Re: [PATCH 7/7] diff.c: add --color-moved-ignore-space-delta option
- From
Stefan Beller <sbeller@google.com>
- Date
- Apr 3, 2018, 19:22 UTC
- Message-ID
- <CAGZ79kYPx=OB92yWFw8W=zJDoJT5BjBd3Q+gt_WS_KuUw299vQ@mail.gmail.com>
- In-Reply-To
- <20180402174118.d204ec0d4b9d2fa7ebd77739@google.com>
On Mon, Apr 2, 2018 at 5:41 PM, Jonathan Tan <jonathantanmy@google.com> wrote:
Show 13 quoted lines
> On Mon, 2 Apr 2018 15:48:54 -0700
> Stefan Beller <sbeller@google.com> wrote:
>
>> +struct ws_delta {
>> + int deltachars;
>> + char firstchar;
>> +};
>
> I'll just make some overall design comments.
>
> Shouldn't this be a string of characters (or a char* and len) and
> whether it was added or removed? If you're only checking the first
> character, this would not work if the other characters were different.I considered diving into this, but it seemed to be too complicated for
>95 % of the use cases, which can be approximated in change of the
first character.
Because if we take a string of characters, we'd also need to take care of tricky conversions (e.g. Are 8 white spaces equal to a tab, and if so do we break blocks if one line converts 8 ws to a tab?)
So I would definitely pursue the string instead of change of first character, but what are all the heuristics to put in?
Just to be clear: The string would contain only the change in white space up front, or would we also somehow store white space in other parts?
- # This is a sample comment - # across multiple lines - # maybe even a license header + # This is a sample comment + # across multiple lines + # maybe even a license header
How about this?
Show 25 quoted lines
> >> @@ -717,10 +752,20 @@ static int moved_entry_cmp(const void *hashmap_cmp_fn_data, >> const struct diff_options *diffopt = hashmap_cmp_fn_data; >> const struct moved_entry *a = entry; >> const struct moved_entry *b = entry_or_key; >> + unsigned flags = diffopt->color_moved & XDF_WHITESPACE_FLAGS; >> + >> + if (diffopt->color_moved & COLOR_MOVED_DELTA_WHITESPACES) >> + /* >> + * As there is not specific white space config given, >> + * we'd need to check for a new block, so ignore all >> + * white space. The setup of the white space >> + * configuration for the next block is done else where >> + */ >> + flags |= XDF_IGNORE_WHITESPACE; >> >> return !xdiff_compare_lines(a->es->line, a->es->len, >> b->es->line, b->es->len, >> - diffopt->color_moved & XDF_WHITESPACE_FLAGS); >> + flags); >> } > > I think we should just prohibit combining this with any of the > whitespace ignoring flags except for the space-at-eol one. They seem to > contradict anyway.
ok, we can narrow this one down to ignore all white space.
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> >> +test_expect_success 'compare whitespace delta across moved blocks' ' >> + >> + git reset --hard && >> + q_to_tab <<-\EOF >text.txt && >> + QIndented >> + QText >> + Qacross >> + Qfive >> + Qlines >> + QBut! >> + Qthis >> + QQone >> + Qline >> + QQdid >> + Qnot >> + QQadjust >> + EOF > > Do we need 5 lines? I thought 2 would suffice. (It's the ALNUM_COUNT > that matters, as far as I know.) This makes it hard to see that the > "But!" line is the one that counts.
I did not want to go with the bare minimum as then adjusting the minimum would be a pain as these unrelated (to the minimum) test cases would break.
> >> +test_expect_success 'compare whitespace delta across moved blocks with multiple indentation levels' '
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>> + EOF > > If the objective it just to show that the functions f and g are treated > as one unit despite their lines being of multiple indentation levels, > the test file could be much shorter.
yeah, I noticed that we already test that in the test above where we have that test after the "But!", where lines ziggy-zag. Will drop this test.