Remove non standard range function

Let example define its own range function using do.

examples/euler1.lisp

@@ -1,6 +1,4 @@
-;; (defun range (start end)
-;;   (if (< start end)
-;;       (cons start (range (+ 1 start) end))
-;;     (list)))
+(defun range (start end)
+  (do ((lst (list) (cons i lst)) (i start (+ 1 i))) ((= i end) lst)))
 
 (write-line (reduce + (filter (lambda (x) (or (zerop (mod x 3)) (zerop (mod x 5)))) (range 1 1000))))

lib/Minilisp.pm

@@ -278,10 +278,6 @@ my %stdctx = (
 
     return $number;
   },
-  'range' => sub {
-    my ($start, $end) = @_;
-    return [ $start .. ($end-1) ];
-  },
 
   # String comparison
   'string=' => sub { my ($a, $b) = @_; return to_lisp_bool($a eq $b); },