From: Jeff King <peff@peff.net>
To: phillip.wood@dunelm.org.uk
Cc: Ryan Zoeller <rtzoeller@rtzoeller.com>,
Junio C Hamano <gitster@pobox.com>,
git@vger.kernel.org
Subject: Re: [RFC 0/1] Leading whitespace as a function identification heuristic?
Date: Fri, 25 Sep 2020 14:43:19 -0400 [thread overview]
Message-ID: <20200925184319.GA660343@coredump.intra.peff.net> (raw)
In-Reply-To: <1c03faa0-011c-39c2-acb6-d09a5fcfc818@gmail.com>
On Fri, Sep 25, 2020 at 10:11:33AM +0100, Phillip Wood wrote:
> If I've understood correctly when ...code 2... contains changes that are
> themselves indented then we'll pick the wrong function header for example
>
> void foo() {
> void bar() {
> ...code 1...
> }
> for (...) {
> // if this line is changed we pick bar rather
> // than foo because it is the first function
> // header with a smaller indentation than the
> // first changed line.
> }
> }
>
> Unfortunately I suspect code like that is not uncommon and the diff would
> regress with this simple heuristic. It might be possible to recalculate the
> required indentation as we walk backwards up the file though, so when we hit
> the "for" line we reduce the maximum indentation allowed for a match and so
> skip "bar" as a function header.
Thanks, that's a great counter-example I hadn't considered.
Yes, I agree that adjusting the desired indentation as we walk backwards
would work. That's assuming indentation is hierarchical, but I think
that's implied by the existence of this feature at all.
Another possible corner case: tabs vs spaces. If I have:
<space><space><space><space><space><space><space><space>foo
<tab><tab>bar
which is more indented? Counting isspace(), it is the first one. But
visually, it would _usually_ be the second one. But of course it would
depend on your tabstops.
The above example is obviously stupid and contrived, but I wonder if
there are legitimate confusing cases where people mix tabs and spaces
(e.g., mixed tabs and spaces to align function parameters, etc).
-Peff
next prev parent reply other threads:[~2020-09-25 18:43 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-23 21:59 [RFC 0/1] Leading whitespace as a function identification heuristic? Ryan Zoeller
2020-09-23 21:59 ` [RFC 1/1] xdiff: use leading whitespace in function heuristic Ryan Zoeller
2020-09-24 6:45 ` [RFC 0/1] Leading whitespace as a function identification heuristic? Junio C Hamano
2020-09-24 21:17 ` Jeff King
2020-09-24 22:01 ` Ryan Zoeller
2020-09-25 9:11 ` Phillip Wood
2020-09-25 18:43 ` Jeff King [this message]
2020-09-25 19:01 ` Phillip Wood
2020-09-25 19:05 ` Jeff King
2020-09-25 18:12 ` Johannes Sixt
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