reorg code

1 files changed, 32 insertions, 0 deletions

diff --git a/lib/obj.rkt b/lib/obj.rkt
new file mode 100644
index 0000000..8ffc401
--- /dev/null
+++ b/lib/obj.rkt
@@ -0,0 +1,32 @@
+#lang racket
+
+(provide obj-maker
+         obj-set
+         obj-show)
+
+(define (alist->obj alist)
+  (λ key
+    (if (null? key)
+        alist
+        (cadr (assoc (car key) alist)))))
+
+(define (obj-maker . fields)
+  (λ inits
+    (define alist (map list fields inits))
+    (alist->obj alist)))
+
+(define (obj-set record key value)
+  (define alist (record))
+  (define new-alist
+    (let loop ((new-list '()) (cur alist) (is-set #f))
+      (if (null? cur)
+          (if is-set
+              new-list
+              (cons (list key value) new-list))
+          (let ()
+            (if (eq? key (caar cur))
+                (loop (cons (list key value) new-list) (cdr cur) #t)
+                (loop (cons (car cur) new-list) (cdr cur) is-set))))))
+  (alist->obj new-alist))
+
+(define (obj-show x) (x))
\ No newline at end of file