Add and/or.

1 files changed, 18 insertions, 0 deletions

diff --git a/chickadee/graphics/seagull.scm b/chickadee/graphics/seagull.scm
index 6af69eb..b3aef24 100644
--- a/chickadee/graphics/seagull.scm
+++ b/chickadee/graphics/seagull.scm
@@ -301,6 +301,20 @@
          ((l . rest)
           (loop rest `(primcall / ,exp ,(expand l stage env)))))))))
 
+(define (expand:or exps stage env)
+  (match exps
+    (() #f)
+    ((exp . rest)
+     (expand `(let ((x ,exp)) (if x x (or ,@rest)))
+             stage env))))
+
+(define (expand:and exps stage env)
+  (match exps
+    (() #t)
+    ((exp . rest)
+     (expand `(let ((x ,exp)) (if x (and ,@rest) #f))
+             stage env))))
+
 (define (expand:primitive-call operator operands stage env)
   `(primcall ,operator ,@(expand:list operands stage env)))
 
@@ -368,6 +382,10 @@
      (expand:* args stage env))
     (('/ args ...)
      (expand:/ args stage env))
+    (('or exps ...)
+     (expand:or exps stage env))
+    (('and exps ...)
+     (expand:and exps stage env))
     ;; Primitive calls:
     (((? primitive-call-for-stage? operator) args ...)
      (expand:primitive-call operator args stage env))