One-line show for SparseVector

[jishnub]

Fix #400 by implementing the suggestion in #400 (comment).

After this,

julia> S = sparsevec([1,4], [2,3])
4-element SparseVector{Int64, Int64} with 2 stored entries:
  [1]  =  2
  [4]  =  3

julia> show(S)
sparsevec([1, 4], [2, 3], 4)
julia> [S,S]
2-element Vector{SparseVector{Int64, Int64}}:
 sparsevec([1, 4], [2, 3], 4)
 sparsevec([1, 4], [2, 3], 4)

The displayed form is round-trippable as well.

[codecov]

Codecov Report

Merging #427 (9e68b7e) into main (e86b148) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #427      +/-   ##
==========================================
+ Coverage   85.40%   85.43%   +0.03%     
==========================================
  Files          13       13              
  Lines        8734     8733       -1     
==========================================
+ Hits         7459     7461       +2     
+ Misses       1275     1272       -3     

Files	Coverage Δ
src/sparsevector.jl	95.64% <100.00%> (+0.21%)	⬆️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[matbesancon]

@jishnub fantastic! Some docstrings need fixing now that the printing changed: https://github.com/JuliaSparse/SparseArrays.jl/actions/runs/5985741971/job/16238147916?pr=427

Also, we should probably add some tests beyond the undef one you changed

[jishnub]

Updated, and added tests. I think this works now. This doesn't change the display for arrays with zero elements:

julia> S = sparsevec(Int64[], Int64[], 3)
3-element SparseVector{Int64, Int64} with 0 stored entries

julia> [S]
1-element Vector{SparseVector{Int64, Int64}}:
 3-element SparseVector{Int64, Int64} with 0 stored entries

julia> show(S)
sparsevec(Int64[], Int64[], 3)

The difference arises as the display of S has only one line even in "text/plain", which makes [S] use it directly instead of using show(S) as in non-empty cases. I'm unsure what's the best way to address this, so I've left this unchanged for now (and this doesn't matter for the original issue)

[matbesancon]

The difference arises as the display of S has only one line even in "text/plain", which makes [S] use it directly instead of using show(S) as in non-empty cases. I'm unsure what's the best way to address this, so I've left this unchanged for now (and this doesn't matter for the original issue)

@jishnub I believe it would make sense to also cover this case but this can be done in a separate issue, can you create one?

[matbesancon]

In the meantime, we can merge this, thanks a lot!

[dkarrasch]

@matbesancon Please be careful about the merge option. This should have better been squashed and merged. For next time. 😉

[matbesancon]

Oh my bad! I usually do, it slipped here