Re: [PATCH v5 01/12] doc: use 'symmetric difference' consistently
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Aug 26, 2016, 16:09 UTC
- Message-ID
- <xmqq60qnjyuo.fsf@gitster.mtv.corp.google.com>
- In-Reply-To
- <eca8d854-9483-ea30-c5a8-71a35c3ca7bd@gmail.com>
Jakub Narębski <jnareb@gmail.com> writes:
Show 11 quoted lines
>> --left-right:: >> - Mark which side of a symmetric diff a commit is reachable from. >> + Mark which side of a symmetric difference a commit is reachable from. >> Commits from the left side are prefixed with `<` and those from >> the right with `>`. If combined with `--boundary`, those >> commits are prefixed with `-`. > > That's very nice that two^W three related options, namely --left-only, > --right-only and --left-right now use the same notation. > > I guess that "symmetric range" was to mean "symmetric difference range".
By "symmetric difference", we mean a "set difference" operation that is symmetric. Contrasting with asymmetric difference that gives a set of elements that belong to set A but do not belong to set B (i.e. B..A), symmetric difference of set A and set B gives a set of elements that belong to either set A alone or set B alone but not both (i.e. A...B).
So if you really want a fully spelled name, we would not want to call it with a name with "range". It is "symmetric set difference", and "symmetric difference" in the updated sentence is a short-hand for that.