locale is.

Examples:
	123.456
	+0.0001
	55.0
	-0.123
	1.234e03
	1.0E-6
	-3.1416e+88

These are INVALID:
	3.		empty {M}
	1e40		missing .{M}

Rationale:
Before floating point was introduced, the text "123.456" was interpreted as
the two numbers "123" and "456", both converted to a string and concatenated,
resulting in the string "123456".  Since this was considered pointless, and we
could not find it intentionally being used in Vim scripts, this backwards
incompatibility was accepted in favor of being able to use the normal notation
for floating point numbers.

							*float-pi* *float-e*
A few useful values to copy&paste: >
	:let pi = 3.14159265359
	:let e  = 2.71828182846
Or, if you don't want to write them in as floating-point literals, you can
also use functions, like the following: >
	:let pi = acos(-1.0)
	:let e  = exp(1.0)
<
						*floating-point-precision*
The precision and range of floating points numbers depends on what "double"
means in the library Vim was compiled with.  There is no way to change this at
runtime.

The default for displaying a |Float| is to use 6 decimal places, like using
printf("%g", f).  You can select something else when using the |printf()|
function.  Example: >
	:echo printf('%.15e', atan(1))
<	7.853981633974483e-01


------------------------------------------------------------------------------
string					*string* *String* *expr-string* *E114*

"string"		string constant		*expr-quote*

Note that double quotes are used.

A string constant accepts these special characters:
\...	three-digit octal number (e.g., "\316")
\..	two-digit octal number (must be followed by non-digit)
\.	one-digit octal number (must be followed by non-digit)
\x..	byte specified with two hex numbers (e.g., "\x1f")
\x.	byte specified with one hex number (must be followed by non-hex char)
\X..	same as \x..
\X.	same as \x.
\u....	character specified with up to 4 hex numbers, stored as UTF-8
	(e.g., "\u02a4")
\U....	same as \u but allows up to 8 hex numbers.
\b	backspace <BS>
\e	escape <Esc>
\f	formfeed 0x0C
\n	newline <NL>
\r	return <CR>
\t	tab <Tab>
\\	backslash
\"	double quote
\<xxx>	Special key named "xxx".  e.g. "\<C-W>" for CTRL-W.  This is for use
	in mappings, the 0x80 byte is escaped.
	To use the double quote character it must be escaped: "<M-\">".
	Don't use <Char-xxxx> to get a UTF-8 character, use \uxxxx as
	mentioned above.
\<*xxx>	Like \<xxx> but prepends a modifier instead of including it in the
	character.  E.g. "\<C-w>" is one character 0x17 while "\<*C-w>" is four
	bytes: 3 for the CTRL modifier and then character "W".

Note that "\xff" is stored as the byte 255, which may be invalid in some
encodings.  Use "\u00ff" to store character 255 correctly as UTF-8.

Note that "\000" and "\x00" force the end of the string.


------------------------------------------------------------------------------
blob-literal				*blob-literal* *E973*

Hexadecimal starting with 0z or 0Z, with an arbitrary number of bytes.
The sequence must be an even number of hex characters.  Example: >
	:let b = 0zFF00ED015DAF


------------------------------------------------------------------------------
literal-string						*literal-string* *E115*

'string'		string constant			*expr-'*

Note that single quotes are used.

This string is taken as it is.  No backslashes are removed or have a special
meaning.  The only exception is that two quotes stand for one quote.

Single quoted strings are useful for patterns, so that backslashes do not need
to be doubled.  These two commands are equivalent: >
	if a =~ "\\s*"
	if a =~ '\s*'


------------------------------------------------------------------------------
interpolated-string				*$quote* *interpolated-string*

$"string"		interpolated string constant		*expr-$quote*
$'string'		interpolated literal string constant	*expr-$'*

Interpolated strings are an extension of the |string| and |literal-string|,
allowing the inclusion of Vim script expressions (see |expr1|).  Any
expression returning a value can