Simplified RSS2 decoder in OCaml using the Ezxmlm library

rss2.ml

type item = {
  title : string;
  categories : string list;
  link : string;
  description : string;
  pub_date : string;
}

type channel = {
  title : string;
  link : string;
  description : string;
  items : item list;
}

type rss2 = { channels : channel list }

open Ezxmlm

let ( .?[] ) nodes tag = member tag nodes
let ( .??[] ) nodes tag = members tag nodes

let data = function [`Data d] -> d | _ -> assert false

let item xml = {
  title = data xml.?["title"];
  categories = List.map data xml.??["category"];
  link = data xml.?["link"];
  description = data xml.?["description"];
  pub_date = data xml.?["pubDate"];
}

let channel xml = {
  title = data xml.?["title"];
  link = data xml.?["link"];
  description = data xml.?["description"];
  items = List.map item xml.??["item"];
}

let rss2 xml = { channels = List.map channel xml.?["rss"].??["channel"] }