Efficiency: promises method

[shikokuchuo]

In our poller, we can replace a usage of tryCatch() with withCallingHandlers(), as we just need to enact a side-effect and let the error percolate up to a tryCatch already established within promises::promise() from where it's called.

There's always a benefit to avoiding tryCatch:

bench::mark(
  withCallingHandlers({}, error = identity),
  tryCatch({}, error = identity)
)
#> # A tibble: 2 × 6
#>   expression                            min  median `itr/sec` mem_alloc `gc/sec`
#>   <bch:expr>                       <bch:tm> <bch:t>     <dbl> <bch:byt>    <dbl>
#> 1 withCallingHandlers({ }, error …    410ns   492ns  1572514.        0B    157. 
#> 2 tryCatch({ }, error = identity)    1.35µs   1.6µs   605433.        0B     60.5

^{Created on 2025-10-24 with reprex v2.1.1}