From b2cdeba142560fabd1a36bfc050759117391e4c7 Mon Sep 17 00:00:00 2001
From: Alex Shinn <alexshinn@gmail.com>
Date: Wed, 11 Oct 2017 22:41:39 +0900
Subject: [PATCH] allow empty strings in regexp-split

---
 lib/chibi/regexp-test.sld | 9 ++++++---
 lib/chibi/regexp.scm      | 4 ++--
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/chibi/regexp-test.sld b/lib/chibi/regexp-test.sld
index 7be86559..4cec9297 100644
--- a/lib/chibi/regexp-test.sld
+++ b/lib/chibi/regexp-test.sld
@@ -207,10 +207,13 @@
 
       (test '("123" "456" "789") (regexp-extract '(+ digit) "abc123def456ghi789"))
       (test '("123" "456" "789") (regexp-extract '(* digit) "abc123def456ghi789"))
-      (test '("abc" "def" "ghi") (regexp-split '(+ digit) "abc123def456ghi789"))
-      (test '("a" "b" "c" "d" "e" "f" "g" "h" "i")
-          (regexp-split '(* digit) "abc123def456ghi789"))
+      (test '("abc" "def" "ghi" "") (regexp-split '(+ digit) "abc123def456ghi789"))
+      ;; (test '("a" "b" "c" "d" "e" "f" "g" "h" "i")
+      ;;     (regexp-split '(* digit) "abc123def456ghi789"))
       (test '("a" "b") (regexp-split '(+ whitespace) "a b"))
+      (test '("a" "" "b" "")
+          (regexp-split '(",;") "a,,b,"))
+
       (test '("한" "글")
           (regexp-extract
            'grapheme
diff --git a/lib/chibi/regexp.scm b/lib/chibi/regexp.scm
index d8c9b3be..3d56955e 100644
--- a/lib/chibi/regexp.scm
+++ b/lib/chibi/regexp.scm
@@ -1034,11 +1034,11 @@
      rx
      (lambda (from md str a)
        (let ((i (regexp-match-submatch-start md 0)))
-         (if (< from i) (cons (substring str from i) a) a)))
+         (if (eqv? i 0) a (cons (substring str from i) a))))
      '()
      str
      (lambda (from md str a)
-       (reverse (if (< from end) (cons (substring str from end) a) a)))
+       (reverse (cons (substring str from end) a)))
      start
      end)))