unname() doesn't restore the matrixClass of my DelayedOps subclass

[LTLA]

Another side-effect from #119 - unname() doesn't restore the matrixClass of my ReloadedArray:

library(alabaster.base)
arr <- array(rpois(260, 10), c(26, 10))
dir <- tempfile()
saveObject(arr, dir)

obj <- readArray(dir)
library(DelayedArray)
showtree(obj)
## 26x10 integer: ReloadedMatrix object
## └─ 26x10 integer: ReloadedArraySeed object
##    └─ 26x10 integer: Stack of 1 unary iso op(s)
##       └─ 26x10 raw: [seed] HDF5ArraySeed object

rownames(obj) <- LETTERS
showtree(obj)
## 26x10 integer: DelayedMatrix object
## └─ 26x10 integer: Set dimnames
##    └─ 26x10 integer: ReloadedArraySeed object
##       └─ 26x10 integer: Stack of 1 unary iso op(s)
##          └─ 26x10 raw: [seed] HDF5ArraySeed object

obj <- unname(obj)
showtree(obj)
## 26x10 integer: DelayedMatrix object
## └─ 26x10 integer: ReloadedArraySeed object
##    └─ 26x10 integer: Stack of 1 unary iso op(s)
##       └─ 26x10 raw: [seed] HDF5ArraySeed object

You can see after the unnaming, I don't recover my ReloadedMatrix class, which has some consequences for correct dispatch (e.g., see broken celldex build).

The root cause is the DelayedArray,DelayedOps-method. This first simplifies the seed to remove the opposing dimnames operations, leaving a ReloadedArraySeed, so far so good. However, because ReloadedArraySeed now inherits from DelayedOps, the code decides to call the new_DelayedArray() function instead of DelayedArray(). This bypasses my DelayedArray method for ReloadedArraySeed, leading to the incorrect class being returned.

I can see that the if condition is necessary to avoid infinite recursion, so a "simple" fix might be to check whether a DelayedArray method exists for the seed that is not the DelayedOps method:

# seed is simplified at this point.
FUN <- selectMethod("DelayedArray", class(seed))
if (FUN@defined@.Data != "DelayedOps") {
   return(FUN(seed))
}

Or some kind of logic like that.

Session information

R Under development (unstable) (2024-10-31 r87278)
Platform: x86_64-pc-linux-gnu
Running under: Ubuntu 22.04.5 LTS

Matrix products: default
BLAS:   /home/luna/Software/R/trunk/lib/libRblas.so 
LAPACK: /home/luna/Software/R/trunk/lib/libRlapack.so;  LAPACK version 3.12.0

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=en_US.UTF-8   
 [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       

time zone: America/Los_Angeles
tzcode source: system (glibc)

attached base packages:
[1] stats4    stats     graphics  grDevices utils     datasets  methods  
[8] base     

other attached packages:
 [1] alabaster.matrix_1.7.4 alabaster.base_1.7.2   HDF5Array_1.35.2      
 [4] rhdf5_2.51.1           DelayedArray_0.33.3    SparseArray_1.7.2     
 [7] S4Arrays_1.7.1         IRanges_2.41.2         abind_1.4-8           
[10] S4Vectors_0.45.2       MatrixGenerics_1.19.0  matrixStats_1.4.1     
[13] BiocGenerics_0.53.3    generics_0.1.3         Matrix_1.7-1          

loaded via a namespace (and not attached):
 [1] zlibbioc_1.53.0         lattice_0.22-6          rhdf5filters_1.19.0    
 [4] XVector_0.47.0          Rhdf5lib_1.29.0         grid_4.5.0             
 [7] compiler_4.5.0          tools_4.5.0             alabaster.schemas_1.7.0
[10] Rcpp_1.0.13-1           jsonlite_1.8.9          crayon_1.5.3