From 1e363a8ea5ac09455f3a44fbb646b5af32bca51c Mon Sep 17 00:00:00 2001 From: =?utf8?q?Simen=20Heggest=C3=B8yl?= Date: Thu, 12 Nov 2015 18:30:37 +0100 Subject: [PATCH] Enable sorting of JSON object keys when encoding * lisp/json.el (json-encoding-object-sort-predicate): New variable for specifying a sorting predicate for JSON objects during encoding. (json--plist-to-alist): New utility function. (json-encode-hash-table): Re-use `json-encode-alist' when object keys are to be sorted. (json-encode-alist): Sort output by `json-encoding-object-sort-predicate, when set. (json-encode-plist): Re-use `json-encode-alist' when object keys are to be sorted. (json-pretty-print-buffer-ordered): New command to pretty print the buffer with object keys sorted alphabetically. (json-pretty-print-ordered): New command to pretty print the region with object keys sorted alphabetically. * test/automated/json-tests.el (test-json-plist-to-alist) (test-json-encode-plist, test-json-encode-hash-table) (test-json-encode-alist-with-sort-predicate) (test-json-encode-plist-with-sort-predicate): New tests. * etc/NEWS: Add an entry for the new commands. --- etc/NEWS | 4 ++ lisp/json.el | 117 +++++++++++++++++++++++------------ test/automated/json-tests.el | 29 +++++++++ 3 files changed, 111 insertions(+), 39 deletions(-) diff --git a/etc/NEWS b/etc/NEWS index f3df92e51e5..46910b021c7 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -332,6 +332,10 @@ unlike `bookmark-set' which silently updates an existing bookmark. --- *** `json-pretty-print' and `json-pretty-print-buffer' now maintain the ordering of object keys by default. +--- +*** New commands `json-pretty-print-ordered' and +`json-pretty-print-buffer-ordered' pretty prints JSON objects with +object keys sorted alphabetically. ** You can recompute the VC state of a file buffer with `M-x vc-refresh-state' ** Prog mode has some support for multi-mode indentation. diff --git a/lisp/json.el b/lisp/json.el index 97cf9934c34..0214a3e3a4d 100644 --- a/lisp/json.el +++ b/lisp/json.el @@ -52,6 +52,8 @@ ;;; Code: +(require 'map) + ;; Parameters (defvar json-object-type 'alist @@ -111,6 +113,13 @@ Used only when `json-encoding-pretty-print' is non-nil.") "If non-nil, ] and } closings will be formatted lisp-style, without indentation.") +(defvar json-encoding-object-sort-predicate nil + "Sorting predicate for JSON object keys during encoding. +If nil, no sorting is performed. Else, JSON object keys are +ordered by the specified sort predicate during encoding. For +instance, setting this to `string<' will have JSON object keys +ordered alphabetically.") + (defvar json-pre-element-read-function nil "Function called (if non-nil) by `json-read-array' and `json-read-object' right before reading a JSON array or object, @@ -159,6 +168,15 @@ Unlike `reverse', this keeps the property-value pairs intact." (push prop res))) res)) +(defun json--plist-to-alist (plist) + "Return an alist of the property-value pairs in PLIST." + (let (res) + (while plist + (let ((prop (pop plist)) + (val (pop plist))) + (push (cons prop val) res))) + (nreverse res))) + (defmacro json--with-indentation (body) `(let ((json--encoding-current-indentation (if json-encoding-pretty-print @@ -492,32 +510,39 @@ Please see the documentation of `json-object-type' and `json-key-type'." (defun json-encode-hash-table (hash-table) "Return a JSON representation of HASH-TABLE." - (format "{%s%s}" - (json-join - (let (r) - (json--with-indentation - (maphash - (lambda (k v) - (push (format - (if json-encoding-pretty-print - "%s%s: %s" - "%s%s:%s") - json--encoding-current-indentation - (json-encode-key k) - (json-encode v)) - r)) - hash-table)) - r) - json-encoding-separator) - (if (or (not json-encoding-pretty-print) - json-encoding-lisp-style-closings) - "" - json--encoding-current-indentation))) + (if json-encoding-object-sort-predicate + (json-encode-alist (map-into hash-table 'list)) + (format "{%s%s}" + (json-join + (let (r) + (json--with-indentation + (maphash + (lambda (k v) + (push (format + (if json-encoding-pretty-print + "%s%s: %s" + "%s%s:%s") + json--encoding-current-indentation + (json-encode-key k) + (json-encode v)) + r)) + hash-table)) + r) + json-encoding-separator) + (if (or (not json-encoding-pretty-print) + json-encoding-lisp-style-closings) + "" + json--encoding-current-indentation)))) ;; List encoding (including alists and plists) (defun json-encode-alist (alist) "Return a JSON representation of ALIST." + (when json-encoding-object-sort-predicate + (setq alist + (sort alist (lambda (a b) + (funcall json-encoding-object-sort-predicate + (car a) (car b)))))) (format "{%s%s}" (json-join (json--with-indentation @@ -537,25 +562,27 @@ Please see the documentation of `json-object-type' and `json-key-type'." (defun json-encode-plist (plist) "Return a JSON representation of PLIST." - (let (result) - (json--with-indentation - (while plist - (push (concat - json--encoding-current-indentation - (json-encode-key (car plist)) - (if json-encoding-pretty-print - ": " - ":") - (json-encode (cadr plist))) - result) - (setq plist (cddr plist)))) - (concat "{" - (json-join (nreverse result) json-encoding-separator) - (if (and json-encoding-pretty-print - (not json-encoding-lisp-style-closings)) + (if json-encoding-object-sort-predicate + (json-encode-alist (json--plist-to-alist plist)) + (let (result) + (json--with-indentation + (while plist + (push (concat json--encoding-current-indentation - "") - "}"))) + (json-encode-key (car plist)) + (if json-encoding-pretty-print + ": " + ":") + (json-encode (cadr plist))) + result) + (setq plist (cddr plist)))) + (concat "{" + (json-join (nreverse result) json-encoding-separator) + (if (and json-encoding-pretty-print + (not json-encoding-lisp-style-closings)) + json--encoding-current-indentation + "") + "}")))) (defun json-encode-list (list) "Return a JSON representation of LIST. @@ -698,6 +725,18 @@ Advances point just past JSON object." (txt (delete-and-extract-region begin end))) (insert (json-encode (json-read-from-string txt)))))) +(defun json-pretty-print-buffer-ordered () + "Pretty-print current buffer with object keys ordered." + (interactive) + (let ((json-encoding-object-sort-predicate 'string<)) + (json-pretty-print-buffer))) + +(defun json-pretty-print-ordered (begin end) + "Pretty-print the region with object keys ordered." + (interactive "r") + (let ((json-encoding-object-sort-predicate 'string<)) + (json-pretty-print begin end))) + (provide 'json) ;;; json.el ends here diff --git a/test/automated/json-tests.el b/test/automated/json-tests.el index fa1f5484eec..8f0cd6f0857 100644 --- a/test/automated/json-tests.el +++ b/test/automated/json-tests.el @@ -28,11 +28,40 @@ (should (equal (json--plist-reverse '(:a 1 :b 2 :c 3)) '(:c 3 :b 2 :a 1)))) +(ert-deftest test-json-plist-to-alist () + (should (equal (json--plist-to-alist '()) '())) + (should (equal (json--plist-to-alist '(:a 1)) '((:a . 1)))) + (should (equal (json--plist-to-alist '(:a 1 :b 2 :c 3)) + '((:a . 1) (:b . 2) (:c . 3))))) + +(ert-deftest test-json-encode-plist () + (let ((plist '(:a 1 :b 2))) + (should (equal (json-encode plist) "{\"a\":1,\"b\":2}")))) + (ert-deftest json-encode-simple-alist () (should (equal (json-encode '((a . 1) (b . 2))) "{\"a\":1,\"b\":2}"))) +(ert-deftest test-json-encode-hash-table () + (let ((hash-table (make-hash-table)) + (json-encoding-object-sort-predicate 'string<)) + (puthash :a 1 hash-table) + (puthash :b 2 hash-table) + (puthash :c 3 hash-table) + (should (equal (json-encode hash-table) + "{\"a\":1,\"b\":2,\"c\":3}")))) + +(ert-deftest test-json-encode-alist-with-sort-predicate () + (let ((alist '((:c . 3) (:a . 1) (:b . 2))) + (json-encoding-object-sort-predicate 'string<)) + (should (equal (json-encode alist) "{\"a\":1,\"b\":2,\"c\":3}")))) + +(ert-deftest test-json-encode-plist-with-sort-predicate () + (let ((plist '(:c 3 :a 1 :b 2)) + (json-encoding-object-sort-predicate 'string<)) + (should (equal (json-encode plist) "{\"a\":1,\"b\":2,\"c\":3}")))) + (ert-deftest json-read-simple-alist () (let ((json-object-type 'alist)) (should (equal (json-read-from-string "{\"a\": 1, \"b\": 2}") -- 2.39.2