eval.txt: Update Vim 8.2.4987

Author: tsuyoshicho

en/eval.txt

@@ -1,4 +1,4 @@
-*eval.txt*	For Vim version 8.2.  Last change: 2022 Apr 17
+*eval.txt*	For Vim version 8.2.  Last change: 2022 May 13
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -523,8 +523,8 @@ only appear once.  Examples: >
 A key is always a String.  You can use a Number, it will be converted to a
 String automatically.  Thus the String '4' and the number 4 will find the same
 entry.  Note that the String '04' and the Number 04 are different, since the
-Number will be converted to the String '4'.  The empty string can also be used
-as a key.
+Number will be converted to the String '4', leading zeros are dropped.  The
+empty string can also be used as a key.
 
 In |Vim9| script literaly keys can be used if the key consists of alphanumeric
 characters, underscore and dash, see |vim9-literal-dict|.
@@ -534,7 +534,8 @@ legacy script.  This does require the key to consist only of ASCII letters,
 digits, '-' and '_'.  Example: >
 	:let mydict = #{zero: 0, one_key: 1, two-key: 2, 333: 3}
 Note that 333 here is the string "333".  Empty keys are not possible with #{}.
-In |Vim9| script the #{} form cannot be used.
+In |Vim9| script the #{} form cannot be used because it can be confused with
+the start of a comment.
 
 A value can be any expression.  Using a Dictionary for a value creates a
 nested Dictionary: >
@@ -1533,14 +1534,22 @@ allowing the inclusion of Vim script expressions (see |expr1|).  Any
 expression returning a value can be enclosed between curly braces.  The value
 is converted to a string.  All the text and results of the expressions
 are concatenated to make a new string.
-
+								*E1278*
 To include an opening brace '{' or closing brace '}' in the string content
-double it.
+double it.  For double quoted strings using a backslash also works.  A single
+closing brace '}' will result in an error.
 
 Examples: >
 	let your_name = input("What's your name? ")
+<	What's your name?  Peter ~
+>
+	echo
 	echo $"Hello, {your_name}!"
-	echo $"The square root of 9 is {sqrt(9)}"
+<	Hello, Peter! ~
+>
+	echo $"The square root of {{9}} is {sqrt(9)}"
+<	The square root of {9} is 3.0 ~
+
 
 option						*expr-option* *E112* *E113*
 ------
@@ -2951,7 +2960,7 @@ the "autoload" directory in 'runtimepath'.
 
 Using an autocommand ~
 
-This is introduced in the user manual, section |41.14|.
+This is introduced in the user manual, section |51.4|.
 
 The autocommand is useful if you have a plugin that is a long Vim script file.
 You can define the autocommand and quickly quit the script with `:finish`.
@@ -2969,7 +2978,7 @@ The file "~/vim/bufnetfuncs.vim" should then define functions that start with
 
 Using an autoload script ~
 							*autoload* *E746*
-This is introduced in the user manual, section |41.15|.
+This is introduced in the user manual, section |51.5|.
 
 Using a script in the "autoload" directory is simpler, but requires using
 exactly the right file name.  A function that can be autoloaded has a name
@@ -3252,20 +3261,20 @@ text...
 			{endmarker}.
 
 			If "eval" is not specified, then each line of text is
-			used as a |literal-string|.  If "eval" is specified,
-			then any Vim expression in the form ``={expr}`` is
-			evaluated and the result replaces the expression.
+			used as a |literal-string|, except that single quotes
+			doe not need to be doubled.
+			If "eval" is specified, then any Vim expression in the
+			form {expr} is evaluated and the result replaces the
+			expression, like with |interp-string|.
 			Example where $HOME is expanded: >
 				let lines =<< trim eval END
 				  some text
-				  See the file `=$HOME`/.vimrc
+				  See the file {$HOME}/.vimrc
 				  more text
 				END
 <			There can be multiple Vim expressions in a single line
 			but an expression cannot span multiple lines.  If any
 			expression evaluation fails, then the assignment fails.
-			once the "`=" has been found {expr} and a backtick
-			must follow.  {expr} cannot be empty.
 
 			{endmarker} must not contain white space.
 			{endmarker} cannot start with a lower case character.
@@ -3318,10 +3327,10 @@ text...
 				DATA
 
 				let code =<< trim eval CODE
-				   let v = `=10 + 20`
-				   let h = "`=$HOME`"
-				   let s = "`=Str1()` abc `=Str2()`"
-				   let n = `=MyFunc(3, 4)`
+				   let v = {10 + 20}
+				   let h = "{$HOME}"
+				   let s = "{Str1()} abc {Str2()}"
+				   let n = {MyFunc(3, 4)}
 				CODE
 <
 								*E121*
@@ -3537,8 +3546,8 @@ text...
 :for {var} in {object}					*:for* *E690* *E732*
 :endfo[r]						*:endfo* *:endfor*
 			Repeat the commands between `:for` and `:endfor` for
-			each item in {object}.  {object} can be a |List| or
-			a |Blob|. *E1177*
+			each item in {object}.  {object} can be a |List|,
+			a |Blob| or a |String|. *E1177*
 
 			Variable {var} is set to the value of each item.
 			In |Vim9| script the loop variable must not have been