Split detect_indent.vim into autoload/plugin

Add load guard etc

1 files changed, 57 insertions, 0 deletions

diff --git a/vim/autoload/detect_indent.vim b/vim/autoload/detect_indent.vim
new file mode 100644
index 00000000..91952032
--- /dev/null
+++ b/vim/autoload/detect_indent.vim
@@ -0,0 +1,57 @@
+function s:CompareNumeric(a, b)
+  return a:a > a:b ? 1 : -1
+endfunction
+
+function detect_indent#() abort
+
+  let spaces = {
+        \ 'hist': {},
+        \ 'total': 0,
+        \}
+  let tabs = 0
+  let total = max([line('$'), 1024])
+
+  for lnum in range(1, total)
+    let line = getline(lnum)
+    let tabs += matchstr(line, '^\t*') != ''
+    let indent = strlen(matchstr(line, '^ *'))
+    if indent == 0
+      continue
+    endif
+    if !has_key(spaces['hist'], indent)
+      let spaces['hist'][indent] = 0
+    endif
+    let spaces['hist'][indent] += 1
+    let spaces['total'] += 1
+  endfor
+
+  if &expandtab == (spaces['total'] > tabs)
+    return
+  endif
+
+  if &expandtab
+    setlocal noexpandtab softtabstop=0
+    let &l:shiftwidth = &tabstop
+  else
+    setlocal expandtab
+    let shiftwidth = 0
+    let indents = keys(spaces['hist'])
+    call map(indents, 'str2nr(v:val)')
+    call sort(indents, 's:CompareNumeric')
+    for shiftwidth in indents
+      if spaces['hist'][shiftwidth] * 100 / spaces['total'] >= 5
+        break
+      endif
+    endfor
+    let &l:shiftwidth = shiftwidth
+    let &l:softtabstop = shiftwidth
+  endif
+
+  let undo_indent = 'setlocal expandtab? shiftwidth? softtabstop?'
+  if exists('b:undo_indent')
+    let b:undo_indent .= '|'.undo_indent
+  else
+    let b:undo_indent = undo_indent
+  endif
+
+endfunction