From 8ca01a93dc1e9139f7dc74036b3b40586b06ae15 Mon Sep 17 00:00:00 2001
From: Tom Ryder <tom@sanctum.geek.nz>
Date: Mon, 3 Jun 2019 22:24:37 +1200
Subject: Factor out Vim version checks into autoload func

---
 vim/autoload/vimrc.vim | 27 +++++++++++++++++++++++++++
 vim/vimrc              | 11 ++++-------
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/vim/autoload/vimrc.vim b/vim/autoload/vimrc.vim
index 71b29d61..bfbae263 100644
--- a/vim/autoload/vimrc.vim
+++ b/vim/autoload/vimrc.vim
@@ -45,3 +45,30 @@ function! vimrc#SplitEscaped(str, ...) abort
   return list
 
 endfunction
+
+" Convenience version function check that should work with 7.0 or newer;
+" takes strings like 7.3.251
+function! vimrc#Version(verstr) abort
+
+  " Throw toys if the string doesn't match the expected format
+  if a:verstr !~# '^\d\+\.\d\+.\d\+$'
+    echoerr 'Invalid version string: '.a:verstr
+  endif
+
+  " Split version string into major, minor, and patch level integers
+  let [major, minor, patch] = split(a:verstr, '\.')
+
+  " Create a string like 801 from a version number 8.1 to compare it to
+  " the v:version integer
+  let ver = major * 100 + minor
+
+  " Compare versions
+  if v:version > ver
+    return 1  " Current Vim is newer than the wanted one
+  elseif ver < v:version
+    return 0  " Current Vim is older than the wanted one
+  else
+    return has('patch'.patch)  " Versions equal, return patch presence
+  endif
+
+endfunction
diff --git a/vim/vimrc b/vim/vimrc
index ad582717..302f1388 100644
--- a/vim/vimrc
+++ b/vim/vimrc
@@ -14,9 +14,7 @@ set shiftwidth=4  " Indent with four spaces
 
 " Make insert mode tab key add the same number of spaces as 'shiftwidth', use
 " negative value to do this if Vim new enough to support it
-let &softtabstop = v:version > 703
-      \ || v:version == 703 && has('patch693')
-      \ ? -1 : &shiftwidth
+let &softtabstop = vimrc#Version('7.3.693') ? -1 : &shiftwidth
 
 " Allow me to backspace 'autoindent' spaces in insert mode, and back over the
 " end of lines I've inserted in this session
@@ -26,7 +24,7 @@ set backspace=indent,eol
 " full path in name, if Vim is new enough to support that
 set backup
 execute 'set backupdir^='.escape($MYVIM, '\ ').'/cache/backup'
-      \ . (has('patch-8.1.251') ? '//' : '')
+      \ . (vimrc#Version('8.1.251') ? '//' : '')
 
 " Add some *nix paths not to back up
 if has('unix')
@@ -74,13 +72,12 @@ set foldlevelstart=99
 set foldmethod=indent
 
 " Delete comment leaders when joining lines, if supported
-if v:version > 703
-      \ || v:version == 703 && has('patch541')
+if vimrc#Version('7.3.541')
   set formatoptions+=j
 endif
 
 " Don't break a single space after a period, if supported
-if has('patch-8.1.728')
+if vimrc#Version('8.1.728')
   set formatoptions+=p
 endif
 
-- 
cgit v1.2.3