altos/scheme: Add ports. Split scheme code up.

[fw/altos] / src / scheme / ao_scheme_do.scheme

diff --git a/src/scheme/ao_scheme_do.scheme b/src/scheme/ao_scheme_do.scheme
new file mode 100644 (file)
index 0000000..063e4a3
--- /dev/null
+++ b/src/scheme/ao_scheme_do.scheme
@@ -0,0 +1,34 @@
+(define do
+  (macro (vars test . cmds)
+    (define (_step v)
+      (if (null? v)
+         '()
+         (if (null? (cddr (car v)))
+             (_step (cdr v))
+             (cons `(set! ,(caar v) ,(caddr (car v)))
+                   (_step (cdr v))
+                   )
+             )
+         )
+      )
+    `(let ,(map (lambda (v) (list (car v) (cadr v))) vars)
+       (while (not ,(car test))
+             ,@cmds
+             ,@(_step vars)
+             )
+       ,@(cdr test)
+       )
+    )
+  )
+
+(do ((x 1 (+ x 1)))
+    ((= x 10) "done")
+  (display "x: ")
+  (write x)
+  (newline)
+  )
+
+(do ((vec (make-vector 5))
+     (i 0 (+ i 1)))
+    ((= i 5) vec)
+  (vector-set! vec i i))