vim-patch:8.2.{1536,1540}: charclass() (#19748)

vim-patch:8.2.1536: cannot get the class of a character; emoji widths are wrong

Problem:    Cannot get the class of a character; emoji widths are wrong in
            some environments.
Solution:   Add charclass(). Update some emoji widths.  Add script to check
            emoji widths.
https://github.com/vim/vim/commit/4e4473c927167fd24e5c8df90e0e8035080cf2da

Use latest charclass() docs from Vim.
Rewrite DoIt() in emoji_list.vim in Lua.
Omit emoji table updates:
- emoji_width update looks wrong as these added ranges are only double-width when followed by 0xFE0F.
- Other updates are too old.

vim-patch:8.2.1540: the user cannot try out emoji character widths

Problem:    The user cannot try out emoji character widths.
Solution:   Move the emoji script to the runtime/tools directory.
https://github.com/vim/vim/commit/98945560c1ae6e2ddee820a7de718a36e3f4b6e5

3 files changed, 36 insertions, 1 deletions

diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index d0b28ce875..719953bc22 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -77,6 +77,7 @@ changenr()			Number	current change number
 chanclose({id} [, {stream}])	Number	Closes a channel or one of its streams
 chansend({id}, {data})		Number	Writes {data} to channel
 char2nr({expr} [, {utf8}])	Number	ASCII/UTF-8 value of first char in {expr}
+charclass({string})		Number	character class of {string}
 charcol({expr})			Number	column number of cursor or mark
 charidx({string}, {idx} [, {countcc}])
 				Number	char index of byte {idx} in {string}
@@ -1064,7 +1065,19 @@ char2nr({string} [, {utf8}])					*char2nr()*
 
 		Can also be used as a |method|: >
 			GetChar()->char2nr()
-<
+
+charclass({string})					*charclass()*
+		Return the character class of the first character in {string}.
+		The character class is one of:
+			0	blank
+			1	punctuation
+			2	word character
+			3	emoji
+			other	specific Unicode class
+		The class is used in patterns and word motions.
+		Returns 0 if {string} is not a |String|.
+
+
 							*charcol()*
 charcol({expr})	Same as |col()| but returns the character index of the column
 		position given with {expr} instead of the byte position.
diff --git a/runtime/doc/usr_41.txt b/runtime/doc/usr_41.txt
index 235925c033..0c907bfb68 100644
--- a/runtime/doc/usr_41.txt
+++ b/runtime/doc/usr_41.txt
@@ -606,6 +606,7 @@ String manipulation:					*string-functions*
 	strtrans()		translate a string to make it printable
 	tolower()		turn a string to lowercase
 	toupper()		turn a string to uppercase
+	charclass()		class of a character
 	match()			position where a pattern matches in a string
 	matchend()		position where a pattern match ends in a string
 	matchfuzzy()		fuzzy matches a string in a list of strings
diff --git a/runtime/tools/emoji_list.vim b/runtime/tools/emoji_list.vim
new file mode 100644
index 0000000000..c335b8c88f
--- /dev/null
+++ b/runtime/tools/emoji_list.vim
@@ -0,0 +1,21 @@
+" Script to fill the window with emoji characters, one per line.
+" Source this script: :source %
+
+if &modified
+  new
+else
+  enew
+endif
+
+lua << EOF
+  local lnum = 1
+  for c = 0x100, 0x1ffff do
+    local cs = vim.fn.nr2char(c)
+    if vim.fn.charclass(cs) == 3 then
+      vim.fn.setline(lnum, '|' .. cs .. '| ' .. vim.fn.strwidth(cs))
+      lnum = lnum + 1
+    end
+  end
+EOF
+
+set nomodified