Combine/merge lists by elements names (list in list)

Question

I have two lists, whose elements have partially overlapping names, which I need to merge/combine together into a single list, element by element:

My question is rela

Answer 1

You can use lapply operating on the keys to do this merge:

keys <- unique(c(names(l.1), names(l.2)))
setNames(lapply(keys, function(key) list(c(l.1[[key]][[1]], l.2[[key]][[1]]),
                                         c(l.1[[key]][[2]], l.2[[key]][[2]]))),
         keys)
# $a
# $a[[1]]
# [1] 10 20
# 
# $a[[2]]
# [1] 1 0
# 
# $b
# $b[[1]]
# [1] 10 20 30
# 
# $b[[2]]
# [1] 1 2 3
# 
# $c
# $c[[1]]
# [1]  9 12 13
# 
# $c[[2]]
# NULL