This provides room for three-digit line numbers, plus a delimiting space, on
an 80-character terminal. If additional lines numbers are needed, the file
is probably too big.
This is also more polite for e-mail.
And here come the rationale for this sensitive topic:
- Source code should wrap at 80 characters; be polite and give room for
line numbering. Four characters is room for up to 999 lines, followed by
a space; if the file exceeds that length, it is probably difficult to
work with, because it's hard to keep that much in working memory.
- Allows for up to three levels of nesting for e-mail quoting (">>> "). I
really hope more than that is not needed. If it is, modern editors can
easily reflow text (e.g. `gq' in vim).
This is particularily valuable for various scripts that perform manipulation
on buffers, as unloading a buffer not only requires saving, but discards
modification history for undos.
Mike Gerwitz