From 6b40915a50db3159394221a7b6b46cbb74dae606 Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Fri, 16 Sep 2016 06:55:59 -0700
Subject: split-str gains ability to keep separating pieces.

* eval.c (eval_init): Register split-str to split_str_keep,
with optional argument.

* lib.c (split_str_keep): New function, formed from
split_str, with third argument.
(split_str): Reduced to wrapper around split_str_keep.
Thus we don't have to update umpteen existing calls
with an extra nil parameter.

* lib.h (split_str_keep): Declared.

* txr.1: Documented new optional argument of split-str.
---
 lib.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

(limited to 'lib.c')

diff --git a/lib.c b/lib.c
index 7abdb95b..13982b69 100644
--- a/lib.c
+++ b/lib.c
@@ -3807,8 +3807,10 @@ val scat(val sep, ...)
   return ret;
 }
 
-val split_str(val str, val sep)
+val split_str_keep(val str, val sep, val keep_sep)
 {
+  keep_sep = default_bool_arg(keep_sep);
+
   if (regexp(sep)) {
     list_collect_decl (out, iter);
     val pos = zero;
@@ -3824,6 +3826,8 @@ val split_str(val str, val sep)
 
       if (len) {
         pos = plus(pos, len);
+        if (keep_sep)
+          iter = list_collect(iter, sub_str(str, new_pos, pos));
         continue;
       }
       break;
@@ -3846,6 +3850,8 @@ val split_str(val str, val sep)
             val piece = mkustring(one);
             init_str(piece, cstr);
             iter = list_collect(iter, piece);
+            if (keep_sep && *(cstr+1))
+              iter = list_collect(iter, null_string);
           }
 
           gc_hint(str);
@@ -3870,6 +3876,8 @@ val split_str(val str, val sep)
         cstr += span;
         if (psep != 0) {
           cstr += len_sep;
+          if (keep_sep)
+            iter = list_collect(iter, sep);
           continue;
         }
         break;
@@ -3883,6 +3891,11 @@ val split_str(val str, val sep)
   }
 }
 
+val split_str(val str, val sep)
+{
+  return split_str_keep(str, sep, nil);
+}
+
 val split_str_set(val str, val set)
 {
   const wchar_t *cstr = c_str(str);
-- 
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