master f117b5df4d: Add new functions eol and bol

[Lars Ingebrigtsen]

branch: master
commit f117b5df4dc69a38a5568c5926c1e417a35314eb
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Add new functions eol and bol
    
    * doc/lispref/positions.texi (Text Lines): Document them
    * lisp/emacs-lisp/shortdoc.el: Mention them, and also the
    buffer/line predicates.
    
    * src/editfns.c (bol): New function.
    (Fbol): New defun.
    (Fline_beginning_position): Use `bol'.
    (eol): New function.
    (Feol): New defun.
    (Fline_end_position): Use `eol'.
---
 doc/lispref/positions.texi  | 10 +++++
 etc/NEWS                    |  5 +++
 lisp/emacs-lisp/shortdoc.el | 12 ++++++
 src/editfns.c               | 98 ++++++++++++++++++++++++++++++---------------
 4 files changed, 93 insertions(+), 32 deletions(-)

diff --git a/doc/lispref/positions.texi b/doc/lispref/positions.texi
index 333c8e19a0..53846ed297 100644
--- a/doc/lispref/positions.texi
+++ b/doc/lispref/positions.texi
@@ -387,6 +387,16 @@ Return the position that @code{(end-of-line @var{count})}
 would move to.
 @end defun
 
+@defun bol &optional count
+Like @code{line-beginning-position}, but ignores fields (and is more
+efficient).
+@end defun
+
+@defun eol &optional count
+Like @code{line-end-position}, but ignores fields (and is more
+efficient).
+@end defun
+
 @deffn Command forward-line &optional count
 @cindex beginning of line
 This function moves point forward @var{count} lines, to the beginning of
diff --git a/etc/NEWS b/etc/NEWS
index 511687a174..e5260e4e7e 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -2587,6 +2587,11 @@ patcomp.el, pc-mode.el, pc-select.el, s-region.el, and 
sregex.el.
 
 * Lisp Changes in Emacs 29.1
 
++++
+** New functions 'eol' and 'bol'.
+These are like 'line-end-position' and 'line-beginning-position'
+(respectively), but ignore fields (and are more efficient).
+
 +++
 ** New function 'compiled-function-p'.
 This returns non-nil if its argument is either a built-in, or a
diff --git a/lisp/emacs-lisp/shortdoc.el b/lisp/emacs-lisp/shortdoc.el
index d187af9ac8..acf294ede1 100644
--- a/lisp/emacs-lisp/shortdoc.el
+++ b/lisp/emacs-lisp/shortdoc.el
@@ -941,12 +941,24 @@ A FUNC form can have any number of `:no-eval' (or 
`:no-value'),
    :eval (point-min))
   (point-max
    :eval (point-max))
+  (eol
+   :eval (eol))
+  (bol
+   :eval (bol))
+  (bolp
+   :eval (bolp))
+  (eolp
+   :eval (eolp))
   (line-beginning-position
    :eval (line-beginning-position))
   (line-end-position
    :eval (line-end-position))
   (buffer-size
    :eval (buffer-size))
+  (bobp
+   :eval (bobp))
+  (eobp
+   :eval (eobp))
   "Moving Around"
   (goto-char
    :no-eval (goto-char (point-max))
diff --git a/src/editfns.c b/src/editfns.c
index 4fb82485ab..1e07b0b655 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -709,9 +709,28 @@ Field boundaries are not noticed if 
`inhibit-field-text-motion' is non-nil.  */)
 }
 
 
-DEFUN ("line-beginning-position",
-       Fline_beginning_position, Sline_beginning_position, 0, 1, 0,
-       doc: /* Return the character position of the first character on the 
current line.
+static ptrdiff_t
+bol (Lisp_Object n, ptrdiff_t *out_count)
+{
+  ptrdiff_t bytepos, charpos, count;
+
+  if (NILP (n))
+    count = 0;
+  else if (FIXNUMP (n))
+    count = clip_to_bounds (-BUF_BYTES_MAX, XFIXNUM (n) - 1, BUF_BYTES_MAX);
+  else
+    {
+      CHECK_INTEGER (n);
+      count = NILP (Fnatnump (n)) ? -BUF_BYTES_MAX : BUF_BYTES_MAX;
+    }
+  if (out_count)
+    *out_count = count;
+  scan_newline_from_point (count, &charpos, &bytepos);
+  return charpos;
+}
+
+DEFUN ("bol", Fbol, Sbol, 0, 1, 0,
+       doc: /* Return the position of the first character on the current line.
 With optional argument N, scan forward N - 1 lines first.
 If the scan reaches the end of the buffer, return that position.
 
@@ -720,6 +739,17 @@ position of the first character in logical order, i.e. the 
smallest
 character position on the logical line.  See `vertical-motion' for
 movement by screen lines.
 
+This function does not move point.  Also see `line-beginning-position'.  */)
+  (Lisp_Object n)
+{
+  return make_fixnum (bol (n, NULL));
+}
+
+DEFUN ("line-beginning-position",
+       Fline_beginning_position, Sline_beginning_position, 0, 1, 0,
+       doc: /* Return the position of the first character in the current 
line/field.
+This function is like `bol' (which see), but respects fields.
+
 This function constrains the returned position to the current field
 unless that position would be on a different line from the original,
 unconstrained result.  If N is nil or 1, and a front-sticky field
@@ -729,28 +759,33 @@ boundaries, bind `inhibit-field-text-motion' to t.
 This function does not move point.  */)
   (Lisp_Object n)
 {
-  ptrdiff_t charpos, bytepos, count;
+  ptrdiff_t count, charpos = (bol (n, &count));
+  /* Return END constrained to the current input field.  */
+  return Fconstrain_to_field (make_fixnum (charpos), make_fixnum (PT),
+                             count != 0 ? Qt : Qnil,
+                             Qt, Qnil);
+}
+
+static ptrdiff_t
+eol (Lisp_Object n)
+{
+  ptrdiff_t count;
 
   if (NILP (n))
-    count = 0;
+    count = 1;
   else if (FIXNUMP (n))
-    count = clip_to_bounds (-BUF_BYTES_MAX, XFIXNUM (n) - 1, BUF_BYTES_MAX);
+    count = clip_to_bounds (-BUF_BYTES_MAX, XFIXNUM (n), BUF_BYTES_MAX);
   else
     {
       CHECK_INTEGER (n);
       count = NILP (Fnatnump (n)) ? -BUF_BYTES_MAX : BUF_BYTES_MAX;
     }
-
-  scan_newline_from_point (count, &charpos, &bytepos);
-
-  /* Return END constrained to the current input field.  */
-  return Fconstrain_to_field (make_fixnum (charpos), make_fixnum (PT),
-                             count != 0 ? Qt : Qnil,
-                             Qt, Qnil);
+  return find_before_next_newline (PT, 0, count - (count <= 0),
+                                  NULL);
 }
 
-DEFUN ("line-end-position", Fline_end_position, Sline_end_position, 0, 1, 0,
-       doc: /* Return the character position of the last character on the 
current line.
+DEFUN ("eol", Feol, Seol, 0, 1, 0,
+       doc: /* Return the position of the last character on the current line.
 With argument N not nil or 1, move forward N - 1 lines first.
 If scan reaches end of buffer, return that position.
 
@@ -758,6 +793,19 @@ This function ignores text display directionality; it 
returns the
 position of the last character in logical order, i.e. the largest
 character position on the line.
 
+This function does not move point.  Also see `line-end-position'.  */)
+  (Lisp_Object n)
+{
+  return make_fixnum (eol (n));
+}
+
+DEFUN ("line-end-position", Fline_end_position, Sline_end_position, 0, 1, 0,
+       doc: /* Return the position of the last character in the current 
line/field.
+With argument N not nil or 1, move forward N - 1 lines first.
+If scan reaches end of buffer, return that position.
+
+This function is like `eol' (which see), but respects fields.
+
 This function constrains the returned position to the current field
 unless that would be on a different line from the original,
 unconstrained result.  If N is nil or 1, and a rear-sticky field ends
@@ -767,24 +815,8 @@ boundaries bind `inhibit-field-text-motion' to t.
 This function does not move point.  */)
   (Lisp_Object n)
 {
-  ptrdiff_t clipped_n;
-  ptrdiff_t end_pos;
-  ptrdiff_t orig = PT;
-
-  if (NILP (n))
-    clipped_n = 1;
-  else if (FIXNUMP (n))
-    clipped_n = clip_to_bounds (-BUF_BYTES_MAX, XFIXNUM (n), BUF_BYTES_MAX);
-  else
-    {
-      CHECK_INTEGER (n);
-      clipped_n = NILP (Fnatnump (n)) ? -BUF_BYTES_MAX : BUF_BYTES_MAX;
-    }
-  end_pos = find_before_next_newline (orig, 0, clipped_n - (clipped_n <= 0),
-                                     NULL);
-
   /* Return END_POS constrained to the current input field.  */
-  return Fconstrain_to_field (make_fixnum (end_pos), make_fixnum (orig),
+  return Fconstrain_to_field (make_fixnum (eol (n)), make_fixnum (PT),
                              Qnil, Qt, Qnil);
 }
 
@@ -4610,6 +4642,8 @@ with an optional argument LOCK non-nil.  */);
 
   defsubr (&Sline_beginning_position);
   defsubr (&Sline_end_position);
+  defsubr (&Sbol);
+  defsubr (&Seol);
 
   defsubr (&Ssave_excursion);
   defsubr (&Ssave_current_buffer);