Re: [PATCHv3 4/4] builtin/blame: highlight recently changed lines

[Stefan Beller <sbeller@google.com>]

On Mon, Jan 8, 2018 at 11:56 AM, Junio C Hamano <gitster@pobox.com> wrote:
> Stefan Beller <sbeller@google.com> writes:
>
>> +static struct color_field {
>> +     timestamp_t hop;
>> +     char col[COLOR_MAXLEN];
>> +} *colorfield;
>> +static int colorfield_nr, colorfield_alloc;
>> +
>> +static void parse_color_fields(const char *s)
>> +{
>> +     struct string_list l = STRING_LIST_INIT_DUP;
>> +     struct string_list_item *item;
>> +     enum { EXPECT_DATE, EXPECT_COLOR } next = EXPECT_COLOR;
>> +
>> +     /* Ideally this would be stripped and split at the same time? */
>> +     string_list_split(&l, s, ',', -1);
>> +     ALLOC_GROW(colorfield, colorfield_nr + 1, colorfield_alloc);
>> +
>> +     for_each_string_list_item(item, &l) {
>> +             switch (next) {
>> +             case EXPECT_DATE:
>> +                     colorfield[colorfield_nr].hop = approxidate(item->string);
>> +                     next = EXPECT_COLOR;
>> +                     colorfield_nr++;
>> +                     ALLOC_GROW(colorfield, colorfield_nr + 1, colorfield_alloc);
>> +                     break;
>
> This should make sure cf[i].hop is monotonically increasing to avoid
> end-user mistakes, I would think (what's 'hop' by the way?).
>
>> +             case EXPECT_COLOR:
>> +                     if (color_parse(item->string, colorfield[colorfield_nr].col))
>> +                             die(_("expecting a color: %s"), item->string);
>
> When you have a typo in one of your configuration files, say "[color
> "blame"] highlightrecent = 1,week,blue,...", you'd want to see a bit
> more than just "expecting a color: week" to help you diagnose and
> resolve the issue.  Giving the name of the variable and the file the
> wrong definition was found in would be needed, givin that this is
> called from the config callback git_blame_config() below.
>
>> +                     next = EXPECT_DATE;
>> +                     break;
>> +             }
>> +     }
>> +
>> +     if (next == EXPECT_COLOR)
>> +             die (_("must end with a color"));
>
> Same here.
>
>>               OPT_BIT(0, "color-lines", &output_option, N_("color redundant metadata from previous line differently"), OUTPUT_COLOR_LINE),
>>               OPT_BIT(0, "color-fields", &output_option, N_("color redundant metadata fields from previous line differently"), OUTPUT_COLOR_FIELDS),
>> +             OPT_BIT(0, "heated-lines", &output_option, N_("color lines by age"), OUTPUT_HEATED_LINES),
>
> These options may be useful while having fun experimenting, but my
> gut feeling is that these are too fine-grained for end-users to
> tweak per invocation basis (which is what command line options are
> for).
>
> But perhaps I am biased (as anybody else), as personally I find
> anything beyond step 2/4 uninteresting, and not adding too many of
> these options is consistent with that viewpoint ;-)

See, I find 2 and 3 uninteresting and just did it 'because someone else
hinted at that is what they want'. Maybe I was a bad listener.

4 (maybe with 2 in combination) would be all I need as that allows me
to quickly judge the trustworthiness of code (old code is better,
just like most liquors? ;)

> In any case, thanks for a fun read.

Thanks, I'll reread the comments and see if I can remove some
options to make it useful for upstream consumption.

Thanks,
Stefan