vim-patch:9.0.1704: Cannot use positional arguments for printf() (#24719)

Problem: Cannot use positional arguments for printf()
Solution: Support positional arguments in string formatting

closes: vim/vim#12140

0c6181fec4

Co-authored-by: Christ van Willegen <cvwillegen@gmail.com>

runtime/lua/vim/_meta/vimfn.lua

@@ -5989,7 +5989,11 @@ function vim.fn.prevnonblank(lnum) end
 --- The "%" starts a conversion specification.  The following
 --- arguments appear in sequence:
 ---
----   %  [flags]  [field-width]  [.precision]  type
+---   % [pos-argument] [flags] [field-width] [.precision] type
+---
+--- pos-argument
+---   At most one positional argument specifier. These
+---   take the form {n$}, where n is >= 1.
 ---
 --- flags
 ---   Zero or more of the following flags:
@@ -6058,6 +6062,13 @@ function vim.fn.prevnonblank(lnum) end
 --- <This limits the length of the text used from "line" to
 --- "width" bytes.
 ---
+--- If the argument to be formatted is specified using a posional
+--- argument specifier, and a '*' is used to indicate that a
+--- number argument is to be used to specify the width or
+--- precision, the argument(s) to be used must also be specified
+--- using a {n$} positional argument specifier. See |printf-$|.
+---
+---
 --- The conversion specifiers and their meanings are:
 ---
 ---     *printf-d* *printf-b* *printf-B* *printf-o* *printf-x* *printf-X*
@@ -6145,6 +6156,104 @@ function vim.fn.prevnonblank(lnum) end
 --- of "%" items.  If there are not sufficient or too many
 --- arguments an error is given.  Up to 18 arguments can be used.
 ---
+---           *printf-$*
+--- In certain languages, error and informative messages are
+--- more readable when the order of words is different from the
+--- corresponding message in English. To accomodate translations
+--- having a different word order, positional arguments may be
+--- used to indicate this. For instance: >vim
+---
+---   #, c-format
+---   msgid "%s returning %s"
+---   msgstr "waarde %2$s komt terug van %1$s"
+--- <
+--- In this example, the sentence has its 2 string arguments reversed
+--- in the output. >vim
+---
+---   echo printf(
+---     "In The Netherlands, vim's creator's name is: %1$s %2$s",
+---     "Bram", "Moolenaar")
+--- <  In The Netherlands, vim's creator's name is: Bram Moolenaar >vim
+---
+---   echo printf(
+---     "In Belgium, vim's creator's name is: %2$s %1$s",
+---     "Bram", "Moolenaar")
+--- <  In Belgium, vim's creator's name is: Moolenaar Bram
+---
+--- Width (and precision) can be specified using the '*' specifier.
+--- In this case, you must specify the field width position in the
+--- argument list. >vim
+---
+---   echo printf("%1$*2$.*3$d", 1, 2, 3)
+--- <  001 >vim
+---   echo printf("%2$*3$.*1$d", 1, 2, 3)
+--- <    2 >vim
+---   echo printf("%3$*1$.*2$d", 1, 2, 3)
+--- <  03 >vim
+---   echo printf("%1$*2$.*3$g", 1.4142, 2, 3)
+--- <  1.414
+---
+--- You can mix specifying the width and/or precision directly
+--- and via positional arguments: >vim
+---
+---   echo printf("%1$4.*2$f", 1.4142135, 6)
+--- <  1.414214 >vim
+---   echo printf("%1$*2$.4f", 1.4142135, 6)
+--- <  1.4142 >vim
+---   echo printf("%1$*2$.*3$f", 1.4142135, 6, 2)
+--- <    1.41
+---
+---           *E1400*
+--- You cannot mix positional and non-positional arguments: >vim
+---   echo printf("%s%1$s", "One", "Two")
+--- <  E1400: Cannot mix positional and non-positional
+---   arguments: %s%1$s
+---
+---           *E1401*
+--- You cannot skip a positional argument in a format string: >vim
+---   echo printf("%3$s%1$s", "One", "Two", "Three")
+--- <  E1401: format argument 2 unused in $-style
+---   format: %3$s%1$s
+---
+---           *E1402*
+--- You can re-use a [field-width] (or [precision]) argument: >vim
+---   echo printf("%1$d at width %2$d is: %01$*2$d", 1, 2)
+--- <  1 at width 2 is: 01
+---
+--- However, you can't use it as a different type: >vim
+---   echo printf("%1$d at width %2$ld is: %01$*2$d", 1, 2)
+--- <  E1402: Positional argument 2 used as field
+---   width reused as different type: long int/int
+---
+---           *E1403*
+--- When a positional argument is used, but not the correct number
+--- or arguments is given, an error is raised: >vim
+---   echo printf("%1$d at width %2$d is: %01$*2$.*3$d", 1, 2)
+--- <  E1403: Positional argument 3 out of bounds:
+---   %1$d at width %2$d is: %01$*2$.*3$d
+---
+--- Only the first error is reported: >vim
+---   echo printf("%01$*2$.*3$d %4$d", 1, 2)
+--- <  E1403: Positional argument 3 out of bounds:
+---   %01$*2$.*3$d %4$d
+---
+---           *E1404*
+--- A positional argument can be used more than once: >vim
+---   echo printf("%1$s %2$s %1$s", "One", "Two")
+--- <  One Two One
+---
+--- However, you can't use a different type the second time: >vim
+---   echo printf("%1$s %2$s %1$d", "One", "Two")
+--- <  E1404: Positional argument 1 type used
+---   inconsistently: int/string
+---
+---           *E1405*
+--- Various other errors that lead to a format string being
+--- wrongly formatted lead to: >vim
+---   echo printf("%1$d at width %2$d is: %01$*2$.3$d", 1, 2)
+--- <  E1405: Invalid format specifier:
+---   %1$d at width %2$d is: %01$*2$.3$d
+---
 --- @param fmt any
 --- @param expr1? any
 --- @return any