Hook scanning and indentation functions to find_newline. This helps

to avoid duplicated code and renders more respect to newline cache.
* lisp.h (scan_newline): Prefer ptrdiff_t to EMACS_INT.
* cmds.c (Fforward_line):
* indent.c (scan_for_column, Fcurrent_indentation, indented_beyond_p):
Use find_newline and avoid unnecessary point movements.
* search.c (scan_newline): Implement on top of find_newline.

5 files changed, 40 insertions, 116 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 9e62a8e08a4..2105391755b 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,13 @@
+2013-08-29  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Hook scanning and indentation functions to find_newline.  This helps
+        to avoid duplicated code and renders more respect to newline cache.
+        * lisp.h (scan_newline): Prefer ptrdiff_t to EMACS_INT.
+        * cmds.c (Fforward_line):
+        * indent.c (scan_for_column, Fcurrent_indentation, indented_beyond_p):
+        Use find_newline and avoid unnecessary point movements.
+        * search.c (scan_newline): Implement on top of find_newline.
+
 2013-08-28  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * eval.c (Ffuncall): Fix handling of ((lambda ..) ..) in lexically
diff --git a/src/cmds.c b/src/cmds.c
index ce91877f85e..ee3be79a0ab 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -121,9 +121,7 @@ With positive N, a non-empty line at the end counts as one line
 successfully moved (for the return value).  */)
   (Lisp_Object n)
 {
-  ptrdiff_t opoint = PT, opoint_byte = PT_BYTE;
-  ptrdiff_t pos, pos_byte;
-  EMACS_INT count, shortage;
+  ptrdiff_t opoint = PT, pos, pos_byte, shortage, count;
 
   if (NILP (n))
     count = 1;
@@ -134,16 +132,12 @@ successfully moved (for the return value).  */)
     }
 
   if (count <= 0)
-    shortage = scan_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, count - 1, 1);
+    pos = find_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, count - 1,
+                        &shortage, &pos_byte, 1);
   else
-    shortage = scan_newline (PT, PT_BYTE, ZV, ZV_BYTE, count, 1);
-
-  /* Since scan_newline does TEMP_SET_PT_BOTH,
-     and we want to set PT "for real",
-     go back to the old point and then come back here.  */
-  pos = PT;
-  pos_byte = PT_BYTE;
-  TEMP_SET_PT_BOTH (opoint, opoint_byte);
+    pos = find_newline (PT, PT_BYTE, ZV, ZV_BYTE, count,
+                        &shortage, &pos_byte, 1);
+
   SET_PT_BOTH (pos, pos_byte);
 
   if (shortage > 0
diff --git a/src/indent.c b/src/indent.c
index 6aaf86579d7..891b42788ed 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -510,15 +510,10 @@ scan_for_column (ptrdiff_t *endpos, EMACS_INT *goalcol, ptrdiff_t *prevcol)
   register ptrdiff_t col = 0, prev_col = 0;
   EMACS_INT goal = goalcol ? *goalcol : MOST_POSITIVE_FIXNUM;
   ptrdiff_t end = endpos ? *endpos : PT;
-  ptrdiff_t scan, scan_byte;
-  ptrdiff_t next_boundary;
-  {
-  ptrdiff_t opoint = PT, opoint_byte = PT_BYTE;
-  scan_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, 1);
-  scan = PT, scan_byte = PT_BYTE;
-  SET_PT_BOTH (opoint, opoint_byte);
+  ptrdiff_t scan, scan_byte, next_boundary;
+
+  scan = find_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, NULL, &scan_byte, 1);
   next_boundary = scan;
-  }
 
   window = Fget_buffer_window (Fcurrent_buffer (), Qnil);
   w = ! NILP (window) ? XWINDOW (window) : NULL;
@@ -835,14 +830,10 @@ This is the horizontal position of the character
 following any initial whitespace.  */)
   (void)
 {
-  Lisp_Object val;
-  ptrdiff_t opoint = PT, opoint_byte = PT_BYTE;
-
-  scan_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, 1);
+  ptrdiff_t posbyte;
 
-  XSETFASTINT (val, position_indentation (PT_BYTE));
-  SET_PT_BOTH (opoint, opoint_byte);
-  return val;
+  find_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, NULL, &posbyte, 1);
+  return make_number (position_indentation (posbyte));
 }
 
 static ptrdiff_t
@@ -935,16 +926,13 @@ position_indentation (ptrdiff_t pos_byte)
 bool
 indented_beyond_p (ptrdiff_t pos, ptrdiff_t pos_byte, EMACS_INT column)
 {
-  ptrdiff_t val;
-  ptrdiff_t opoint = PT, opoint_byte = PT_BYTE;
-
-  SET_PT_BOTH (pos, pos_byte);
-  while (PT > BEGV && FETCH_BYTE (PT_BYTE) == '\n')
-    scan_newline (PT - 1, PT_BYTE - 1, BEGV, BEGV_BYTE, -1, 0);
-
-  val = position_indentation (PT_BYTE);
-  SET_PT_BOTH (opoint, opoint_byte);
-  return val >= column;
+  while (pos > BEGV && FETCH_BYTE (pos_byte) == '\n')
+    {
+      DEC_BOTH (pos, pos_byte);
+      pos = find_newline (pos, pos_byte, BEGV, BEGV_BYTE,
+                          -1, NULL, &pos_byte, 0);
+    }
+  return position_indentation (pos_byte) >= column;
 }
 
 DEFUN ("move-to-column", Fmove_to_column, Smove_to_column, 1, 2,
diff --git a/src/lisp.h b/src/lisp.h
index 3dab0d6ddfd..f3a78f48a17 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3834,8 +3834,8 @@ extern ptrdiff_t fast_looking_at (Lisp_Object, ptrdiff_t, ptrdiff_t,
                                   ptrdiff_t, ptrdiff_t, Lisp_Object);
 extern ptrdiff_t find_newline (ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t,
                                ptrdiff_t, ptrdiff_t *, ptrdiff_t *, bool);
-extern EMACS_INT scan_newline (ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t,
-                               EMACS_INT, bool);
+extern ptrdiff_t scan_newline (ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t,
+                               ptrdiff_t, bool);
 extern ptrdiff_t find_newline_no_quit (ptrdiff_t, ptrdiff_t,
                                        ptrdiff_t, ptrdiff_t *);
 extern ptrdiff_t find_before_next_newline (ptrdiff_t, ptrdiff_t,
diff --git a/src/search.c b/src/search.c
index 761c12a364a..99e8d2501fe 100644
--- a/src/search.c
+++ b/src/search.c
@@ -859,88 +859,20 @@ find_newline (ptrdiff_t start, ptrdiff_t start_byte, ptrdiff_t end,
    If ALLOW_QUIT, set immediate_quit.  That's good to do
    except in special cases.  */
 
-EMACS_INT
+ptrdiff_t
 scan_newline (ptrdiff_t start, ptrdiff_t start_byte,
               ptrdiff_t limit, ptrdiff_t limit_byte,
-              EMACS_INT count, bool allow_quit)
+              ptrdiff_t count, bool allow_quit)
 {
-  int direction = ((count > 0) ? 1 : -1);
-
-  unsigned char *cursor;
-  unsigned char *base;
-
-  ptrdiff_t ceiling;
-  unsigned char *ceiling_addr;
-
-  bool old_immediate_quit = immediate_quit;
-
-  if (allow_quit)
-    immediate_quit++;
+  ptrdiff_t charpos, bytepos, shortage;
 
-  if (count > 0)
-    {
-      while (start_byte < limit_byte)
-        {
-          ceiling =  BUFFER_CEILING_OF (start_byte);
-          ceiling = min (limit_byte - 1, ceiling);
-          ceiling_addr = BYTE_POS_ADDR (ceiling) + 1;
-          base = (cursor = BYTE_POS_ADDR (start_byte));
-
-          do
-            {
-              unsigned char *nl = memchr (cursor, '\n', ceiling_addr - cursor);
-              if (! nl)
-                break;
-              if (--count == 0)
-                {
-                  immediate_quit = old_immediate_quit;
-                  start_byte += nl - base + 1;
-                  start = BYTE_TO_CHAR (start_byte);
-                  TEMP_SET_PT_BOTH (start, start_byte);
-                  return 0;
-                }
-              cursor = nl + 1;
-            }
-          while (cursor < ceiling_addr);
-
-          start_byte += ceiling_addr - base;
-        }
-    }
+  charpos = find_newline (start, start_byte, limit, limit_byte,
+                          count, &shortage, &bytepos, allow_quit);
+  if (shortage)
+    TEMP_SET_PT_BOTH (limit, limit_byte);
   else
-    {
-      while (start_byte > limit_byte)
-        {
-          ceiling = BUFFER_FLOOR_OF (start_byte - 1);
-          ceiling = max (limit_byte, ceiling);
-          ceiling_addr = BYTE_POS_ADDR (ceiling);
-          base = (cursor = BYTE_POS_ADDR (start_byte - 1) + 1);
-          while (1)
-            {
-              unsigned char *nl = memrchr (ceiling_addr, '\n',
-                                           cursor - ceiling_addr);
-              if (! nl)
-                break;
-
-              if (++count == 0)
-                {
-                  immediate_quit = old_immediate_quit;
-                  /* Return the position AFTER the match we found.  */
-                  start_byte += nl - base + 1;
-                  start = BYTE_TO_CHAR (start_byte);
-                  TEMP_SET_PT_BOTH (start, start_byte);
-                  return 0;
-                }
-
-              cursor = nl;
-            }
-          start_byte += ceiling_addr - base;
-        }
-    }
-
-  TEMP_SET_PT_BOTH (limit, limit_byte);
-  immediate_quit = old_immediate_quit;
-
-  return count * direction;
+    TEMP_SET_PT_BOTH (charpos, bytepos);
+  return shortage;
 }
 
 /* Like find_newline, but doesn't allow QUITting and doesn't return