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detect if JSON object has key with Yojson
2019 Community Moderator ElectionIn Functional Programming, what is a functor?transition function of a automatonHow to access a list in OCamlWhy does ocaml need both “let” and “let rec”?Difference between = and == and comparison of nansHow to make an OCaml definition for a given syntax definition?What's the reason of 'let rec' for impure functional language OCaml?OCaml : How to create a list of n 1's inHow to update JSON object using Yojson?OCaml zip elements of an array 2 by 2
How can I check if a field exists in a JSON object using Yojson in OCaml? I need something like a has_key function like the following:
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? %bn" has_x has_y (* true, false *)
ocaml
asked Mar 7 at 17:31
Mei ZhangMei Zhang
350110
add a comment |
How can I check if a field exists in a JSON object using Yojson in OCaml? I need something like a has_key function like the following:
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? %bn" has_x has_y (* true, false *)
ocaml
asked Mar 7 at 17:31
Mei ZhangMei Zhang
350110
add a comment |
How can I check if a field exists in a JSON object using Yojson in OCaml? I need something like a has_key function like the following:
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? %bn" has_x has_y (* true, false *)
ocaml
asked Mar 7 at 17:31
Mei ZhangMei Zhang
350110
How can I check if a field exists in a JSON object using Yojson in OCaml? I need something like a has_key function like the following:
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? %bn" has_x has_y (* true, false *)
ocaml
ocaml
asked Mar 7 at 17:31
Mei ZhangMei Zhang
350110
asked Mar 7 at 17:31
Mei ZhangMei Zhang
350110
asked Mar 7 at 17:31
Mei ZhangMei Zhang
350110
asked Mar 7 at 17:31
Mei ZhangMei Zhang
350110
asked Mar 7 at 17:31
Mei ZhangMei Zhang
350110
350110
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
Yojson.Basic.Util.member "x" data returns Null if "x" is not a key of the Yojson data; or a `Assoc if "x" is a key.
you can define
let has_key d k = not ((Yojson.Basic.Util.member k d) = `Null);;
answered Mar 7 at 18:45
Pierre G.Pierre G.
3,4231723
add a comment |
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1 Answer
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Yojson.Basic.Util.member "x" data returns Null if "x" is not a key of the Yojson data; or a `Assoc if "x" is a key.
you can define
let has_key d k = not ((Yojson.Basic.Util.member k d) = `Null);;
answered Mar 7 at 18:45
Pierre G.Pierre G.
3,4231723
add a comment |
Yojson.Basic.Util.member "x" data returns Null if "x" is not a key of the Yojson data; or a `Assoc if "x" is a key.
you can define
let has_key d k = not ((Yojson.Basic.Util.member k d) = `Null);;
answered Mar 7 at 18:45
Pierre G.Pierre G.
3,4231723
add a comment |
Yojson.Basic.Util.member "x" data returns Null if "x" is not a key of the Yojson data; or a `Assoc if "x" is a key.
you can define
let has_key d k = not ((Yojson.Basic.Util.member k d) = `Null);;
answered Mar 7 at 18:45
Pierre G.Pierre G.
3,4231723
Yojson.Basic.Util.member "x" data returns Null if "x" is not a key of the Yojson data; or a `Assoc if "x" is a key.
you can define
let has_key d k = not ((Yojson.Basic.Util.member k d) = `Null);;
answered Mar 7 at 18:45
Pierre G.Pierre G.
3,4231723
answered Mar 7 at 18:45
Pierre G.Pierre G.
3,4231723
answered Mar 7 at 18:45
Pierre G.Pierre G.
3,4231723
answered Mar 7 at 18:45
Pierre G.Pierre G.
3,4231723
3,4231723
add a comment |
add a comment |
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