alists and plists now

bin/alist.slime

@@ -13,10 +13,29 @@
 ;;        key1               key2
 ;;
 ;;        '(((key1 . value1) (key2 . value2)))
+
+;; plist:
+;;        [ |/]
+;;         |
+;;         V
+;;        [ | ]------------->[ | ]-------------> ...
+;;         |                  |
+;;         V                  V
+;;       :key1              value1
+;;
+;;        '((:key1 value1 :key2 value2))
+
 (define key-not-found-index -1)
 
 (define (make-alist)
-  '(()))
+  (set-type
+   '(())
+   :alist))
+
+(define (make-plist)
+  (set-type
+   '(())
+   :plist))
 
 (define (pprint-alist alist)
   (let ((associations (first alist)))
@@ -32,6 +51,19 @@
       (pprint-intern associations))
     (print ")\n")))
 
+(define (pprint-plist plist)
+  (let ((props (first plist)))
+    (define (pprint-intern props)
+      (when props
+        (printf "  "
+                (car props) "->"
+                (cadr props))
+        (pprint-intern (cddr props))))
+    (print "(")
+    (when props
+      (print "\n")
+      (pprint-intern props))
+    (print ")\n")))
 
 (define (alist-get alist key)
   (let ((associations (first alist)))
@@ -76,7 +108,8 @@
 
     (cond ((= index key-not-found-index) (error "key to remove was not found"))
           ((= index 0) (mutate alist (pair (cdar alist) ())))
-          (else (alist-remove!-internal alist index)))))
+          (else (alist-remove!-internal alist index))))
+  alist)
 
 
 (define (alist-set! alist key value)
@@ -93,4 +126,62 @@
             ((null? associations) (alist-set! alist key value))
             (else (alist-set-overwrite-intern
                    (rest associations) key value))))
-    (alist-set-overwrite-intern associations key value)))
+    (alist-set-overwrite-intern associations key value))
+  alist)
+
+
+(define (plist-get plist prop)
+  (let ((props (first plist)))
+    (define (plist-get-intern props prop)
+      (cond ((null? props)
+             (error "property was not found in plist"))
+            ((= (car props) prop)
+             (cadr props))
+            (else (plist-get-intern (cddr props) prop))))
+    (plist-get-intern props prop)))
+
+(define (plist-set! plist prop value)
+  (mutate plist (pair (pair prop (pair value (first plist))) ())))
+
+(define (plist-set-overwrite! plist prop value)
+  (let ((props (first plist)))
+    (define (plist-set-overwrite-intern props prop value)
+      (cond ((= (car props) prop)
+             (mutate (cdr props) (pair value (cddr props))))
+            ((null? props) (plist-set! plist prop value))
+            (else (plist-set-overwrite-intern
+                   (cddr props) prop value))))
+    (plist-set-overwrite-intern props prop value))
+  plist)
+
+(define (plist-find plist prop)
+  (let ((props (first plist)))
+    (define (plist-find-intern props prop current-index)
+      (cond ((null? props) key-not-found-index)
+            ((= (car props) prop) current-index)
+            (else (plist-find-intern (cddr props) prop
+                                     (+ 1 current-index)))))
+    (plist-find-intern props prop 0)))
+
+(define (plist-prop-exists? plist prop)
+  (not (= (plist-find plist prop)
+          key-not-found-index)))
+
+(define (plist-remove! plist prop)
+  (let ((index (plist-find plist prop)))
+    (define (plist-remove!-internal props index)
+      ;; reminder: we only get called if we are not replacing the
+      ;; first element in the alist
+      ;; reminder2: we know that the key exists
+      (if (= index 1)
+          ;; we want to remove the next one, so we set our
+          ;; cdr to the next next one
+           (mutate (cdar props) (pair (cadar props) ;; xD nice meme dude!!!
+                                      (cdr (cdr (cdr (cdar props))))))
+        ;; else cdr-recurse
+        (plist-remove!-internal (cddr props) (- index 1))))
+
+    (cond ((= index key-not-found-index) (error "prop to remove was not found"))
+          ((= index 0) (mutate plist (pair (cddar plist) ())))
+          (else (plist-remove!-internal plist index))))
+  plist)