Terraform list-in/list-out operational

list.tf

module "example1" {
  source = "./list"
}
module "example2" {
  source = "./list"
  values = ["this", "that", "other"]
}
module "example3" {
  source = "./list"
  values = ["${module.example2.many}"]
}
module "example4" {
  source = "./list"
  values = ["${module.example2.many}", "extra"]
}

list_output.tf

output "many" {
  value = ["${var.values}"]
}

list_variables.tf

variable "values" {
  type = "list"
  default = ["first", "second", "third"]
}

output.tf

output "example1_vals" {
  value = ["${module.example1.many}"]
}
output "example2_vals" {
  value = ["${module.example2.many}"]
}
output "example3_vals" {
  value = ["${module.example3.many}"]
}
output "example4_vals" {
  value = ["${module.example4.many}"]
}

terraform_apply_output.txt

Apply complete! Resources: 0 added, 0 changed, 0 destroyed.
Releasing state lock. This may take a few moments...

Outputs:

example1_vals = [
    first,
    second,
    third
]
example2_vals = [
    this,
    that,
    other
]
example3_vals = [
    this,
    that,
    other
]
example4_vals = [
    this,
    that,
    other,
    extra
]

To compensate for lack of subdirs in gists, after pulling:

mkdir list
mv list_output.tf list/output.tf
mv list_variables.tf list/variables.tf
terraform apply