patch 8.1.1807: more functions can be used as a method

Problem:    More functions can be used as a method.
Solution:   Add append(), appendbufline(), assert_equal(), etc.
            Also add the :eval command.

runtime/doc/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 8.1.  Last change: 2019 Jul 30
+*eval.txt*	For Vim version 8.1.  Last change: 2019 Aug 04
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -840,12 +840,14 @@ 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
@@ -1111,10 +1113,10 @@ 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
-	expr9.name[expr1]
-	expr9(expr1, ...)[expr1].name
-	expr9->(expr1, ...)[expr1]
+	expr8[expr1].name
+	expr8.name[expr1]
+	expr8(expr1, ...)[expr1].name
+	expr8->(expr1, ...)[expr1]
 Evaluation is always from left to right.
 
 
@@ -1217,10 +1219,17 @@ When expr8 is a |Funcref| type variable, invoke the function it refers to.
 
 expr8->name([args])	method call			*method*
 
-For global methods this is the same as: >
+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".
 
+"->name(" must not contain white space.  There can be white space before "->"
+and after the "(".
+
+This allows for chaining, using the type that the method returns: >
+	mylist->filter(filterexpr)->map(mapexpr)->sort()->join()
+<
+
 							*expr9*
 number
 ------
@@ -2906,6 +2915,10 @@ 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}.
 
@@ -2921,8 +2934,11 @@ appendbufline({expr}, {lnum}, {text})			*appendbufline()*
 		error message is given. Example: >
 			:let failed = appendbufline(13, 0, "# THE START")
 <
-							*argc()*
-argc([{winid}])
+		Can also be used as a |method| after a List: >
+			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
@@ -3762,6 +3778,9 @@ eval({string})	Evaluate {string} and return the result.  Especially useful to
 		of 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,
@@ -4115,7 +4134,12 @@ 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_readable()*
+		{file} is used as-is, you may want to expand wildcards first: >
+			echo filereadable('~/.vimrc')
+			0
+			echo filereadable(expand('~/.vimrc'))
+			1
+<							*file_readable()*
 		Obsolete name: file_readable().
 
 
@@ -7998,9 +8022,9 @@ sha256({string})						*sha256()*
 
 shellescape({string} [, {special}])			*shellescape()*
 		Escape {string} for use as a shell command argument.
-		On MS-Windows and MS-DOS, when 'shellslash' is not set, it
-		will enclose {string} in double quotes and double all double
-		quotes within {string}.
+		On MS-Windows, when 'shellslash' is not set, it will enclose
+		{string} in double quotes and double all double quotes within
+		{string}.
 		Otherwise it will enclose {string} in single quotes and
 		replace all "'" with "'\''".
 
@@ -10047,6 +10071,10 @@ 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, but does
+allow for method chaining, e.g.: >
+	eval GetList()->Filter()->append('$')
+
 
 AUTOMATICALLY LOADING FUNCTIONS ~
 							*autoload-functions*
@@ -10498,6 +10526,20 @@ text...
 			Unlock the internal variable {name}.  Does the
 			opposite of |:lockvar|.
 
+							*:eval*
+:eval {expr}		Evaluate {expr} and discard the result.  Example: >
+				:eval Getlist()->Filter()->append('$')
+
+<			The expression is supposed to have a side effect,
+			since the resulting value is not used.  In the example
+			the `append()` call appends the List with text to the
+			buffer.  This is similar to `:call` but works with any
+			expression.
+
+			The command can be shortened to `:ev` or `:eva`, but
+			these are hard to recognize and therefore not to be
+			used.
+
 
 :if {expr1}			*:if* *:end* *:endif* *:en* *E171* *E579* *E580*
 :en[dif]		Execute the commands until the next matching ":else"

runtime/doc/testing.txt

@@ -1,4 +1,4 @@
-*testing.txt*	For Vim version 8.1.  Last change: 2019 Jul 28
+*testing.txt*	For Vim version 8.1.  Last change: 2019 Aug 04
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -222,7 +222,11 @@ 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|.
@@ -294,7 +298,10 @@ 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}.