diff options
Diffstat (limited to 'emacs/guix-utils.el')
| -rw-r--r-- | emacs/guix-utils.el | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/emacs/guix-utils.el b/emacs/guix-utils.el index 3748350b87..fbe0a613da 100644 --- a/emacs/guix-utils.el +++ b/emacs/guix-utils.el @@ -307,7 +307,7 @@ Example: ,@body))) -;;; Alist accessors +;;; Alist procedures (defmacro guix-define-alist-accessor (name assoc-fun) "Define NAME function to access alist values using ASSOC-FUN." @@ -325,6 +325,48 @@ accessed with KEYS." (guix-define-alist-accessor guix-assq-value assq) (guix-define-alist-accessor guix-assoc-value assoc) +(defun guix-alist-put (value alist &rest keys) + "Put (add or replace if exists) VALUE to ALIST using KEYS. +Return the new alist. + +ALIST is alist of alists of alists ... which can be consecutively +accessed with KEYS. + +Example: + + (guix-alist-put + 'foo + '((one (a . 1) (b . 2)) + (two (m . 7) (n . 8))) + 'one 'b) + + => ((one (a . 1) (b . foo)) + (two (m . 7) (n . 8)))" + (or keys (error "Keys should be specified")) + (guix-alist-put-1 value alist keys)) + +(defun guix-alist-put-1 (value alist keys) + "Subroutine of `guix-alist-put'." + (cond + ((null keys) + value) + ((null alist) + (list (cons (car keys) + (guix-alist-put-1 value nil (cdr keys))))) + ((eq (car keys) (caar alist)) + (cons (cons (car keys) + (guix-alist-put-1 value (cdar alist) (cdr keys))) + (cdr alist))) + (t + (cons (car alist) + (guix-alist-put-1 value (cdr alist) keys))))) + +(defun guix-alist-put! (value variable &rest keys) + "Modify alist VARIABLE (symbol) by putting VALUE using KEYS. +See `guix-alist-put' for details." + (set variable + (apply #'guix-alist-put value (symbol-value variable) keys))) + ;;; Diff |