gistfile1.txt

variable "foo" {
    default = ["1", "2", "3"]
}

variable "bar" {
    default = ["a", "b"]
}

resource "aws_sns_topic" "test" {
    name = "${element(var.foo, count.index / length(var.bar))}-${element(var.bar, count.index)}"
    count = "${length(var.foo) * length(var.bar)}"
}


resource "aws_sqs_queue" "listeners" {
    name = "${element(var.foo, count.index / length(var.bar))}-${element(var.bar, count.index)}"
    count = "${length(var.foo) * length(var.bar)}"
}


resource "aws_sns_topic_subscription" "sub-foo-to-bar" {
    topic_arn = "${element(aws_sns_topic.test.*.arn)}"
    protocol = "sqs"
    endpoint = "${element(aws_sqs_queue.listeners.*.arn)}"
    raw_message_delivery = true
    count = "${length(var.foo) * length(var.bar)}"
}

gistfile2.txt

+ aws_sns_topic.test.0
    arn:    "<computed>"
    name:   "1-a"
    policy: "<computed>"

+ aws_sns_topic.test.1
    arn:    "<computed>"
    name:   "1-b"
    policy: "<computed>"

+ aws_sns_topic.test.2
    arn:    "<computed>"
    name:   "2-a"
    policy: "<computed>"

+ aws_sns_topic.test.3
    arn:    "<computed>"
    name:   "2-b"
    policy: "<computed>"

+ aws_sns_topic.test.4
    arn:    "<computed>"
    name:   "3-a"
    policy: "<computed>"

+ aws_sns_topic.test.5
    arn:    "<computed>"
    name:   "3-b"
    policy: "<computed>"

+ aws_sns_topic_subscription.sub-foo-to-bar.0
    arn:                             "<computed>"
    confirmation_timeout_in_minutes: "1"
    endpoint:                        "${element(aws_sqs_queue.listeners.*.arn)}"
    endpoint_auto_confirms:          "false"
    protocol:                        "sqs"
    raw_message_delivery:            "true"
    topic_arn:                       "${element(aws_sns_topic.test.*.arn)}"

+ aws_sns_topic_subscription.sub-foo-to-bar.1
    arn:                             "<computed>"
    confirmation_timeout_in_minutes: "1"
    endpoint:                        "${element(aws_sqs_queue.listeners.*.arn)}"
    endpoint_auto_confirms:          "false"
    protocol:                        "sqs"
    raw_message_delivery:            "true"
    topic_arn:                       "${element(aws_sns_topic.test.*.arn)}"

+ aws_sns_topic_subscription.sub-foo-to-bar.2
    arn:                             "<computed>"
    confirmation_timeout_in_minutes: "1"
    endpoint:                        "${element(aws_sqs_queue.listeners.*.arn)}"
    endpoint_auto_confirms:          "false"
    protocol:                        "sqs"
    raw_message_delivery:            "true"
    topic_arn:                       "${element(aws_sns_topic.test.*.arn)}"

+ aws_sns_topic_subscription.sub-foo-to-bar.3
    arn:                             "<computed>"
    confirmation_timeout_in_minutes: "1"
    endpoint:                        "${element(aws_sqs_queue.listeners.*.arn)}"
    endpoint_auto_confirms:          "false"
    protocol:                        "sqs"
    raw_message_delivery:            "true"
    topic_arn:                       "${element(aws_sns_topic.test.*.arn)}"

+ aws_sns_topic_subscription.sub-foo-to-bar.4
    arn:                             "<computed>"
    confirmation_timeout_in_minutes: "1"
    endpoint:                        "${element(aws_sqs_queue.listeners.*.arn)}"
    endpoint_auto_confirms:          "false"
    protocol:                        "sqs"
    raw_message_delivery:            "true"
    topic_arn:                       "${element(aws_sns_topic.test.*.arn)}"

+ aws_sns_topic_subscription.sub-foo-to-bar.5
    arn:                             "<computed>"
    confirmation_timeout_in_minutes: "1"
    endpoint:                        "${element(aws_sqs_queue.listeners.*.arn)}"
    endpoint_auto_confirms:          "false"
    protocol:                        "sqs"
    raw_message_delivery:            "true"
    topic_arn:                       "${element(aws_sns_topic.test.*.arn)}"

+ aws_sqs_queue.listeners.0
    arn:                        "<computed>"
    delay_seconds:              "0"
    max_message_size:           "262144"
    message_retention_seconds:  "345600"
    name:                       "1-a"
    receive_wait_time_seconds:  "0"
    visibility_timeout_seconds: "30"

+ aws_sqs_queue.listeners.1
    arn:                        "<computed>"
    delay_seconds:              "0"
    max_message_size:           "262144"
    message_retention_seconds:  "345600"
    name:                       "1-b"
    receive_wait_time_seconds:  "0"
    visibility_timeout_seconds: "30"

+ aws_sqs_queue.listeners.2
    arn:                        "<computed>"
    delay_seconds:              "0"
    max_message_size:           "262144"
    message_retention_seconds:  "345600"
    name:                       "2-a"
    receive_wait_time_seconds:  "0"
    visibility_timeout_seconds: "30"

+ aws_sqs_queue.listeners.3
    arn:                        "<computed>"
    delay_seconds:              "0"
    max_message_size:           "262144"
    message_retention_seconds:  "345600"
    name:                       "2-b"
    receive_wait_time_seconds:  "0"
    visibility_timeout_seconds: "30"

+ aws_sqs_queue.listeners.4
    arn:                        "<computed>"
    delay_seconds:              "0"
    max_message_size:           "262144"
    message_retention_seconds:  "345600"
    name:                       "3-a"
    receive_wait_time_seconds:  "0"
    visibility_timeout_seconds: "30"

+ aws_sqs_queue.listeners.5
    arn:                        "<computed>"
    delay_seconds:              "0"
    max_message_size:           "262144"
    message_retention_seconds:  "345600"
    name:                       "3-b"
    receive_wait_time_seconds:  "0"
    visibility_timeout_seconds: "30"