1 files changed, 41 insertions, 0 deletions
diff --git a/runtime/indent/treetop.vim b/runtime/indent/treetop.vim
new file mode 100644
index 0000000..6c39c69
--- /dev/null
+++ b/runtime/indent/treetop.vim
@@ -0,0 +1,41 @@
+" Vim indent file
+" Language:		Treetop
+" Maintainer:		Doug Kearns <dougkearns@gmail.com>
+" Previous Maintainer:	Nikolai Weibull <now@bitwi.se>
+" Last Change:		2022 April 25
+
+if exists("b:did_indent")
+  finish
+endif
+let b:did_indent = 1
+
+setlocal indentexpr=GetTreetopIndent()
+setlocal indentkeys=0{,0},!^F,o,O,=end
+setlocal nosmartindent
+
+let b:undo_indent = "setl inde< indk< si<"
+
+if exists("*GetTreetopIndent")
+  finish
+endif
+
+function GetTreetopIndent()
+  let pnum = prevnonblank(v:lnum - 1)
+  if pnum == 0
+    return 0
+  endif
+
+  let ind = indent(pnum)
+  let line = getline(pnum)
+
+  if line =~ '^\s*\%(grammar\|module\|rule\)\>'
+    let ind += shiftwidth()
+  endif
+
+  let line = getline(v:lnum)
+  if line =~ '^\s*end\>'
+    let ind -= shiftwidth()
+  end
+
+  return ind
+endfunction