narrow-buffer(2)

NAME

narrow-buffer - Hide buffer lines

SYNOPSIS

n narrow-buffer

DESCRIPTION

The effect of narrow-buffer depends on the argument given, defined as follows:-

1


Removes all narrows in the current buffer (Default).

2


Removes the current line's narrow.

3


Narrow to region. Hides all but the lines of test in the current buffer from the mark position to the current cursor position, effectively 'narrowing' the buffer to the remaining text.

4


Narrow out region. Hides the lines of test in the current buffer from the mark position to the current cursor position, opposite to argument 3.

When a narrow is created the buffer mode narrow(2m) is automatically set, when the last is removed this mode is deleted.

For example, if the buffer contains the following text:

1 Richmond 
2 Lafayette 
3 Bloomington 
4 Indianapolis 
5 Gary 
6 

If the mark is on line 2 and the current point is on line 4, executing:-

4 narrow-buffer 

Creates one narrow, narrowing out line 2 and 3. Line 4 becomes the narrow anchor line, when the narrow is removed lines 2 and 3 will be inserted before line 4. The buffer will become:-

1 Richmond 
4 Indianapolis 
5 Gary 

If instead the following was executed:-

3 narrow-buffer 

Two narrows are created, the first narrowing out line 4 and 5 (line 6, the last line, being the anchor line) the second narrowing out line 1 (line 2 being the anchor line). The buffer will become:-

2 Lafayette 
3 Bloomington 
6 

Executing narrow-buffer with an argument of 2 will only work on the anchor lines, namely 4 in the first example and 2 and 6 in the second.

NOTES

Alpha mark set by set-alpha-mark(2) in text which is subsequently narrowed out will automatically remove the narrow if the user returns to the mark using goto-alpha-mark(2).

get-next-line(2) operates on the unnarrowed buffer and will remove any narrows hiding the 'next' line.

EXAMPLE

c-hash-eval(3) macro defined in cmacros.emf uses narrow-buffer to hide regions of source code which has been #defined out, improving readability.

vm(3) defined in vm.emf uses narrow-buffer with appropriate arguments to append-buffer(2) and write-buffer(2) to write out only parts of the current buffer.

SEE ALSO

narrow(2m), set-mark(2), set-alpha-mark(2), get-next-line(2), c-hash-eval(3), vm(3).

(c) Copyright JASSPA 1999
Last Modified: 1999/01/13
Generated On: 1999/12/01