tuple.jl

function f(cols)
    x = 0.0
    for i in 1:length(cols[1])
        t = ntuple(j -> cols[j][i], length(cols))
        x += t[1]
    end
    x
end

function g(cols, names)
    x = 0.0
    for i in 1:length(cols[1])
        t = ntuple(j -> cols[j][i], length(cols))
        nt = NamedTuple{names,typeof(t)}(t)
        x += nt.x
    end
    x
end

using DataFrames
df = DataFrame(x=rand(1000), y=rand(1000))
df2 = DataFrame(rand(1000, 100))
df2.x = rand(1000)

f(tuple(DataFrames.columns(df)...))
f(tuple(DataFrames.columns(df2)...))

g(tuple(DataFrames.columns(df)...), tuple(names(df)...))
g(tuple(DataFrames.columns(df2)...), tuple(names(df2)...))