feat(eval/method): partially port v8.1.1993

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.
https://github.com/vim/vim/commit/196b4664432f932625cfb6371dc42c24efe6c203

server2client requires +clientserver, which hasn't been ported yet.
The eval.txt docs and test_clientserver.vim tests for server2client already exist, so include those
changes.

test_bufline.vim: Test for setbufline requires v8.1.1189 (which was reverted in #10848).

13 files changed, 106 insertions, 27 deletions

diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 02ff9fc591..74b0351dbe 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -5854,7 +5854,7 @@ histadd({history}, {item})				*histadd()*
 
 		Can also be used as a |method|, the base is used for the
 		second argument: >
-			GetPattern()->histadd('search')
+			GetHistory()->histadd('search')
 
 histdel({history} [, {item}])				*histdel()*
 		Clear {history}, i.e. delete all its entries.  See |hist-names|
@@ -8072,6 +8072,9 @@ screenattr({row}, {col})					*screenattr()*
 		arbitrary number that can only be used to compare to the
 		attribute at other positions.
 
+		Can also be used as a |method|: >
+			GetRow()->screenattr(col)
+
 screenchar({row}, {col})					*screenchar()*
 		The result is a Number, which is the character at position
 		[row, col] on the screen.  This works for every possible
@@ -8082,6 +8085,9 @@ screenchar({row}, {col})					*screenchar()*
 		This is mainly to be used for testing.
 		Returns -1 when row or col is out of range.
 
+		Can also be used as a |method|: >
+			GetRow()->screenchar(col)
+
 screenchars({row}, {col})					*screenchars()*
 		The result is a List of Numbers.  The first number is the same
 		as what |screenchar()| returns.  Further numbers are
@@ -8089,6 +8095,9 @@ screenchars({row}, {col})					*screenchars()*
 		This is mainly to be used for testing.
 		Returns an empty List when row or col is out of range.
 
+		Can also be used as a |method|: >
+			GetRow()->screenchars(col)
+
 screencol()							*screencol()*
 		The result is a Number, which is the current screen column of
 		the cursor. The leftmost column has number 1.
@@ -8124,6 +8133,9 @@ screenpos({winid}, {lnum}, {col})				*screenpos()*
  		right position and use |screencol()| to get the value with
  		|conceal| taken into account.
 
+		Can also be used as a |method|: >
+			GetWinid()->screenpos(lnum, col)
+
 screenrow()							*screenrow()*
 		The result is a Number, which is the current screen row of the
 		cursor.  The top line has number one.
@@ -8140,6 +8152,9 @@ screenstring({row}, {col})					*screenstring()*
 		This is mainly to be used for testing.
 		Returns an empty String when row or col is out of range.
 
+		Can also be used as a |method|: >
+			GetRow()->screenstring(col)
+
 search({pattern} [, {flags} [, {stopline} [, {timeout}]]])	*search()*
 		Search for regexp pattern {pattern}.  The search starts at the
 		cursor position (you can use |cursor()| to set it).
@@ -8230,6 +8245,8 @@ search({pattern} [, {flags} [, {stopline} [, {timeout}]]])	*search()*
 		without the 'e' flag if the cursor is on the "f" of "if".
 		The 'n' flag tells the function not to move the cursor.
 
+		Can also be used as a |method|: >
+			GetPattern()->search()
 
 searchcount([{options}])					*searchcount()*
 		Get or update the last search count, like what is displayed
@@ -8369,6 +8386,9 @@ searchdecl({name} [, {global} [, {thisblock}]])			*searchdecl()*
 			   echo getline('.')
 			endif
 <
+		Can also be used as a |method|: >
+			GetName()->searchdecl()
+<
 							*searchpair()*
 searchpair({start}, {middle}, {end} [, {flags} [, {skip}
 				[, {stopline} [, {timeout}]]]])
@@ -8483,6 +8503,9 @@ searchpos({pattern} [, {flags} [, {stopline} [, {timeout}]]])	*searchpos()*
 <		In this example "submatch" is 2 when a lowercase letter is
 		found |/\l|, 3 when an uppercase letter is found |/\u|.
 
+		Can also be used as a |method|: >
+			GetPattern()->searchpos()
+
 server2client({clientid}, {string})			*server2client()*
 		Send a reply string to {clientid}.  The most recent {clientid}
 		that sent a string can be retrieved with expand("<client>").
@@ -8494,6 +8517,9 @@ server2client({clientid}, {string})			*server2client()*
 		See also |clientserver|.
 		Example: >
 			:echo server2client(expand("<client>"), "HELLO")
+
+<		Can also be used as a |method|: >
+			GetClientId()->server2client(string)
 <
 serverlist()						*serverlist()*
 		Returns a list of server addresses, or empty if all servers
@@ -8559,6 +8585,9 @@ setbufline({buf}, {lnum}, {text})			*setbufline()*
 		If {buf} is not a valid buffer or {lnum} is not valid, an
 		error message is given.
 
+		Can also be used as a |method|: >
+			GetText()->setbufline(buf, lnum)
+
 setbufvar({buf}, {varname}, {val})			*setbufvar()*
 		Set option or local variable {varname} in buffer {buf} to
 		{val}.
@@ -8573,6 +8602,9 @@ setbufvar({buf}, {varname}, {val})			*setbufvar()*
 			:call setbufvar("todo", "myvar", "foobar")
 <		This function is not available in the |sandbox|.
 
+		Can also be used as a |method|: >
+			GetValue()->setbufvar(buf, varname)
+
 setcharsearch({dict})					*setcharsearch()*
 		Set the current character search information to {dict},
 		which contains one or more of the following entries:
@@ -8593,6 +8625,9 @@ setcharsearch({dict})					*setcharsearch()*
 			:call setcharsearch(prevsearch)
 <		Also see |getcharsearch()|.
 
+		Can also be used as a |method|: >
+			SavedSearch()->setcharsearch()
+
 setcmdpos({pos})					*setcmdpos()*
 		Set the cursor position in the command line to byte position
 		{pos}.  The first position is 1.
@@ -8608,6 +8643,9 @@ setcmdpos({pos})					*setcmdpos()*
 		Returns FALSE when successful, TRUE when not editing the
 		command line.
 
+		Can also be used as a |method|: >
+			GetPos()->setcmdpos()
+
 setenv({name}, {val})						*setenv()*
 		Set environment variable {name} to {val}.  Example: >
 			call setenv('HOME', '/home/myhome')
@@ -8615,6 +8653,9 @@ setenv({name}, {val})						*setenv()*
 <		When {val} is |v:null| the environment variable is deleted.
 		See also |expr-env|.
 
+		Can also be used as a |method|, passing the value as the base: >
+			GetPath()->setenv('PATH')
+
 setfperm({fname}, {mode})				*setfperm()* *chmod*
 		Set the file permissions for {fname} to {mode}.
 		{mode} must be a string with 9 characters.  It is of the form
@@ -8660,6 +8701,9 @@ setline({lnum}, {text})					*setline()*
 
 <		Note: The '[ and '] marks are not set.
 
+		Can also be used as a |method|, passing the text as the base: >
+			GetText()->setline(lnum)
+
 setloclist({nr}, {list}[, {action}[, {what}]])		*setloclist()*
 		Create or replace or add to the location list for window {nr}.
 		{nr} can be the window number or the |window-ID|.
diff --git a/src/nvim/eval.lua b/src/nvim/eval.lua
index dfc51d80af..d6b285eab0 100644
--- a/src/nvim/eval.lua
+++ b/src/nvim/eval.lua
@@ -291,29 +291,29 @@ return {
     rpcstart={args={1, 2}},
     rpcstop={args=1},
     rubyeval={args=1, base=1},
-    screenattr={args=2},
-    screenchar={args=2},
-    screenchars={args=2},
+    screenattr={args=2, base=1},
+    screenchar={args=2, base=1},
+    screenchars={args=2, base=1},
     screencol={},
-    screenpos={args=3},
+    screenpos={args=3, base=1},
     screenrow={},
-    screenstring={args=2},
-    search={args={1, 4}},
+    screenstring={args=2, base=1},
+    search={args={1, 4}, base=1},
     searchcount={args={0,1}},
-    searchdecl={args={1, 3}},
+    searchdecl={args={1, 3}, base=1},
     searchpair={args={3, 7}},
     searchpairpos={args={3, 7}},
-    searchpos={args={1, 4}},
+    searchpos={args={1, 4}, base=1},
     serverlist={},
     serverstart={args={0, 1}},
     serverstop={args=1},
-    setbufline={args=3},
-    setbufvar={args=3},
-    setcharsearch={args=1},
-    setcmdpos={args=1},
-    setenv={args=2},
+    setbufline={args=3, base=3},
+    setbufvar={args=3, base=3},
+    setcharsearch={args=1, base=1},
+    setcmdpos={args=1, base=1},
+    setenv={args=2, base=2},
     setfperm={args=2, base=1},
-    setline={args=2},
+    setline={args=2, base=2},
     setloclist={args={2, 4}},
     setmatches={args={1, 2}},
     setpos={args=2},
diff --git a/src/nvim/testdir/test_charsearch.vim b/src/nvim/testdir/test_charsearch.vim
index 17a49e02be..6f09e85a42 100644
--- a/src/nvim/testdir/test_charsearch.vim
+++ b/src/nvim/testdir/test_charsearch.vim
@@ -20,7 +20,7 @@ func Test_charsearch()
   " check that setcharsearch() changes the settings.
   3
   normal! ylfep
-  call setcharsearch({'char': 'k'})
+  eval {'char': 'k'}->setcharsearch()
   normal! ;p
   call setcharsearch({'forward': 0})
   normal! $;p
diff --git a/src/nvim/testdir/test_clientserver.vim b/src/nvim/testdir/test_clientserver.vim
index f3db472b03..922803438f 100644
--- a/src/nvim/testdir/test_clientserver.vim
+++ b/src/nvim/testdir/test_clientserver.vim
@@ -82,7 +82,7 @@ func Test_client_server()
   call remote_send(name, ":call server2client(expand('<client>'), 'got it')\<CR>", 'g:myserverid')
   call assert_equal('got it', g:myserverid->remote_read(2))
 
-  call remote_send(name, ":call server2client(expand('<client>'), 'another')\<CR>", 'g:myserverid')
+  call remote_send(name, ":eval expand('<client>')->server2client('another')\<CR>", 'g:myserverid')
   let peek_result = 'nothing'
   let r = g:myserverid->remote_peek('peek_result')
   " unpredictable whether the result is already available.
diff --git a/src/nvim/testdir/test_cmdline.vim b/src/nvim/testdir/test_cmdline.vim
index 75e17b47b8..49a5386337 100644
--- a/src/nvim/testdir/test_cmdline.vim
+++ b/src/nvim/testdir/test_cmdline.vim
@@ -905,7 +905,7 @@ func Test_setcmdpos()
   call assert_equal('"12ab', @:)
 
   " setcmdpos() returns 1 when not editing the command line.
-  call assert_equal(1, setcmdpos(3))
+  call assert_equal(1, 3->setcmdpos())
 endfunc
 
 func Test_cmdline_overstrike()
diff --git a/src/nvim/testdir/test_cursor_func.vim b/src/nvim/testdir/test_cursor_func.vim
index 46847e0663..a2482d95c4 100644
--- a/src/nvim/testdir/test_cursor_func.vim
+++ b/src/nvim/testdir/test_cursor_func.vim
@@ -86,7 +86,7 @@ func Test_screenpos()
   call assert_equal({'row': winrow,
     \ 'col': wincol + 13,
     \ 'curscol': wincol + 13,
-    \ 'endcol': wincol + 13}, screenpos(winid, 1, 7))
+    \ 'endcol': wincol + 13}, winid->screenpos(1, 7))
   call assert_equal({'row': winrow + 2,
     \ 'col': wincol + 1,
     \ 'curscol': wincol + 1,
diff --git a/src/nvim/testdir/test_diffmode.vim b/src/nvim/testdir/test_diffmode.vim
index 61da3cbcaa..3a0c615cf6 100644
--- a/src/nvim/testdir/test_diffmode.vim
+++ b/src/nvim/testdir/test_diffmode.vim
@@ -387,7 +387,7 @@ func Test_diffoff()
   call setline(1, ['One', '', 'Two', 'Three'])
   diffthis
   redraw
-  call assert_notequal(normattr, screenattr(1, 1))
+  call assert_notequal(normattr, 1->screenattr(1))
   diffoff!
   redraw
   call assert_equal(normattr, screenattr(1, 1))
diff --git a/src/nvim/testdir/test_environ.vim b/src/nvim/testdir/test_environ.vim
index cc15b63824..dd34983ee5 100644
--- a/src/nvim/testdir/test_environ.vim
+++ b/src/nvim/testdir/test_environ.vim
@@ -22,7 +22,7 @@ endfunc
 
 func Test_setenv()
   unlet! $TESTENV
-  call setenv('TEST ENV', 'foo')
+  eval 'foo'->setenv('TEST ENV')
   call assert_equal('foo', getenv('TEST ENV'))
   call setenv('TEST ENV', v:null)
   call assert_equal(v:null, getenv('TEST ENV'))
diff --git a/src/nvim/testdir/test_functions.vim b/src/nvim/testdir/test_functions.vim
index 4a2ade5afa..2fcdd94188 100644
--- a/src/nvim/testdir/test_functions.vim
+++ b/src/nvim/testdir/test_functions.vim
@@ -346,7 +346,7 @@ func Test_setbufvar_options()
   wincmd h
   let wh = winheight(0)
   let dummy_buf = bufnr('dummy_buf2', v:true)
-  call setbufvar(dummy_buf, '&buftype', 'nofile')
+  eval 'nofile'->setbufvar(dummy_buf, '&buftype')
   execute 'belowright vertical split #' . dummy_buf
   call assert_equal(wh, winheight(0))
 
@@ -1330,7 +1330,7 @@ func Test_func_range_with_edit()
   " is invalid in that buffer.
   call writefile(['just one line'], 'Xfuncrange2')
   new
-  call setline(1, 10->range())
+  eval 10->range()->setline(1)
   write Xfuncrange1
   call assert_fails('5,8call EditAnotherFile()', 'E16:')
 
diff --git a/src/nvim/testdir/test_matchadd_conceal_utf8.vim b/src/nvim/testdir/test_matchadd_conceal_utf8.vim
index 34c8c49dd5..7bfac13ad8 100644
--- a/src/nvim/testdir/test_matchadd_conceal_utf8.vim
+++ b/src/nvim/testdir/test_matchadd_conceal_utf8.vim
@@ -6,7 +6,7 @@ endif
 function! s:screenline(lnum) abort
   let line = []
   for c in range(1, winwidth(0))
-    call add(line, nr2char(screenchar(a:lnum, c)))
+    call add(line, nr2char(a:lnum->screenchar(c)))
   endfor
   return s:trim(join(line, ''))
 endfunction
diff --git a/src/nvim/testdir/test_search.vim b/src/nvim/testdir/test_search.vim
index 7570049e7c..c796f1f676 100644
--- a/src/nvim/testdir/test_search.vim
+++ b/src/nvim/testdir/test_search.vim
@@ -1315,7 +1315,7 @@ func Test_search_match_at_curpos()
 
   normal gg
 
-  call search('foobar', 'c')
+  eval 'foobar'->search('c')
   call assert_equal([1, 1], [line('.'), col('.')])
 
   normal j
@@ -1354,6 +1354,41 @@ func Test_search_display_pattern()
   endif
 endfunc
 
+func Test_searchdecl()
+  let lines =<< trim END
+     int global;
+
+     func()
+     {
+       int global;
+       if (cond) {
+	 int local;
+       }
+       int local;
+       // comment
+     }
+  END
+  new
+  call setline(1, lines)
+  10
+  call assert_equal(0, searchdecl('local', 0, 0))
+  call assert_equal(7, getcurpos()[1])
+
+  10
+  call assert_equal(0, 'local'->searchdecl(0, 1))
+  call assert_equal(9, getcurpos()[1])
+
+  10
+  call assert_equal(0, searchdecl('global'))
+  call assert_equal(5, getcurpos()[1])
+
+  10
+  call assert_equal(0, searchdecl('global', 1))
+  call assert_equal(1, getcurpos()[1])
+
+  bwipe!
+endfunc
+
 func Test_search_special()
   " this was causing illegal memory access and an endless loop
   set t_PE=
diff --git a/src/nvim/testdir/test_utf8.vim b/src/nvim/testdir/test_utf8.vim
index da72da087f..1f2cdde5cf 100644
--- a/src/nvim/testdir/test_utf8.vim
+++ b/src/nvim/testdir/test_utf8.vim
@@ -69,7 +69,7 @@ func Test_screenchar_utf8()
   call setline(1, ["ABC\u0308"])
   redraw
   call assert_equal([0x0041], screenchars(1, 1))
-  call assert_equal([0x0042], screenchars(1, 2))
+  call assert_equal([0x0042], 1->screenchars(2))
   call assert_equal([0x0043, 0x0308], screenchars(1, 3))
   call assert_equal("A", screenstring(1, 1))
   call assert_equal("B", screenstring(1, 2))
diff --git a/test/functional/legacy/searchpos_spec.lua b/test/functional/legacy/searchpos_spec.lua
index 60f1edcd3f..fc18341c38 100644
--- a/test/functional/legacy/searchpos_spec.lua
+++ b/test/functional/legacy/searchpos_spec.lua
@@ -17,7 +17,7 @@ describe('searchpos', function()
     call('cursor', 1, 1)
     eq({1, 1, 2}, eval([[searchpos('\%(\([a-z]\)\|\_.\)\{-}xyz', 'pcW')]]))
     call('cursor', 1, 2)
-    eq({2, 1, 1}, eval([[searchpos('\%(\([a-z]\)\|\_.\)\{-}xyz', 'pcW')]]))
+    eq({2, 1, 1}, eval([['\%(\([a-z]\)\|\_.\)\{-}xyz'->searchpos('pcW')]]))
 
     command('set cpo-=c')
     call('cursor', 1, 2)