Add range function and euler1 example

examples/euler1.lisp

@@ -0,0 +1,6 @@
+;; (defun range (start end)
+;;   (if (< start end)
+;;       (cons start (range (+ 1 start) end))
+;;     (list)))
+
+(write-line (reduce + (filter (lambda (x) (or (zerop (mod x 3)) (zerop (mod x 5)))) (range 1 1000))))

lib/Minilisp.pm

@@ -278,6 +278,10 @@ 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); },