reorg code

2 files changed, 68 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
diff --git a/lib/utils.rkt b/lib/utils.rkt
new file mode 100644
index 0000000..2ce8a51
--- /dev/null
+++ b/lib/utils.rkt
@@ -0,0 +1,36 @@
+#lang racket
+
+(provide get-lines
+         enumerate
+         repeat
+         split-list-by)
+
+(define (repeat n e)
+  (let loop ((i 0) (ret '()))
+    (if (>= i n)
+        ret
+        (loop (+ 1 i) (cons e ret)))))
+
+(define (get-lines fp)
+  (let loop ((lines '()))
+    (define l (read-line fp))
+    (if (eof-object? l)
+        (reverse lines)
+        (loop (cons l lines)))))
+
+(define (enumerate lst)
+  (let loop ((i 1) (ret '()) (remain lst))
+    (if (null? remain)
+        (reverse ret)
+        (loop (+ 1 i) (cons (list (car remain) i) ret) (cdr remain)))))
+
+(define (split-list-by e lst . eq)
+  (define cmp (if (null? eq) equal? eq))
+  (let loop ((ret '())
+             (cur '())
+             (lst lst))
+    (if (null? lst)
+        (reverse (cons (reverse cur) ret))
+        (if (cmp e (car lst))
+            (loop (cons (reverse cur) ret) '() (cdr lst))
+            (loop ret (cons (car lst) cur) (cdr lst))))))