Ocaml 检测JSON对象是否具有带有Yojson的密钥
如何在OCaml中使用Yojson检查JSON对象中是否存在字段?我需要类似于Ocaml 检测JSON对象是否具有带有Yojson的密钥,ocaml,Ocaml,如何在OCaml中使用Yojson检查JSON对象中是否存在字段?我需要类似于的东西,它具有如下功能: let () = let data = Yojson.Basic.from_string "{\"x\": 4}" in let has_x = has_key data "x" in let has_y = has_key data "y" in Printf.printf "has_x? %b, has_y? %b\n" has_x has_y (* true, false
的东西,它具有如下功能:
let () =
let data = Yojson.Basic.from_string "{\"x\": 4}" in
let has_x = has_key data "x" in
let has_y = has_key data "y" in
Printf.printf "has_x? %b, has_y? %b\n" has_x has_y (* true, false *)
Yojson.Basic.Util.member“x”数据
如果“x”不是Yojson数据的键,则返回Null
;如果“x”是键,则为“Assoc”
你可以定义
let has_key d k = not ((Yojson.Basic.Util.member k d) = `Null);;