Optimize wk_coords() for xy

[paleolimbot]

Closes #138; although, this doesn't change any sf-related code. Because the st_coordinates() objects are matrices, multiple copies are needed to return the object that wk_coords needs (a data frame). It is about 2x faster to do this, but the existing route wasn't all that slow to begin with and the copies require about 3x the memory.

I did keep the optimization for xy that came about as part of this, though, since that's about 3x faster if there are no empties and 2x faster if there are.

library(wk)

points <- xy(runif(1e6), runif(1e6))
bench::mark(
  wk::wk_coords(points),
  wk:::wk_coords.default(points)
)
#> # A tibble: 2 × 6
#>   expression                          min   median `itr/sec` mem_alloc `gc/sec`
#>   <bch:expr>                     <bch:tm> <bch:tm>     <dbl> <bch:byt>    <dbl>
#> 1 wk::wk_coords(points)            4.88ms   5.57ms     179.     19.1MB     179.
#> 2 wk:::wk_coords.default(points)  16.75ms  16.96ms      58.9    26.8MB     168.

points_with_empty <- points
points_with_empty[100] <- xy(NA, NA)
bench::mark(
  wk::wk_coords(points_with_empty),
  wk:::wk_coords.default(points_with_empty)
)
#> # A tibble: 2 × 6
#>   expression                                     min  median `itr/sec` mem_alloc
#>   <bch:expr>                                <bch:tm> <bch:t>     <dbl> <bch:byt>
#> 1 wk::wk_coords(points_with_empty)            11.4ms  11.6ms      86.6    61.1MB
#> 2 wk:::wk_coords.default(points_with_empty)   18.2ms  18.4ms      54.0    53.4MB
#> # … with 1 more variable: `gc/sec` <dbl>

[codecov-commenter]

Codecov Report

Base: 99.03% // Head: 99.04% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (02aaaf9) compared to base (7c86afb).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #160   +/-   ##
=======================================
  Coverage   99.03%   99.04%           
=======================================
  Files          81       81           
  Lines        5824     5837   +13     
=======================================
+ Hits         5768     5781   +13     
  Misses         56       56           

Impacted Files	Coverage Δ
R/vertex-filter.R	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.