Allow + and * to be n-ary.

1 files changed, 18 insertions, 0 deletions

diff --git a/chickadee/graphics/seagull.scm b/chickadee/graphics/seagull.scm
index c7f8ee9..50ac1e8 100644
--- a/chickadee/graphics/seagull.scm
+++ b/chickadee/graphics/seagull.scm
@@ -215,6 +215,20 @@
   (define params* (lookup-all params env*))
   `(lambda ,params* ,(expand body env*)))
 
+(define (expand:+ args env)
+  (match args
+    (() 0)
+    ((n) (expand n env))
+    ((n . rest)
+     `(primcall + ,(expand n env) ,(expand:+ rest env)))))
+
+(define (expand:* args env)
+  (match args
+    (() 1)
+    ((n) (expand n env))
+    ((n . rest)
+     `(primcall * ,(expand n env) ,(expand:* rest env)))))
+
 (define (expand:primitive-call operator operands env)
   `(primcall ,operator ,@(expand:list operands env)))
 
@@ -248,6 +262,10 @@
     ;; Macros:
     (('let* (bindings ...) body)
      (expand:let* bindings body env))
+    (('+ args ...)
+     (expand:+ args env))
+    (('* args ...)
+     (expand:* args env))
     ;; Primitive calls:
     (((? primitive-call? operator) args ...)
      (expand:primitive-call operator args env))