» `coalescelist` Function

Note: This page is about Terraform 0.12 and later. For Terraform 0.11 and earlier, see 0.11 Configuration Language: Interpolation Syntax.

coalescelist takes any number of list arguments and returns the first one that isn't empty.

» Examples

> coalesce(["a", "b"], ["c", "d"])
[
  "a",
  "b",
]
> coalesce([], ["c", "d"])
[
  "c",
  "d",
]

To perform the coalesce operation with a list of lists, use the ... symbol to expand the outer list as arguments:

> coalesce([[], ["c", "d"]]...)
[
  "c",
  "d",
]

coalesce performs a similar operation with string arguments rather than list arguments.