ref: 32172cdf6a00026675dee9be5c0fa3aef5fdff9d
dir: femtolisp/examples/dict.lsp
; dictionary as binary tree
(defun dict () ())
; node representation ((k . v) L R)
(defun dict-peek (d key nf)
(if (null d) nf
(let ((c (compare key (caar d))))
(cond ((= c 0) (cdar d))
((< c 0) (dict-peek (cadr d) key nf))
(T (dict-peek (caddr d) key nf))))))
(defun dict-get (d key) (dict-peek d key nil))
(defun dict-put (d key v)
(if (null d) (list (cons key v) (dict) (dict))
(let ((c (compare key (caar d))))
(cond ((= c 0) (list (cons key v) (cadr d) (caddr d)))
((< c 0) (list (car d)
(dict-put (cadr d) key v)
(caddr d)))
(T (list (car d)
(cadr d)
(dict-put (caddr d) key v)))))))
; mutable dictionary
(defun dict-nput (d key v)
(if (null d) (list (cons key v) (dict) (dict))
(let ((c (compare key (caar d))))
(cond ((= c 0) (rplacd (car d) v))
((< c 0) (setf (cadr d) (dict-nput (cadr d) key v)))
(T (setf (caddr d) (dict-nput (caddr d) key v))))
d)))
(defun dict-collect (f d)
(if (null d) ()
(cons (f (caar d) (cdar d)) (nconc (dict-collect f (cadr d))
(dict-collect f (caddr d))))))
(defun dict-keys (d) (dict-collect K d))
(defun dict-pairs (d) (dict-collect cons d))
(defun dict-each (f d)
(if (null d) ()
(progn (f (caar d) (cdar d))
(dict-each f (cadr d))
(dict-each f (caddr d)))))
(defun alist-to-dict (a)
(foldl (lambda (p d) (dict-put d (car p) (cdr p)))
(dict) a))