Behavior of unlist on nested lists

[lwaldron]

Is these differences with base::unlist() intentional? 1) names of vector, 2) behavior on nested lists.

suppressPackageStartupMessages(library(S4Vectors))

# both return numeric, although with different names
base::unlist(list(a=1, b=2:1))
#>  a b1 b2 
#>  1  2  1
BiocGenerics::unlist(SimpleList(a=1, b=2:1))
#> a b b 
#> 1 2 1

# returns numeric
base::unlist(list(a=1, b=list(2:1)))
#>  a b1 b2 
#>  1  2  1
# returns class "base::list" containing an `IntegerList` element
BiocGenerics::unlist(List(a=1, b=List(2:1)))
#> $a
#> [1] 1
#> 
#> $b
#> List of length 1

sessionInfo()
#> R Under development (unstable) (2019-01-26 r76018)
#> Platform: x86_64-pc-linux-gnu (64-bit)
#> Running under: Debian GNU/Linux 9 (stretch)
#> 
#> Matrix products: default
#> BLAS/LAPACK: /usr/lib/libopenblasp-r0.2.19.so
#> 
#> locale:
#>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
#>  [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
#>  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=C             
#>  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
#>  [9] LC_ADDRESS=C               LC_TELEPHONE=C            
#> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
#> 
#> attached base packages:
#> [1] parallel  stats4    stats     graphics  grDevices utils     datasets 
#> [8] methods   base     
#> 
#> other attached packages:
#> [1] S4Vectors_0.21.10   BiocGenerics_0.29.1
#> 
#> loaded via a namespace (and not attached):
#>  [1] Rcpp_1.0.0      digest_0.6.18   magrittr_1.5    evaluate_0.13  
#>  [5] highr_0.7       stringi_1.3.1   rmarkdown_1.11  tools_3.6.0    
#>  [9] stringr_1.4.0   xfun_0.5        yaml_2.2.0      compiler_3.6.0 
#> [13] htmltools_0.3.6 knitr_1.21

^{Created on 2019-02-24 by the reprex package (v0.2.1)}

[hpages]

The 1st one is intentional (the name mangling preformed by base::unlist() is insane so we got rid of it).

The 2nd one is not. We didn't implement recursive unlisting for List derivatives yet. I'll take care of it.

[LTLA]

Just encountered this. It seems as if it would be fairly simple to fix with the following prototype code:

# In unlist,List-method:
    if (length(dim(xx[[1L]])) < 2L) {
        if (recursive) { 
            xx <- lapply(xx, unlist, recursive=TRUE, use.names=use.names)
        }
        unlisted_x <- do.call(c, xx)
    } else { 
# ... and so on