc
+
 func Test_failed_call_in_try()
   try | call UnknownFunc() | catch | endtry
 endfunc

src/nvim/testdir/test_vimscript.vim

@@ -1372,6 +1372,7 @@ func Test_bitwise_functions()
     " and
     call assert_equal(127, and(127, 127))
     call assert_equal(16, and(127, 16))
+    eval 127->and(16)->assert_equal(16)
     call assert_equal(0, and(127, 128))
     call assert_fails("call and(1.0, 1)", 'E805:')
     call assert_fails("call and([], 1)", 'E745:')
@@ -1382,6 +1383,7 @@ func Test_bitwise_functions()
     " or
     call assert_equal(23, or(16, 7))
     call assert_equal(15, or(8, 7))
+    eval 8->or(7)->assert_equal(15)
     call assert_equal(123, or(0, 123))
     call assert_fails("call or(1.0, 1)", 'E805:')
     call assert_fails("call or([], 1)", 'E745:')
@@ -1392,6 +1394,7 @@ func Test_bitwise_functions()
     " xor
     call assert_equal(0, xor(127, 127))
     call assert_equal(111, xor(127, 16))
+    eval 127->xor(16)->assert_equal(111)
     call assert_equal(255, xor(127, 128))
     call assert_fails("call xor(1.0, 1)", 'E805:')
     call assert_fails("call xor([], 1)", 'E745:')
@@ -1401,6 +1404,7 @@ func Test_bitwise_functions()
     call assert_fails("call xor(1, {})", 'E728:')
     " invert
     call assert_equal(65408, and(invert(127), 65535))
+    eval 127->invert()->and(65535)->assert_equal(65408)
     call assert_equal(65519, and(invert(16), 65535))
     call assert_equal(65407, and(invert(128), 65535))
     call assert_fails("call invert(1.0)", 'E805:')

test/functional/core/startup_spec.lua

@@ -247,9 +247,9 @@ describe('startup', function()
     [[" -u NONE -i NONE --cmd "set noruler" --cmd "let g:foo = g:bar"')]])
     screen:expect([[
       ^                                                            |
+                                                                  |
       Error detected while processing pre-vimrc command line:     |
       E121: Undefined variable: g:bar                             |
-      E15: Invalid expression: g:bar                              |
       Press ENTER or type command to continue                     |
                                                                   |
     ]])

test/functional/eval/null_spec.lua

@@ -53,7 +53,7 @@ describe('NULL', function()
 
     -- Correct behaviour
     null_expr_test('can be indexed with error message for empty list', 'L[0]',
-                   'E684: list index out of range: 0\nE15: Invalid expression: L[0]', nil)
+                   'E684: list index out of range: 0', nil)
     null_expr_test('can be splice-indexed', 'L[:]', 0, {})
     null_expr_test('is not locked', 'islocked("v:_null_list")', 0, 0)
     null_test('is accepted by :for', 'for x in L|throw x|endfor', 0)
@@ -68,7 +68,7 @@ describe('NULL', function()
     null_expr_test('can be copied', 'copy(L)', 0, {})
     null_expr_test('can be deepcopied', 'deepcopy(L)', 0, {})
     null_expr_test('does not crash when indexed', 'L[1]',
-                        'E684: list index out of range: 1\nE15: Invalid expression: L[1]', nil)
+                        'E684: list index out of range: 1', nil)
     null_expr_test('does not crash call()', 'call("arglistid", L)', 0, 0)
     null_expr_test('does not crash col()', 'col(L)', 0, 0)
     null_expr_test('does not crash virtcol()', 'virtcol(L)', 0, 0)
@@ -135,7 +135,7 @@ describe('NULL', function()
   end)
   describe('dict', function()
     it('does not crash when indexing NULL dict', function()
-      eq('\nE716: Key not present in Dictionary: "test"\nE15: Invalid expression: v:_null_dict.test',
+      eq('\nE716: Key not present in Dictionary: "test"',
          redir_exec('echo v:_null_dict.test'))
     end)
     null_expr_test('makes extend error out', 'extend(D, {})', 'E742: Cannot change value of extend() argument', 0)

test/functional/legacy/assert_spec.lua

@@ -26,6 +26,14 @@ describe('assert function:', function()
       call('assert_beeps', 'normal 0')
       expected_errors({'command did not beep: normal 0'})
     end)
+
+    it('can be used as a method', function()
+      local tmpname = source [[
+        call assert_equal(0, 'normal h'->assert_beeps())
+        call assert_equal(1, 'normal 0'->assert_beeps())
+      ]]
+      expected_errors({tmpname .. ' line 2: command did not beep: normal 0'})
+    end)
   end)
 
   -- assert_equal({expected}, {actual}, [, {msg}])
@@ -133,6 +141,14 @@ describe('assert function:', function()
       call('assert_false', {})
       expected_errors({'Expected False but got []'})
     end)
+
+    it('can be used as a method', function()
+      local tmpname = source [[
+        call assert_equal(0, v:false->assert_false())
+        call assert_equal(1, 123->assert_false())
+      ]]
+      expected_errors({tmpname .. ' line 2: Expected False but got 123'})
+    end)
   end)
 
   -- assert_true({actual}, [, {msg}])
@@ -148,6 +164,14 @@ describe('assert function:', function()
       eq(1, call('assert_true', 1.5))
       expected_errors({'Expected True but got 1.5'})
     end)
+
+    it('can be used as a method', function()
+      local tmpname = source [[
+        call assert_equal(0, v:true->assert_true())
+        call assert_equal(1, 0->assert_true())
+      ]]
+      expected_errors({tmpname .. ' line 2: Expected True but got 0'})
+    end)
   end)
 
   describe('v:errors', function()
@@ -223,6 +247,15 @@ describe('assert function:', function()
       call('assert_match', 'bar.*foo', 'foobar', 'wrong')
       expected_errors({"wrong: Pattern 'bar.*foo' does not match 'foobar'"})
     end)
+
+    it('can be used as a method', function()
+      local tmpname = source [[
+        call assert_equal(1, 'foobar'->assert_match('bar.*foo', 'wrong'))
+      ]]
+      expected_errors({
+        tmpname .. " line 1: wrong: Pattern 'bar.*foo' does not match 'foobar'"
+      })
+    end)
   end)
 
   -- assert_notmatch({pat}, {text}[, {msg}])
@@ -237,6 +270,13 @@ describe('assert function:', function()
       call('assert_notmatch', 'foo', 'foobar')
       expected_errors({"Pattern 'foo' does match 'foobar'"})
     end)
+
+    it('can be used as a method', function()
+      local tmpname = source [[
+        call assert_equal(1, 'foobar'->assert_notmatch('foo'))
+      ]]
+      expected_errors({tmpname .. " line 1: Pattern 'foo' does match 'foobar'"})
+    end)
   end)
 
   -- assert_fails({cmd}, [, {error}])
@@ -267,6 +307,15 @@ describe('assert function:', function()
       eq(1, eval([[assert_fails('echo', '', 'echo command')]]))
       expected_errors({'command did not fail: echo command'})
     end)
+
+    it('can be used as a method', function()
+      local tmpname = source [[
+        call assert_equal(1, 'echo'->assert_fails('', 'echo command'))
+      ]]
+      expected_errors({
+        tmpname .. ' line 1: command did not fail: echo command'
+      })
+    end)
   end)
 
   -- assert_inrange({lower}, {upper}, {actual}[, {msg}])
@@ -292,6 +341,15 @@ describe('assert function:', function()
       eq('Vim(call):E119: Not enough arguments for function: assert_inrange',
          exc_exec("call assert_inrange(1, 1)"))
     end)
+
+    it('can be used as a method', function()
+      local tmpname = source [[
+        call assert_equal(0, 5->assert_inrange(5, 7))
+        call assert_equal(0, 7->assert_inrange(5, 7))
+        call assert_equal(1, 8->assert_inrange(5, 7))
+      ]]
+      expected_errors({tmpname .. ' line 3: Expected range 5 - 7, but got 8'})
+    end)
   end)
 
   -- assert_report({msg})
@@ -302,6 +360,13 @@ describe('assert function:', function()
       command('call remove(v:errors, 0)')
       expected_empty()
     end)
+
+    it('can be used as a method', function()
+      local tmpname = source [[
+        call assert_equal(1, 'also wrong'->assert_report())
+      ]]
+      expected_errors({tmpname .. ' line 1: also wrong'})
+    end)
   end)
 
   -- assert_exception({cmd}, [, {error}])

test/functional/lua/luaeval_spec.lua

@@ -481,6 +481,21 @@ describe('v:lua', function()
        pcall_err(eval, 'v:lua.mymod.crashy()'))
   end)
 
+  it('works when called as a method', function()
+    eq(123, eval('110->v:lua.foo(13)'))
+    eq(true, exec_lua([[return _G.val == nil]]))
+
+    eq(321, eval('300->v:lua.foo(21, "boop")'))
+    eq("boop", exec_lua([[return _G.val]]))
+
+    eq(NIL, eval('"there"->v:lua.mymod.noisy()'))
+    eq("hey there", meths.get_current_line())
+    eq({5, 10, 15, 20}, eval('[[1], [2, 3], [4]]->v:lua.vim.tbl_flatten()->map({_, v -> v * 5})'))
+
+    eq("Vim:E5108: Error executing lua [string \"<nvim>\"]:0: attempt to call global 'nonexistent' (a nil value)",
+       pcall_err(eval, '"huh?"->v:lua.mymod.crashy()'))
+  end)
+
   it('works in :call', function()
     command(":call v:lua.mymod.noisy('command')")
     eq("hey command", meths.get_current_line())
@@ -518,8 +533,15 @@ describe('v:lua', function()
 
     eq("Vim:E15: Invalid expression: v:['lua'].foo()", pcall_err(eval, "v:['lua'].foo()"))
     eq("Vim(call):E461: Illegal variable name: v:['lua']", pcall_err(command, "call v:['lua'].baar()"))
+    eq("Vim:E117: Unknown function: v:lua", pcall_err(eval, "v:lua()"))
 
     eq("Vim(let):E46: Cannot change read-only variable \"v:['lua']\"", pcall_err(command, "let v:['lua'] = 'xx'"))
     eq("Vim(let):E46: Cannot change read-only variable \"v:lua\"", pcall_err(command, "let v:lua = 'xx'"))
+
+    eq("Vim:E107: Missing parentheses: v:lua.func", pcall_err(eval, "'bad'->v:lua.func"))
+    eq("Vim:E274: No white space allowed before parenthesis", pcall_err(eval, "'bad'->v:lua.func ()"))
+    eq("Vim:E107: Missing parentheses: v:lua", pcall_err(eval, "'bad'->v:lua"))
+    eq("Vim:E117: Unknown function: v:lua", pcall_err(eval, "'bad'->v:lua()"))
+    eq("Vim:E15: Invalid expression: v:lua.()", pcall_err(eval, "'bad'->v:lua.()"))
   end)
 end)

test/functional/provider/clipboard_spec.lua

@@ -653,14 +653,12 @@ describe('clipboard (with fake clipboard.vim)', function()
       '',
       '',
       'E121: Undefined variable: doesnotexist',
-      'E15: Invalid expression: doesnotexist',
     }, 'v'}, eval("g:test_clip['*']"))
     feed_command(':echo "Howdy!"')
     eq({{
       '',
       '',
       'E121: Undefined variable: doesnotexist',
-      'E15: Invalid expression: doesnotexist',
       '',
       'Howdy!',
     }, 'v'}, eval("g:test_clip['*']"))