" File:         D2190.vim
" Created:      2017 Jun 30
" Last Change:  2018 May 15
" Version:      0.5
" Author:       Andy Wokula <anwoku@yahoo.de>
" License:      Vim License, see :h license
" Dependencies: (by :PutDepend)
"   CallOverloaded()

" HasPatchExpr({vimver}, {patchnr})
" HasPatchExpr({major}, {minor}, {patchnr})
" HasPatchExpr({patchlevel})
"
"   return an expression (string) that can be used (literally in a script)
"   to check the running Vim against a certain patch level.
"
"   Depending on the represented patch value, this for example returns
"	has("patch-7.4.237")
"   or
"	v:version > 704 || v:version == 704 && has("patch236")
"   (the patch numbers are different by intention).
"
"   The first variant is easier to read, but only understood since
"   Vim 7.4.237 (older Vims always return 0).  The second variant works
"   everywhere and will be used for versions up to Vim 7.4.236.
"
"   Arguments can be given in several ways:
"	{vimver}    (number) v:version, eg 704 for Vim 7.4
"	{patchnr}   (number) 0 or greater
"   or
"	{major}	    (number) major version, eg 7
"	{minor}	    (number) minor version, eg 4
"	{patchnr}   (number) 0 or greater
"   or
"	{patchlevel} (string) '7.4.237' or 'v7-4-237' or 'patch-7.4.237'
"
"   A general check can use the newer notation for a newer patch, but must
"   use the older notation for an older patch.
"

" History:
" 2019 Jun 14	Note: v:versionlong (added with 8.1.1526) cannot be used for
"		version checking
" 2018 Jul 28	BF: HasPatchExpr('701', '040') => '... has("patch36")'
" 2018 May 15	not sure why Empty() was used
" 2017 Nov 05	BF: HasPatchExpr('7.1.040') => '... has("patch36")'
" 2017 Nov 03	use CallOverloaded()
" 2017 Jul 17	BF: checked argument against version of running Vim (stupid)

func! HasPatchExpr(arg, ...) "{{{
    return CallOverloaded(s:f, [a:arg] + a:000, {})
endfunc "}}}


let s:f = {}

func! s:f.XX(vimver, patchnr) "{{{
    return s:HasPatchExpr(str2nr(a:vimver), str2nr(a:patchnr))
endfunc "}}}

func! s:f.XXX(major, minor, patchnr) "{{{
    return s:HasPatchExpr(str2nr(a:major) * 100 + str2nr(a:minor), str2nr(a:patchnr))
endfunc "}}}

func! s:f.S(str) "{{{
    " from HasPatch()
    let ml = matchlist(a:str, '\(\d\+\)\D\(\d\+\)\D\(\d\+\)')
    if !empty(ml)
	let [major, minor, patchnr] = ml[1:3]
	return s:HasPatchExpr(str2nr(major) * 100 + str2nr(minor), str2nr(patchnr))
    else
	echoerr printf('HasPatchExpr(): invalid argument "%s"', a:str)
	return ''
    endif
endfunc "}}}

func! s:f._(...) "{{{
    echoerr 'HasPatchExpr(): unrecognized arguments'
    return ''
endfunc "}}}


func! s:HasPatchExpr(vimver, patchnr) "{{{
    if a:patchnr >= 1
	if a:vimver > 704 || a:vimver == 704 && a:patchnr >= 237
	    return printf('has("patch-%d.%d.%d")', a:vimver/100, a:vimver%100, a:patchnr)
	else
	    return printf('v:version > %d || v:version == %d && has("patch%d")', a:vimver, a:vimver, a:patchnr)
	endif
    else
	return printf('v:version >= %d', a:vimver)
    endif
endfunc "}}}