Avoid uneacaped html entitites from doi api output

bibfmt/bin/bibfmt.ml

@@ -55,7 +55,7 @@ let bibfmt out strict single_line quiet verbose force files =
                     "Warning: No valid BibTeX entries found in the file.\n%!";
                   combined_content)
                 else
-                   let options =
+                  let options =
                     { Bibtex.default_options with strict; single_line }
                   in
                   Bibtex.pretty_print_bibtex ~options parse_result.items)
@@ -114,7 +114,8 @@ let () =
   in
   let single_line =
     let doc =
-      "Force field values onto a single line by replacing newlines with a space."
+      "Force field values onto a single line by replacing newlines with a \
+       space."
     in
     Arg.(value & flag & info [ "l"; "single-line" ] ~doc)
   in
@@ -141,7 +142,10 @@ let () =
     Arg.(value & pos_all string [] & info [] ~docv:"FILES" ~doc)
   in
   let bibfmt_t =
-    Term.(ret (const bibfmt $ out $ strict $ single_line $ quiet $ verbose $ force $ files))
+    Term.(
+      ret
+        (const bibfmt $ out $ strict $ single_line $ quiet $ verbose $ force
+       $ files))
   in
   let info =
     let doc = "A little CLI tool to pretty print bibtex files." in

bibfmt/lib/bibtex.ml

@@ -677,9 +677,8 @@ let format_entry options entry =
     |> List.filter (function
          | Field f -> (
              match f.value with
-             | QuotedStringValue s
-             | BracedStringValue s
-             | UnquotedStringValue s ->
+             | QuotedStringValue s | BracedStringValue s | UnquotedStringValue s
+               ->
                  String.length (String.trim s) > 0
              | NumberValue _ -> true)
          | EntryComment _ -> true)
@@ -706,7 +705,9 @@ let format_entry options entry =
   let contents_str =
     if filtered_contents = [] then ""
     else
-      let formatted_contents = List.map format_entry_content' filtered_contents in
+      let formatted_contents =
+        List.map format_entry_content' filtered_contents
+      in
       let rec add_commas_except_last = function
         | [] -> []
         | [ last ] -> [ last ] (* No comma for the last item *)

bibfmt/lib/bibtex.mli

@@ -150,12 +150,14 @@ val format_field_value_with_url_unescaping :
     @return String representation with URLs unescaped if applicable *)
 
 val format_field : bool -> bool -> field -> string
-(** [format_field capitalized single_line field] formats a complete field (name = value).
+(** [format_field capitalized single_line field] formats a complete field (name
+    = value).
     @param field The field to format
     @return String representation of the field *)
 
 val format_entry_content : bool -> bool -> entry_content -> string
-(** [format_entry_content capitalized single_line content] formats entry content (field or comment).
+(** [format_entry_content capitalized single_line content] formats entry content
+    (field or comment).
     @param content The entry content to format
     @return String representation of the content *)
 
@@ -201,13 +203,14 @@ val find_duplicate_groups :
     Each group contains at least 2 entries that match on the specified keys. *)
 
 val string_of_field_value : field_value -> string
-(** [string_of_field_value fv] converts a field value to its string representation.
+(** [string_of_field_value fv] converts a field value to its string
+    representation.
     @param fv The field value to convert
     @return String representation of the field value *)
 
 val make_field : string -> string -> entry_content
-(** [make_field name value] creates a BibTeX field with the given name and value.
-    The value is wrapped in braces.
+(** [make_field name value] creates a BibTeX field with the given name and
+    value. The value is wrapped in braces.
     @param name Field name
     @param value Field value as a string
     @return An entry_content Field with a BracedStringValue *)

doi2bib.opam

@@ -23,9 +23,8 @@ build: [
 dev-repo: "git+https://github.com/mseri/doi2bib.git"
 depends: [
   "dune" {>= "3.0"}
-  "ocaml" {>= "4.08"}
+  "ocaml" {>= "4.14.0"}
   "bibfmt" {= version}
-  "astring" {>= "0.8.0"}
   "cohttp-lwt-unix" {>= "2.5.0"}
   "cmdliner" {>= "1.1.0"}
   "clz" {>= "0.1.0"}

doi2bib.opam.template

@@ -1,8 +1,7 @@
 depends: [
-  "dune" {>= "2.8"}
-  "ocaml" {>= "4.08"}
+  "dune" {>= "3.0"}
+  "ocaml" {>= "4.14.0"}
   "bibfmt" {= version}
-  "astring" {>= "0.8.0"}
   "cohttp-lwt-unix" {>= "2.5.0"}
   "cmdliner" {>= "1.1.0"}
   "clz" {>= "0.1.0"}

doi2bib/bin/doi2bib.ml

@@ -6,7 +6,9 @@ let process_id outfile id =
   let open Lwt.Syntax in
   let* bibtex = Http.get_bib_entry @@ Parser.parse_id id in
 
-  let parsed_items = Bibtex.parse_bibtex bibtex in
+  let parsed_items =
+    Bibtex.parse_bibtex bibtex |> List.map Helpers.clean_item
+  in
   let formatted =
     if List.length parsed_items = 0 then (
       Printf.eprintf
@@ -88,7 +90,7 @@ let process_file outfile infile =
   let write_out () =
     let bibtex_out = Buffer.contents bibtex_buffer in
     let open Bibtex in
-    let parsed_items = parse_bibtex bibtex_out in
+    let parsed_items = parse_bibtex bibtex_out |> List.map Helpers.clean_item in
     let options = { default_options with strict = true } in
     let formatted = pretty_print_bibtex ~options parsed_items in
 

doi2bib/lib/doi2bib.ml

@@ -1,2 +1,3 @@
 module Http = Http
 module Parser = Parser
+module Helpers = Helpers

doi2bib/lib/dune

@@ -1,5 +1,5 @@
 (library
  (name doi2bib)
- (libraries astring cohttp-lwt-unix clz.cohttp ezxmlm lwt re unix)
+ (libraries cohttp-lwt-unix clz.cohttp ezxmlm lwt re unix bibfmt)
  (preprocess future_syntax)
  (package doi2bib))

doi2bib/lib/helpers.ml

@@ -0,0 +1,60 @@
+let decode_html_entities s =
+  let replacements =
+    [
+      ("&", "&");
+      (""", "\"");
+      ("'", "'");
+      ("©", "(c)");
+      ("®", "(r)");
+      ("™", "(tm)");
+      (" ", " ");
+    ]
+  in
+  List.fold_left
+    (fun acc (pattern, replacement) ->
+      let re = Re.compile (Re.str pattern) in
+      Re.replace_string ~all:true re ~by:replacement acc)
+    s replacements
+
+let escape_ampersand s =
+  (* We want to match '&' that is not preceded by '\', but the re library
+     does not support lookbehind, so we can match either the start of the string or a non-backslash character before '&', keep it and replace
+     the remaining '&' by '\&' *)
+  let re =
+    Re.compile
+      (Re.seq
+         [
+           Re.group (Re.alt [ Re.bos; Re.compl [ Re.char '\\' ] ]); Re.char '&';
+         ])
+  in
+  Re.replace re
+    ~f:(fun subs ->
+      let prefix = Re.Group.get subs 1 in
+      prefix ^ "\\&")
+    s
+
+(* The doi API can return html entities more or less everywhere in the fields
+   content, so we need to replace them. So far we replace some common ones
+   and make sure to escape the '&'. It can still fail if the entry includes #
+   or % (this is already treated in URLs), but I'd wait for it to happen
+   before taking any further action. *)
+let clean_string s = s |> decode_html_entities |> escape_ampersand
+
+let clean_field_value =
+  let open Bibtex in
+  function
+  | QuotedStringValue s -> QuotedStringValue (clean_string s)
+  | BracedStringValue s -> BracedStringValue (clean_string s)
+  | UnquotedStringValue s -> UnquotedStringValue (clean_string s)
+  | NumberValue n -> NumberValue n
+
+let clean_item =
+  let open Bibtex in
+  function
+  | Entry e ->
+      let clean_content = function
+        | Field f -> Field { f with value = clean_field_value f.value }
+        | EntryComment c -> EntryComment c
+      in
+      Entry { e with contents = List.map clean_content e.contents }
+  | Comment c -> Comment c

doi2bib/lib/parser.ml

@@ -8,18 +8,19 @@ let string_of_id = function
   | PubMed s -> "PubMed ID '" ^ s ^ "'"
 
 let parse_id id =
-  let open Astring in
-  let is_prefix affix s = String.is_prefix ~affix (String.Ascii.lowercase s) in
+  let is_prefix affix s =
+    let n = String.length affix in
+    String.length s >= n && String.sub (String.lowercase_ascii s) 0 n = affix
+  in
   let sub start s =
-    String.sub ~start s |> String.Sub.to_string |> String.trim
+    String.trim (String.sub s start (String.length s - start))
   in
-  let contains c s = String.exists (fun c' -> c' = c) s in
   match id with
   | doi when is_prefix "doi:" doi -> DOI (sub 4 doi)
   | arxiv when is_prefix "arxiv:" arxiv -> ArXiv (sub 6 arxiv)
   | pubmed when is_prefix "pmc" pubmed -> PubMed pubmed
-  | doi when contains '/' doi -> DOI (String.trim doi)
-  | arxiv when contains '.' arxiv -> ArXiv (String.trim arxiv)
+  | doi when String.contains doi '/' -> DOI (String.trim doi)
+  | arxiv when String.contains arxiv '.' -> ArXiv (String.trim arxiv)
   | _ -> raise (Parse_error id)
 
 let parse_atom id atom =
@@ -42,13 +43,17 @@ let parse_atom id atom =
       get_attr "term" a
     in
     let bibid =
-      let open Astring in
-      (match String.cuts ~empty:false ~sep:" " authors with
+      (match
+         String.split_on_char ' ' authors |> List.filter (fun s -> s <> "")
+       with
       | _ :: s :: _ -> s
       | s :: _ -> s
       | [] -> "")
       ^ year
-      ^ (String.cut ~sep:" " title |> Option.map fst |> Option.value ~default:"")
+      ^
+      match String.index_opt title ' ' with
+      | Some i -> String.sub title 0 i
+      | None -> ""
     in
     Printf.sprintf
       {|@misc{%s,

doi2bib/tests/doi.t/run.t

@@ -42,3 +42,18 @@ DOI entry containing parentheses
     YEAR      = {1989},
     PAGES     = {627-649}
   }
+DOI entry containing HTML entities and ampersands
+  $ doi2bib 10.2140/gt.2014.18.669
+  @article{Karshon_2014,
+    TITLE     = {Classification of Hamiltonian torus actions with two-dimensional quotients},
+    VOLUME    = {18},
+    ISSN      = {1465-3060},
+    URL       = {http://dx.doi.org/10.2140/gt.2014.18.669},
+    DOI       = {10.2140/gt.2014.18.669},
+    NUMBER    = {2},
+    JOURNAL   = {Geometry \& Topology},
+    PUBLISHER = {Mathematical Sciences Publishers},
+    AUTHOR    = {Karshon, Yael and Tolman, Susan},
+    YEAR      = {2014},
+    PAGES     = {669-716}
+  }

nix/default.nix

@@ -23,7 +23,6 @@ buildDunePackage ({
 
   propagatedBuildInputs = [
     bibfmt
-    astring
     cohttp-lwt-unix
     cmdliner
     clz