JSON.Patch

implements RFC 6902 JSON Patch, a JSON array of operation objects describing a sequence of changes to a document.

apply

defn

(Fn [(Ref JSON a), (Ref JSON b)] (Result JSON JSON.PatchError))

                        (apply doc patch)

applies an RFC 6902 JSON Patch to doc, returning a (Result JSON PatchError). Operations are applied in order and the patch is atomic: on failure doc is untouched and the error names the operation index.

(JSON.Patch.apply &doc &patch)

diff

defn

(Fn [(Ref JSON a), (Ref JSON a)] JSON)

                        (diff a b)

builds an RFC 6902 patch taking a to b, the inverse of apply: applying the result to a returns b for any two documents.

Objects are compared member by member, emitting add for a key only in b, remove for a key only in a, and nothing for members the two share. Arrays are compared element by element, growing with add and shrinking with remove. Everything else that differs becomes a replace, so two documents of different kinds diff to one replace of the whole document.

(JSON.Patch.apply &a &(JSON.Patch.diff &a &b))