Variable: long-line-optimizations-region-size
long-line-optimizations-region-size is a variable defined in buffer.c.
Value
500000
Documentation
Region size for narrowing in buffers with long lines.
This variable has effect only in buffers in which
long-line-optimizations-p is non-nil. For performance reasons, in
such buffers, the fontification-functions, pre-command-hook and
post-command-hook hooks are executed on a narrowed buffer around
point, as if they were called in a with-restriction form with a label.
This variable specifies the size of the narrowed region around point.
To disable that narrowing, set this variable to 0.
See also long-line-optimizations-bol-search-limit.
There is no reason to change that value except for debugging purposes.
Probably introduced at or before Emacs version 29.1.
Source Code
// Defined in /usr/src/emacs/src/buffer.c
DEFVAR_INT ("long-line-optimizations-region-size",
long_line_optimizations_region_size,
doc: /* Region size for narrowing in buffers with long lines.
This variable has effect only in buffers in which
`long-line-optimizations-p' is non-nil. For performance reasons, in
such buffers, the `fontification-functions', `pre-command-hook' and
`post-command-hook' hooks are executed on a narrowed buffer around
point, as if they were called in a `with-restriction' form with a label.
This variable specifies the size of the narrowed region around point.
To disable that narrowing, set this variable to 0.
See also `long-line-optimizations-bol-search-limit'.
There is no reason to change that value except for debugging purposes. */);