Don't print "with more rows" if result set contains exactly 10 rows

[krlmlr]

dbplyr::memdb_frame(a = 1:10)
#> # Source:   table<wrcfejsauq> [?? x 1]
#> # Database: sqlite 3.19.3 [:memory:]
#>        a
#>    <int>
#>  1     1
#>  2     2
#>  3     3
#>  4     4
#>  5     5
#>  6     6
#>  7     7
#>  8     8
#>  9     9
#> 10    10
#> # ... with more rows

Created on 2018-01-19 by the reprex package (v0.1.1.9000).

We could fetch 21 rows instead of 10, to make sure we're consistent with the behavior for data frames (to display the first 20 rows if the result has 20 rows or less). If we get 20 or less, we display. If we get 21, we display the first 10 and show "with at least 11 more rows".

[krlmlr]

Postponing, because output might change results of revdepchecks.

[stefanedwards]

Adding on top of this, using print(..., n=-1) we can get all rows printed, but print.tbl still outputs a "... with xx more rows":

Note, mtcars contains 32 rows:

print(as_tibble(mtcars))
# A tibble: 32 x 11
     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
 * <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
 1  21.0    6.  160.  110.  3.90  2.62  16.5    0.    1.    4.    4.
 2  21.0    6.  160.  110.  3.90  2.88  17.0    0.    1.    4.    4.
 3  22.8    4.  108.   93.  3.85  2.32  18.6    1.    1.    4.    1.
 4  21.4    6.  258.  110.  3.08  3.22  19.4    1.    0.    3.    1.
 5  18.7    8.  360.  175.  3.15  3.44  17.0    0.    0.    3.    2.
 6  18.1    6.  225.  105.  2.76  3.46  20.2    1.    0.    3.    1.
 7  14.3    8.  360.  245.  3.21  3.57  15.8    0.    0.    3.    4.
 8  24.4    4.  147.   62.  3.69  3.19  20.0    1.    0.    4.    2.
 9  22.8    4.  141.   95.  3.92  3.15  22.9    1.    0.    4.    2.
10  19.2    6.  168.  123.  3.92  3.44  18.3    1.    0.    4.    4.
# ... with 22 more rows

This time, forcing all rows printed:

print(as_tibble(mtcars), n=-1)
# A tibble: 32 x 11
     mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
 * <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
 1  21.0    6. 160.   110.  3.90  2.62  16.5    0.    1.    4.    4.
 2  21.0    6. 160.   110.  3.90  2.88  17.0    0.    1.    4.    4.
 3  22.8    4. 108.    93.  3.85  2.32  18.6    1.    1.    4.    1.
 4  21.4    6. 258.   110.  3.08  3.22  19.4    1.    0.    3.    1.
 5  18.7    8. 360.   175.  3.15  3.44  17.0    0.    0.    3.    2.
 6  18.1    6. 225.   105.  2.76  3.46  20.2    1.    0.    3.    1.
 7  14.3    8. 360.   245.  3.21  3.57  15.8    0.    0.    3.    4.
 8  24.4    4. 147.    62.  3.69  3.19  20.0    1.    0.    4.    2.
 9  22.8    4. 141.    95.  3.92  3.15  22.9    1.    0.    4.    2.
10  19.2    6. 168.   123.  3.92  3.44  18.3    1.    0.    4.    4.
11  17.8    6. 168.   123.  3.92  3.44  18.9    1.    0.    4.    4.
12  16.4    8. 276.   180.  3.07  4.07  17.4    0.    0.    3.    3.
13  17.3    8. 276.   180.  3.07  3.73  17.6    0.    0.    3.    3.
14  15.2    8. 276.   180.  3.07  3.78  18.0    0.    0.    3.    3.
15  10.4    8. 472.   205.  2.93  5.25  18.0    0.    0.    3.    4.
16  10.4    8. 460.   215.  3.00  5.42  17.8    0.    0.    3.    4.
17  14.7    8. 440.   230.  3.23  5.34  17.4    0.    0.    3.    4.
18  32.4    4.  78.7   66.  4.08  2.20  19.5    1.    1.    4.    1.
19  30.4    4.  75.7   52.  4.93  1.62  18.5    1.    1.    4.    2.
20  33.9    4.  71.1   65.  4.22  1.84  19.9    1.    1.    4.    1.
21  21.5    4. 120.    97.  3.70  2.46  20.0    1.    0.    3.    1.
22  15.5    8. 318.   150.  2.76  3.52  16.9    0.    0.    3.    2.
23  15.2    8. 304.   150.  3.15  3.44  17.3    0.    0.    3.    2.
24  13.3    8. 350.   245.  3.73  3.84  15.4    0.    0.    3.    4.
25  19.2    8. 400.   175.  3.08  3.84  17.0    0.    0.    3.    2.
26  27.3    4.  79.0   66.  4.08  1.94  18.9    1.    1.    4.    1.
27  26.0    4. 120.    91.  4.43  2.14  16.7    0.    1.    5.    2.
28  30.4    4.  95.1  113.  3.77  1.51  16.9    1.    1.    5.    2.
29  15.8    8. 351.   264.  4.22  3.17  14.5    0.    1.    5.    4.
30  19.7    6. 145.   175.  3.62  2.77  15.5    0.    1.    5.    6.
31  15.0    8. 301.   335.  3.54  3.57  14.6    0.    1.    5.    8.
# ... with 33 more rows

I'd say n=-1 works in line with base read.table and such to not have an upper limit. So it makes good sense to keep it like this.

[krlmlr]

Unfortunately, n = -1 is just passed to head(), this means that 31 out of 32 rows are printed. Thanks for spotting this problem.

I don't like the idea of supporting -1 as a shortcut for "everything", we can already use n = Inf for this.

[stefanedwards]

Oh no, I'm an idiot who cannot count to 32 (!). I am just used to start counting at 0, so I did not see that n=-1 left the last entry out...

I agree, n = Inf works better and does not in this case print that there are more rows. Fun fact, using n =-31 will print that there are 63 more rows.

I think that's all from me for now.

[krlmlr]

Thanks for the heads-up, and again for filing the issue!

[github-actions]

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