terraform {
  experiments = [
    variable_validation
  ]
}

variable "a" {
  validation {
    condition = can(regex("foo|aze|qsd", var.a))
    error_message = "Valid values are foo, aze, qsd."
  }
}
variable "b" {
  default = "test"
}
variable "c" {
  type = list
  default = ["foo", "bar", "baz"]
}
variable "d" {
  type = map
  default = {
    "foo" = "bar"
    "aze" = "rty"
    "qsd" = "fgh"
  }
}

output "ov1" {
  value = "${var.a}"
}
output "ov2" {
  value = "${var.b}"
}
output "ov3" {
  value = "${var.c[2]}"
}
output "ov4" {
  value = "${var.d}"
}
output "ov4_foo" {
  value = "${var.d.foo}"
}

output "ov4_lookup" {
  value = "${lookup(var.d, var.a)}"
}