define merge(combine, ::NamedTuple, ...)

[goretkin]

julia> merge(+, Dict(:a=>3,:b=>5), Dict(:a=>4, :c=>6))
Dict{Symbol,Int64} with 3 entries:
  :a => 7
  :b => 5
  :c => 6

julia> merge(+, (a=3,b=5), (a=4,c=6))
ERROR: MethodError: no method matching merge(::typeof(+), ::NamedTuple{(:a, :b),Tuple{Int64,Int64}}, ::NamedTuple{(:a, :c),Tuple{Int64,Int64}})

As far as I can tell, this is simply an omission. Is there a reason to not define this?

[goretkin]

I just noticed that these relevant changes: #34296

[tkf]

Yes, we should implement mergewith(combine, ::NamedTuple, ...) instead of merge(combine::Function, ::NamedTuple, ...).

[cossio]

Why mergewith? Given that merge does just this for Dict, why not use the same name for NamedTuple?

[tkf]

@cossio mergewith and mergewith! for dictionaries are added in Julia 1.5.