some progress

ocp_indent.ml

@@ -0,0 +1,14 @@
+let _ = Approx_lexer.enable_extension "lwt"
+
+let indent s in_lines =
+  let output =
+    { IndentPrinter.debug = false
+    ; config = IndentConfig.default
+    ; in_lines
+    ; indent_empty = true
+    ; adaptive = true
+    ; kind = IndentPrinter.Print (fun s acc -> acc ^ s)
+    }
+  in
+  let stream = Nstream.of_string s in
+  IndentPrinter.proceed output stream IndentBlock.empty ""