From 140b69dfc653c27b59570c9050e8b0909fd296b9 Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@pobox.com>
Date: Tue, 26 Dec 2017 20:51:31 +0100
Subject: [PATCH] Refactor list->seq to make return arity apparent

* module/language/tree-il.scm (list->seq): Change to let tail of seq
  indicate number of values.
---
 module/language/tree-il.scm | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/module/language/tree-il.scm b/module/language/tree-il.scm
index 5fb0ce05f..88e943b75 100644
--- a/module/language/tree-il.scm
+++ b/module/language/tree-il.scm
@@ -139,9 +139,12 @@
 
 ;; A helper.
 (define (list->seq loc exps)
-  (if (null? (cdr exps))
-      (car exps)
-      (make-seq loc (car exps) (list->seq #f (cdr exps)))))
+  (match exps
+    ((exp . exps)
+     (let lp ((head exp) (tail exps))
+       (match tail
+         (() head)
+         ((exp . tail) (lp (make-seq loc head exp) tail)))))))