introduce modulus arithmetic to std lisp

3 files changed, 18 insertions, 8 deletions

diff --git a/src/grid.rs b/src/grid.rs
index ed1dd83..9baf364 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -93,7 +93,6 @@ impl Grid {
                         (width * cs) as i32,
                         ((width + 2 * height - i) * cs) as i32 / 2,
                     );
-
                     canvas
                         .draw_line(*start + begin_m.into(), *start + end_m.into())
                         .unwrap();
diff --git a/src/lisp/std.lisp b/src/lisp/std.lisp
index 2a042a0..6c5beed 100644
--- a/src/lisp/std.lisp
+++ b/src/lisp/std.lisp
@@ -9,6 +9,18 @@
 (define (cdddddr ls) (cdr (cddddr ls)))
 
 (define (null? ls) (eq? ls '()))
+(define (zero? x) (eq? x 0))
+
+(define (remainder x y)
+  (if (> y x)
+      x
+      (remainder (- x y) y)))
+
+(define (quotient x y)
+  (/ x y))
+
+(define (even? x) (zero? (remainder x 2)))
+(define (odd? x) (not (even? x)))
 
 (define (length ls)
   (if (null? ls)
@@ -45,9 +57,3 @@
 
 (define (sum ls) (fold 0 + ls))
 (define (product ls) (fold 1 * ls))
-
-(define (enumerate start stop step)
-  (if (>= start stop)
-      '()
-      (cons start
-            (enumerate (+ start step) stop step))))
diff --git a/src/main.rs b/src/main.rs
index 220956a..d6f0204 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,9 @@
-#![allow(clippy::upper_case_acronyms, clippy::vec_init_then_push)]
+#![allow(
+    clippy::upper_case_acronyms,
+    clippy::vec_init_then_push,
+    clippy::unsound_collection_transmute
+)]
+
 mod app;
 mod bitmap;
 mod brush;