>From b63e1fd39b258b5de4a71d387fce6007f62355d4 Mon Sep 17 00:00:00 2001
From: Peter Bex <address@hidden>
Date: Sun, 16 Sep 2012 20:11:06 +0200
Subject: [PATCH 4/4] Irregex: Convert strings with charset ranges into large
 SRE ranges instead of alternation of several ranges,
 producing smaller NFAs. (upstream changeset
 e8822a0dbf06)

---
 irregex-core.scm |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/irregex-core.scm b/irregex-core.scm
index e0fc210..18bb50a 100644
--- a/irregex-core.scm
+++ b/irregex-core.scm
@@ -3656,9 +3656,10 @@
             (%irregex-error "not a valid sre char-set" sre)))))))
 
 (define (cset->sre cset)
-  (sre-alternate
-   (map (lambda (x) (list '/ (car x) (cdr x)))
-        (vector->list cset))))
+  (cons '/
+        (fold (lambda (x res) (cons (car x) (cons (cdr x) res)))
+              '()
+              (vector->list cset))))
 
 (define (cset-contains? cset ch)
   (let ((len (vector-length cset)))
-- 
1.7.9.1