Loops for unknown numbers of inputs

General Usage
11

I’m not sure I fully understand your doubt, but the script, which is certainly not as efficient as the other proposals, should work for a generic number of input vectors.

julia> as = [1,2]
2-element Vector{Int64}:
 1
 2

julia> bs = (3,4, 5)
(3, 4, 5)

julia> cs = [6]
1-element Vector{Int64}:
 6

julia> ds = [7, 8, 9]
3-element Vector{Int64}:
 7
 8
 9

julia> ads=[as,bs,cs,ds]
4-element Vector{Any}:
 [1, 2]
 (3, 4, 5)
 [6]
 [7, 8, 9]

julia> reduce(hmprod, ads)
18-element Vector{Any}:
 (1, 3, 6, 7)
 (1, 3, 6, 8)
 (1, 3, 6, 9)
 (1, 4, 6, 7)
 (1, 4, 6, 8)
 (1, 4, 6, 9)
 (1, 5, 6, 7)
 (1, 5, 6, 8)
 (1, 5, 6, 9)
 (2, 3, 6, 7)
 (2, 3, 6, 8)
 (2, 3, 6, 9)
 (2, 4, 6, 7)
 (2, 4, 6, 8)
 (2, 4, 6, 9)
 (2, 5, 6, 7)
 (2, 5, 6, 8)
 (2, 5, 6, 9)

julia> function hmprod(v...)
           p=[]
           i=1
           for a in v[1], b in v[2]
               push!(p, (a...,b))
               i+=1
           end
               p
           end
hmprod (generic function with 1 method)

I add a recursive version, which does not use functions of either Base or other packages.

julia> function rhmprod(v...)
           p=Tuple[]
           i=1
           if length(v)>=2
               for a in v[1], b in v[2]
                   push!(p, (a...,b))
                   i+=1
               end
               rhmprod(p,v[3:end]...)
           else
               v[1]
           end
       end
rhmprod (generic function with 1 method)

julia> rhmprod(ads...)
18-element Vector{Tuple}:
 (1, 3, 6, 7)
 (1, 3, 6, 8)
 (1, 3, 6, 9)
 (1, 4, 6, 7)
 (1, 4, 6, 8)
 (1, 4, 6, 9)
 (1, 5, 6, 7)
 (1, 5, 6, 8)
 (1, 5, 6, 9)
 (2, 3, 6, 7)
 (2, 3, 6, 8)
 (2, 3, 6, 9)
 (2, 4, 6, 7)
 (2, 4, 6, 8)
 (2, 4, 6, 9)
 (2, 5, 6, 7)
 (2, 5, 6, 8)
 (2, 5, 6, 9)
1 Like