Sagittarius Users' Reference

(text json patch) - JSON Patch

This library provides JSON Patch procedures.

The specification of JSON Patch is defined by the RFC 6902.

The following example shows simple usage of the library:

This is an input file named example.json.

{
  "id": 1234,
  "data": {
    "datum0": [0, 1, 2],
    "datum1": [3, 4]
  }
}

(import (rnrs) (text json patch) (text json))

(define data-patcher
 (json-patcher 
  '(#(("op" . "replace") ("path" . "/data/datum0") ("value" . "ok"))
    #(("op" . "remove") ("path" . "/data/datum1")))))

(let ((json (call-with-input-file "example.json" json-read)))
  (data-patcher json))

#((id . 1234) (data . #((datum0 . ok))))

Function json-patcher patch

Returns a procedure takes one argument which must be a list or vector representing JSON object. The given patch must be a list of vector which represents JSON patch.

Function json-patch-error? obj

Returns #t if the given obj is an instance of &json-patchcondition.

&json-patch is the base condition of this library. The hierarchy is the following:

&json-patch
 + &json-patch:runtime (path)
   + &json-patch-path-not-found
   + &json-patch-illegal-type
 + &json-patch:compile (patch)

Function json-patch-compile-error? obj

Returns #t if the given obj is an instance of &json-patch:compile condition.

Function json-patch-error? obj

Returns #t if the given obj is an instance of &json-patch:runtime condition.

Function json-patch-path-not-found-error? obj

Returns #t if the given obj is an instance of &json-patch-path-not-found condition.

Function json-patch-path-illegal-type-error? obj

Returns #t if the given obj is an instance of &json-patch-illegal-type condition.

Function json-patch-error-path json-patch-error

Returns the path field of the given json-patch-error if the condition is type of &json-patch-runtime.

Function json-patch-error-patch json-patch-error

Returns the patch field of the given json-patch-error if the condition is type of &json-patch-compile.

Parameter *json-patcher:ignore-no-such-path*

Flag to supress no such path error. The value must be either a symbol or a list of symbol of the name of the patch command. If the value is matched with the patch command, then the runtime doesn't raise a condition.

Function json-diff json0 json1

Creates JSON patch from given json0 and json1.
The returning patch is json1 to json1 format.