JSON.Pointer

implements RFC 6901 JSON Pointer, addressing a value inside a JSON document with a string such as /foo/0/bar.

escape

defn

(Fn [(Ref String a)] String)

                        (escape s)

encodes a single reference token, turning ~ into ~0 and / into ~1 so it can be embedded in a pointer string.

get

defn

(Fn [(Ref JSON a), (Ref String b)] (Maybe JSON))

                        (get doc pointer)

resolves an RFC 6901 JSON Pointer against doc, returning a copy of the addressed value or Nothing.

The empty pointer addresses the whole document. Object keys match by string. An array token must be 0 or a positive integer without a leading zero; the - end-of-array token, out-of-range indices, indexing a non-container, and invalid pointers all yield Nothing.

(JSON.Pointer.get &doc "/foo/0")

parse

defn

(Fn [(Ref String a)] (Maybe (Array String)))

                        (parse p)

parses a pointer string into its decoded reference tokens.

The empty string yields an empty token array, which addresses the whole document. A non-empty pointer must begin with /, otherwise Nothing is returned. Empty tokens are preserved: a trailing / addresses the empty-string key.

unescape

defn

(Fn [(Ref String a)] String)

                        (unescape s)

decodes a single reference token, turning ~1 back into / and ~0 back into ~ in a single left-to-right pass, per RFC 6901.