gsplit: split on single-chars when pattern matches nothing

Also fixes issue when you have fewer fields than the maximum.

1 files changed, 20 insertions, 15 deletions

diff --git a/mew.scm b/mew.scm
index 147b538..c5d200c 100644
--- a/mew.scm
+++ b/mew.scm
@@ -401,21 +401,26 @@
           (n 1)
           (max (optional max -1)))
       (lambda ()
-        (if (or (>= start 0)
-                (and (> max 0) (< n max)))
-          (let ((data (irregex-search pat str start)))
-            (if (and data (or (< max 0) (< n max)))
-              (let ((s (substring str start (irregex-match-start-index data 0))))
-                (set! n (inc n))
-                (set! start (irregex-match-end-index data 0))
-                (when (= start (len str))
-                  (set! start -1))
-                s)
-              (let ((s (substring str start)))
-                (set! n (inc n))
-                (set! start -1)
-                s)))
-          (eof)))))
+        (cond ((< start 0)   (eof))
+              ((<= 0 max n)  (let ((s (substring str start)))
+                               (set! start -1)
+                               s))
+              (else          (let ((data (irregex-search pat str start)))
+                               (if data
+                                 (let ((s (substring str start (irregex-match-start-index data 0))))
+                                   (set! n (inc n))
+                                   (if (equal? s "")
+                                     (begin
+                                       (set! s (substring str start (inc start)))
+                                       (set! start (inc start)))
+                                     (set! start (irregex-match-end-index data 0)))
+                                   (when (= start (len str))
+                                     (set! start -1))
+                                   s)
+                                 (begin
+                                   (let ((s (substring str start)))
+                                     (set! start -1)
+                                     s)))))))))
 
   (define (slurp io)
     (cond ((not io)          (read-string #f (current-input-port)))