There are some inconsistencies between flush-lines and keep-lines, if they operate on a region that contains partial lines.
If point is not at the beginning of a line, `flush-lines' gets rid of the line point is on if and only if the part of the line _after_ point contains a match for the regexp. `keep-lines' unconditionally keeps that line. This difference in philosophy might not be too bad and could just be documented. With transient mark mode enabled and an active region, a partial line at the beginning of the region is treated as above. Might again not be too bad. `flush-lines' erases a partial line at the end of the region if and only if the part _inside the region_ contains a match for regexp, thereby being consistent with its own behavior for the line at the beginning of the region. But the behavior of `keep-lines' there seems very unexpected. Take a buffer with the following three lines: 12 34 56 If the region starts at 2 and ends at 5 (both _inclusive_) M-x keep-lines RET 7 RET results in: 12 6 The last line got _partially_ erased. The docs seem to suggest that keep-lines should keep or erase entire lines, not parts of them, even in the presence of partial lines. To make the behavior of `keep-lines' symmetric at both ends of the region, the last line should be unconditionally kept in its entirety. Maybe the difference with flush-lines could then be explained by the principle: If you are not sure, just by looking at the region, whether to erase or keep, then keep the line. You can never be sure by looking only at part of a line that the entire line does _not_ contain a match, so keep-lines always needs to keep all partial lines. But if the part you are seeing contains a match, you _know_ that flush-lines needs to erase it. Sincerely, Luc. _______________________________________________ Emacs-devel mailing list Emacs-devel@gnu.org http://lists.gnu.org/mailman/listinfo/emacs-devel
