From 93b855b22cb4edb89a1a4bf3a215010b1d6a02f1 Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Fri, 19 Aug 2016 23:05:01 -0400
Subject: [PATCH] Fix problems with compilation

---
 srfi/1.scm | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/srfi/1.scm b/srfi/1.scm
index ad447154..36a10548 100644
--- a/srfi/1.scm
+++ b/srfi/1.scm
@@ -208,6 +208,13 @@
 ;;;
 ;;; The SRFI discussion record contains more discussion on this topic.
 
+(define-syntax :optional
+  (syntax-rules ()
+    ((:optional rest default-exp)
+     (let ((maybe-arg rest))
+       (cond ((null? maybe-arg) default-exp)
+             ((null? (cdr maybe-arg)) (car maybe-arg))
+             (else (error "too many optional arguments" maybe-arg)))))))
 
 ;;; Constructors
 ;;;;;;;;;;;;;;;;
@@ -271,7 +278,13 @@
 (define (iota count . maybe-start+step)
   (check-arg integer? count iota)
   (if (< count 0) (error "Negative step count" iota count))
-  (let-optionals maybe-start+step ((start 0) (step 1))
+  (let ((start 0) 
+        (step 1))
+    (cond
+      ((not (null? maybe-start+step))
+       (set! start (car maybe-start+step))
+       (if (not (null? (cdr maybe-start+step)))
+           (set! step (cadr maybe-start+step)))))
     (check-arg number? start iota)
     (check-arg number? step iota)
     (let loop ((n 0) (r '()))