Get the intersection of list of array

https://docs.appian.com/suite/help/22.3/fnc_set_intersection.html

Hi Stefan,

I have tried intersection with reduce function but not able to achieve it as list of number array generate at runtime and I am not able to pass it like an arguments.

[{1,2,3},{2,3,4},{4,5,6}]

Thanks 

Manish

Why do you need reduce to do that?

intersection({1,2,3,4},{2,3,4},{4,5,6})

returns 4, which is the only number present in all the arrays.

The list of Array generates at run time , How will I pass the list of array to intersection function ? , So I tried to used the reduce function to send the result of intersection  for next iteration(interaction).

Manish_Kumar said:

generates at run time

Can you clarify what you mean by this?  What's the underlying code here?

a!localVariables(
  local!arrays: a!forEach(
    items: enumerate(1 + rand() * 10),
    expression: a!map(
      list: 1 + enumerate(rand() * 10)
    )
  ),
  reduce(
    rule!SSH_Intersect(a:_, b:_),
    local!arrays[1],
    ldrop(local!arrays, 1)
  )
)

rule!SSH_Intersect(a (map), b(map))
a!map(
  list: intersection(ri!a.list, ri!b.list)
)

Using just arrays does not work. I assume there is some undefined/weird behaviour inside reduce when feeding it with lists of lists.

a!localVariables(
  local!arrays: a!forEach(
    items: enumerate(1 + rand() * 10),
    expression: a!map(
      list: 1 + enumerate(rand() * 10)
    )
  ),
  reduce(
    rule!SSH_Intersect(a:_, b:_),
    local!arrays[1],
    ldrop(local!arrays, 1)
  )
)

rule!SSH_Intersect(a (map), b(map))
a!map(
  list: intersection(ri!a.list, ri!b.list)
)

Using just arrays does not work. I assume there is some undefined/weird behaviour inside reduce when feeding it with lists of lists.

Unknown said:

lists of lists

come on - you should already know that appian almost completely refuses to nicely handle lists-of-lists in the first place ;-)

True, still hoping .... The weird thing is, that, using just lists, it works sometimes, and sometimes it throws a weird error message.

Thanks everyone for your inputs.