feat: Add column_count, row_count and is_empty methods

[Techassi]

This PR adds three methods:

• column_count: Returns the number of columns in the table
• row_count: Returns the number of rows in the table
• is_empty: Returns if the table is empty (contains no data rows)

[codecov-commenter]

Codecov Report

Merging #119 (044cf03) into main (675125a) will decrease coverage by 0.16%.
Report is 2 commits behind head on main.
The diff coverage is 100.00%.

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@@            Coverage Diff             @@
##             main     #119      +/-   ##
==========================================
- Coverage   96.52%   96.36%   -0.16%     
==========================================
  Files          19       18       -1     
  Lines        1754     1763       +9     
==========================================
+ Hits         1693     1699       +6     
- Misses         61       64       +3     

Files Changed	Coverage Δ
src/table.rs	85.59% <100.00%> (+0.70%)	⬆️

... and 2 files with indirect coverage changes

[Nukesor]

Thanks for your contribution!

I'm currently on holiday until next week and won't be able to review your PR until then :)

[Nukesor]

I actually want to challenge the addition of the _count methods.

I'm not sure if this is particularily useful, since the alternative .row_iter().count() and .column_iter().count() really isn't that much longer and more complex.
I don't see the benefit of adding this yet.

Regarding the is_empty() call; I'm a bit more inclined to do this, since the alternative would be row_iter().next().is_none(), which isn't ergonomic at all.

But I want to ponder for a moment on what an empty table actually is?
Is it a table without rows?
What if there's a header?
What if there're rows, but the rows don't have any cells?

Personally I'm not sure which of these conditions should be met for a table to be considered empty.

[Techassi]

I actually want to challenge the addition of the _count methods.

I'm not sure if this is particularily useful, since the alternative .row_iter().count() and .column_iter().count() really isn't that much longer and more complex.
I don't see the benefit of adding this yet.

The current implementation avoids constructing an iterator which is then immediately consumed by the .count() call.

But I want to ponder for a moment on what an empty table actually is?
Is it a table without rows?
What if there's a header?
What if there're rows, but the rows don't have any cells?

Yes I was thinking about the same stuff you did. Currently I consider the table to be empty if there are no data rows. This excludes the header. A header being there without any data rows is still considered empty.

We could expand this implementation and also check if the rows contain cells, and if they don't, the table will be empty.

[Techassi]

Any update on this? @Nukesor

[Nukesor]

I guess these changes are fine :)

The argument of "a table is empty if no data rows are in it" seems reasonable as well.

Thanks for the contribution!