diff --git a/cpdf.ml b/cpdf.ml
index cbd2e9e..bf990ff 100644
--- a/cpdf.ml
+++ b/cpdf.ml
@@ -1241,7 +1241,7 @@ let output_string_of_target pdf fastrefnums x =
 let list_bookmarks encoding range pdf output =
   let process_stripped escaped =
     let b = Buffer.create 200 in
-      List.iter
+      iter
         (fun x ->
            if x <= 127 then Buffer.add_char b (char_of_int x))
         escaped;
@@ -1371,7 +1371,7 @@ let output_page_info pdf range =
     and rotation page =
       Pdfpage.int_of_rotation page.Pdfpage.rotate
     in
-      List.iter
+      iter
         (fun pnum ->
            let page = select pnum pages in
              Printf.printf "Page %i:\n" pnum;
@@ -1687,8 +1687,8 @@ let remove_slash s =
   | _ -> raise (Failure "remove_slash")
 
 let extract_widths chars_and_widths =
-  let win_to_name = List.map (fun (x, y) -> (y, x)) Pdfglyphlist.name_to_win in
-    List.map
+  let win_to_name = map (fun (x, y) -> (y, x)) Pdfglyphlist.name_to_win in
+    map
       (fun x ->
           try
             let name = List.assoc x win_to_name in
@@ -2079,10 +2079,10 @@ let rec insert_after_many_changes isbefore padsize offset range = function
         item::insert_after_many_changes isbefore padsize offset range t
 
 let print_changes =
-  List.iter (fun (f, t) -> Printf.printf "%i --> %i\n" f t)
+  iter (fun (f, t) -> Printf.printf "%i --> %i\n" f t)
 
 let pad_with_pdf (range : int list) (pdf : Pdf.t) (isbefore : bool) (padfile : Pdf.t) =
-  let range = List.sort compare (setify range) in
+  let range = sort compare (setify range) in
   let merged =
     Pdfmerge.merge_pdfs
       false false ["a"; "b"] [pdf; padfile] [ilist 1 (Pdfpage.endpage pdf); ilist 1 (Pdfpage.endpage padfile)]
@@ -2091,7 +2091,7 @@ let pad_with_pdf (range : int list) (pdf : Pdf.t) (isbefore : bool) (padfile : P
     cleave (Pdfpage.pages_of_pagetree merged) (Pdfpage.endpage pdf) 
   in
     let newpages =
-      List.map
+      map
         (fun (pagenum, page) ->
            if mem pagenum range then
              (if isbefore then padpages @ [page] else [page] @ padpages)
@@ -2121,7 +2121,7 @@ let pad padwith range pdf isbefore =
           let pages' = insert_after_many pages (combine range blankpages) in
           let changes =
             insert_after_many_changes
-              isbefore 1 0 (List.map (fun x -> x + i) range) (ilist 1 (length pages))
+              isbefore 1 0 (map (fun x -> x + i) range) (ilist 1 (length pages))
           in
             Pdfpage.change_pages ~changes true pdf pages'
 
@@ -2287,7 +2287,7 @@ let transform_annotations pdf transform rest =
   match Pdf.lookup_direct pdf "/Annots" rest with
   | Some (Pdf.Array annots) ->
       (* Always indirect references, so alter in place *)
-      List.iter
+      iter
         (function
          | Pdf.Indirect i ->
              (*Printf.printf "Found an annotation to modify...\n";*)
@@ -2524,12 +2524,12 @@ let stamp relative_to_cropbox position topline midline fast scale_to_fit isover
                 in
                   let changed =
                     let changes =
-                      List.map (fun x -> (x, x)) (ilist 1 (length new_pages))
+                      map (fun x -> (x, x)) (ilist 1 (length new_pages))
                     in
                       Pdfpage.change_pages ~changes true merged new_pages
                   in
                     let new_refnumbers = Pdf.page_reference_numbers changed in
-                    let changetable = hashtable_of_dictionary (List.combine marks_refnumbers new_refnumbers) in
+                    let changetable = hashtable_of_dictionary (combine marks_refnumbers new_refnumbers) in
                     let new_marks = map (change_bookmark changetable) marks in
                       Pdfmarks.add_bookmarks new_marks changed
 
@@ -2542,14 +2542,14 @@ let equalize_pages under over =
   let length_over = Pdfpage.endpage over in
     if length_over > length_under then
       let changes =
-        List.map (fun x -> (x, x)) (ilist 1 length_under)
+        map (fun x -> (x, x)) (ilist 1 length_under)
       in
         (under,
          (Pdfpage.change_pages
             ~changes true over (take (Pdfpage.pages_of_pagetree over) length_under)))
     else if length_under > length_over then
       let changes =
-        List.map (fun x -> (x, x)) (ilist 1 length_over)
+        map (fun x -> (x, x)) (ilist 1 length_over)
       in
         (under,
          Pdfpage.change_pages
@@ -2591,7 +2591,7 @@ let combine_pages fast under over scaletofit swap equalize =
           in
             (* Build the changes. 123456 -> 123123 *)
             let changes =
-              let len = List.length new_pages in
+              let len = length new_pages in
                 combine (ilist 1 (len * 2)) (let x = ilist 1 len in x @ x)
             in
               let changed = Pdfpage.change_pages ~changes true merged new_pages in
@@ -3058,7 +3058,7 @@ let rec renumber_in_dest table indest = function
       Pdf.recurse_array (renumber_in_dest table indest) a
   | Pdf.Dictionary d ->
       Pdf.Dictionary
-        (List.map
+        (map
           (function
              ("/Dest", v) -> ("/Dest", renumber_in_dest table true v)
            | (k, v) -> (k, renumber_in_dest table indest v))
@@ -3078,7 +3078,7 @@ let copy_annotations_page topdf frompdf frompage topage =
              (Pdf.page_reference_numbers frompdf)
              (Pdf.page_reference_numbers topdf))
       in
-        List.iter
+        iter
          (function
             (* FIXME: We assume they are indirects. Must also do direct, though rare.*)
             Pdf.Indirect x ->
@@ -3221,7 +3221,7 @@ let twoup_pages_inner isstack fast pdf = function
        (* Change the pattern matrices before combining resources *)
        let pages, h =
          let r =
-           List.map2
+           map2
              (fun p t -> change_pattern_matrices_page pdf t p)
              pages transforms
          in
@@ -3248,7 +3248,7 @@ let twoup_pages_inner isstack fast pdf = function
                 [Pdfops.stream_of_ops
                   ([Pdfops.Op_q] @ [Pdfops.Op_cm transform] @ clipops @ ops @ [Pdfops.Op_Q])]
           in
-            List.flatten
+            flatten
               (map2
               (fun p t ->
                  transform_annotations pdf t p.Pdfpage.rest;
@@ -3281,7 +3281,7 @@ let f_twoup f_pages pdf =
       let pagesets = splitinto 2 pages in
         let renumbered = map (Pdfpage.renumber_pages pdf) pagesets in
           let pages' = map (f_pages pdf) renumbered in
-            let changes = List.map (fun x -> (x, (x + 1) / 2)) pagenums in
+            let changes = map (fun x -> (x, (x + 1) / 2)) pagenums in
               (*print_changes changes;*)
               Pdfpage.change_pages ~changes true pdf pages'
 
@@ -3477,7 +3477,7 @@ let get_xmp_info pdf name =
   | Some metadata ->
       try
         let _, tree = xmltree_of_bytes metadata in
-          let results = List.map (fun (kind, key) -> match get_data_for kind key tree with Some x -> x | None -> "") tocheck in
+          let results = map (fun (kind, key) -> match get_data_for kind key tree with Some x -> x | None -> "") tocheck in
             match lose (eq "") results with
              x::_ -> x
            | [] -> ""
@@ -3489,7 +3489,7 @@ let rec set_xml_field kind fieldname value = function
   D data -> D data
 | E (((n, n'), m), _ (*[D _]*)) when n = kind && n' = fieldname -> (* Replace anything inside, including nothing i.e <tag/> *)
     E (((n, n'), m), [D value])
-| E (x, ts) -> E (x, List.map (set_xml_field kind fieldname value) ts)
+| E (x, ts) -> E (x, map (set_xml_field kind fieldname value) ts)
 
 let set_pdf_info_xml kind fieldname value xmldata pdf =
   let dtd, tree = xmltree_of_bytes xmldata in
@@ -3505,7 +3505,7 @@ let set_pdf_info_xml kind fieldname value xmldata pdf =
 
 let set_pdf_info_xml_many changes value xmldata pdf =
   let xmldata = ref xmldata in
-    List.iter
+    iter
       (fun (kind, fieldname) ->
          xmldata := set_pdf_info_xml kind fieldname value !xmldata pdf)
       changes;
@@ -3688,7 +3688,7 @@ let replacements pdf =
 
 let create_metadata pdf =
   let xmp = ref xmp_template in
-  List.iter
+  iter
     (fun (s, r) -> xmp := string_replace_all s r !xmp)
     (replacements pdf);
   set_metadata_from_bytes false (bytes_of_string !xmp) pdf
@@ -4301,7 +4301,7 @@ let ocg_list pdf =
   | Some ocpdict ->
       match Pdf.lookup_direct pdf "/OCGs" ocpdict with
         Some (Pdf.Array elts) ->
-          List.iter
+          iter
             (function
                Pdf.Indirect i ->
                  (match Pdf.lookup_direct pdf "/Name" (Pdf.lookup_obj pdf i) with
diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index 41a10f2..d37e534 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -11,7 +11,7 @@ open Pdfio
 let tempfiles = ref []
 
 let exit n =
-  begin try List.iter Sys.remove !tempfiles with _ -> exit n end;
+  begin try iter Sys.remove !tempfiles with _ -> exit n end;
   exit n
 
 let initial_file_size = ref 0
@@ -3450,7 +3450,7 @@ let add_bookmark_title filename use_title pdf =
 let bookmarks_open_to_level n pdf =
   let marks = Pdfmarks.read_bookmarks pdf in
   let newmarks =
-    List.map
+    map
       (fun m -> {m with Pdfmarks.isopen = m.Pdfmarks.level < n})
       marks
   in
@@ -3651,9 +3651,9 @@ let go () =
                     else
                       let pdfs =
                         if args.merge_add_bookmarks then
-                          List.map2
+                          map2
                             (fun filename pdf -> add_bookmark_title filename args.merge_add_bookmarks_use_titles pdf)
-                            (List.map (function InFile s -> s | StdIn -> "" | AlreadyInMemory _ -> "") names)
+                            (map (function InFile s -> s | StdIn -> "" | AlreadyInMemory _ -> "") names)
                             pdfs
                         else
                           pdfs
diff --git a/cpdfwriteJSON.ml b/cpdfwriteJSON.ml
index 816e733..362ed62 100644
--- a/cpdfwriteJSON.ml
+++ b/cpdfwriteJSON.ml
@@ -1,3 +1,5 @@
+open Pdfutil
+
 module J = Tjjson
 module P = Pdf
 module O = Pdfops
@@ -14,15 +16,15 @@ let rec json_of_object pdf fcs no_stream_data = function
   | P.Real r -> J.Number (sof r)
   | P.String s -> J.String s
   | P.Name n -> J.String n
-  | P.Array objs -> J.Array (List.map (json_of_object pdf fcs no_stream_data) objs)
+  | P.Array objs -> J.Array (map (json_of_object pdf fcs no_stream_data) objs)
   | P.Dictionary elts ->
-      List.iter
+      iter
         (function
             ("/Contents", P.Indirect i) -> fcs i
-          | ("/Contents", P.Array elts) -> List.iter (function P.Indirect i -> fcs i | _ -> ()) elts
+          | ("/Contents", P.Array elts) -> iter (function P.Indirect i -> fcs i | _ -> ()) elts
           | _ -> ())
         elts;
-      J.Object (List.map (fun (k, v) -> (k, json_of_object pdf fcs no_stream_data v)) elts)
+      J.Object (map (fun (k, v) -> (k, json_of_object pdf fcs no_stream_data v)) elts)
   | P.Stream ({contents = (Pdf.Dictionary dict as d, stream)} as mut) as thestream ->
       Pdf.getstream thestream;
       let str =
@@ -80,7 +82,7 @@ let json_of_op pdf no_stream_data = function
   | O.Op_gs s -> J.Array [J.String s; J.String "gs"]
   | O.Op_Do s -> J.Array [J.String s; J.String "Do"]
   | O.Op_CS s -> J.Array [J.String s; J.String "CS"]
-  | O.Op_SCN fs -> J.Array ((List.map (fun x -> J.Number (sof x)) fs) @ [J.String "SCN"])
+  | O.Op_SCN fs -> J.Array ((map (fun x -> J.Number (sof x)) fs) @ [J.String "SCN"])
   | O.Op_j j -> J.Array [J.Number (soi j); J.String "j"] 
   | O.Op_cm t ->
       J.Array
@@ -92,7 +94,7 @@ let json_of_op pdf no_stream_data = function
          J.Number (sof t.Pdftransform.f);
          J.String "cm"]
   | O.Op_d (fl, y) ->
-      J.Array [J.Array (List.map (fun x -> J.Number (sof x)) fl); J.Number (sof y); J.String "d"]
+      J.Array [J.Array (map (fun x -> J.Number (sof x)) fl); J.Number (sof y); J.String "d"]
   | O.Op_w w -> J.Array [J.Number (sof w); J.String "w"]
   | O.Op_J j -> J.Array [J.Number (soi j); J.String "J"]
   | O.Op_M m -> J.Array [J.Number (sof m); J.String "M"]
@@ -138,9 +140,9 @@ let json_of_op pdf no_stream_data = function
         [J.Number (sof a); J.Number (sof b); J.Number (sof c);
          J.Number (sof d); J.Number (sof e); J.Number (sof k); J.String "d1"]
   | O.Op_cs s -> J.Array [J.String s; J.String "cs"]
-  | O.Op_SC fs -> J.Array (List.map (fun x -> J.Number (sof x)) fs @ [J.String "SC"])
-  | O.Op_sc fs -> J.Array (List.map (fun x -> J.Number (sof x)) fs @ [J.String "sc"])
-  | O.Op_scn fs -> J.Array (List.map (fun x -> J.Number (sof x)) fs @ [J.String "scn"])
+  | O.Op_SC fs -> J.Array (map (fun x -> J.Number (sof x)) fs @ [J.String "SC"])
+  | O.Op_sc fs -> J.Array (map (fun x -> J.Number (sof x)) fs @ [J.String "sc"])
+  | O.Op_scn fs -> J.Array (map (fun x -> J.Number (sof x)) fs @ [J.String "scn"])
   | O.Op_G k -> J.Array [J.Number (sof k); J.String "G"]
   | O.Op_g k -> J.Array [J.Number (sof k); J.String "g"]
   | O.Op_RG (r, g, b) -> J.Array [J.Number (sof r); J.Number (sof g); J.Number (sof b); J.String "RG"]
@@ -151,9 +153,9 @@ let json_of_op pdf no_stream_data = function
   | O.Op_BMC s -> J.Array [J.String s; J.String "BMC"]
   | O.Op_Unknown _ -> J.Array [J.String "Unknown"]
   | O.Op_SCNName (s, fs) ->
-      J.Array (List.map (fun x -> J.Number (sof x)) fs @ [J.String s; J.String "SCNName"])
+      J.Array (map (fun x -> J.Number (sof x)) fs @ [J.String s; J.String "SCNName"])
   | O.Op_scnName (s, fs) ->
-      J.Array (List.map (fun x -> J.Number (sof x)) fs @ [J.String s; J.String "scnName"])
+      J.Array (map (fun x -> J.Number (sof x)) fs @ [J.String s; J.String "scnName"])
   | O.InlineImage (dict, data) -> J.Array [json_of_object pdf (fun _ -> ()) no_stream_data dict; J.String (Pdfio.string_of_bytes data)]
   | O.Op_DP (s, obj) -> J.Array [J.String s; json_of_object pdf (fun _ -> ()) no_stream_data obj; J.String "DP"]
 
@@ -163,7 +165,7 @@ let json_of_op pdf no_stream_data = function
 * PDF standard. *)
 let parse_content_stream pdf resources bs =
   let ops = Pdfops.parse_stream pdf resources [bs] in
-    J.Array (List.map (json_of_op pdf false) ops)
+    J.Array (map (json_of_op pdf false) ops)
 
 let json_of_pdf parse_content no_stream_data pdf =
   let trailerdict = (0, json_of_object pdf (fun x -> ()) no_stream_data pdf.Pdf.trailerdict) in
@@ -178,12 +180,12 @@ let json_of_pdf parse_content no_stream_data pdf =
       trailerdict::!ps
   in
     if parse_content then
-      List.iter (fun n -> Pdfcodec.decode_pdfstream_until_unknown pdf (Pdf.lookup_obj pdf n)) !content_streams;
+      iter (fun n -> Pdfcodec.decode_pdfstream_until_unknown pdf (Pdf.lookup_obj pdf n)) !content_streams;
     let pairs_parsed =
       if not parse_content then pairs else
-        List.map
+        map
           (fun (objnum, obj) ->
-             if Pdfutil.mem objnum !content_streams then
+             if mem objnum !content_streams then
                begin match obj with
                | J.Array [dict; J.String _] ->
                    (* FIXME Proper resources here for reasons explained above *)
@@ -200,7 +202,7 @@ let json_of_pdf parse_content no_stream_data pdf =
           pairs
     in
       J.Array
-        (List.map
+        (map
           (fun (objnum, jsonobj) -> J.Array [J.Number (soi objnum); jsonobj])
           pairs_parsed)