github.com/anth0d/nomad@v0.0.0-20221214183521-ae3a0a2cad06/website/content/docs/job-specification/hcl2/functions/collection/coalescelist.mdx (about)

     1  ---
     2  layout: docs
     3  page_title: coalescelist - Functions - Configuration Language
     4  description: |-
     5    The coalescelist function takes any number of list arguments and returns the
     6    first one that isn't empty.
     7  ---
     8  
     9  # `coalescelist` Function
    10  
    11  `coalescelist` takes any number of list arguments and returns the first one
    12  that isn't empty.
    13  
    14  ## Examples
    15  
    16  ```shell-session
    17  > coalescelist(["a", "b"], ["c", "d"])
    18  [
    19    "a",
    20    "b",
    21  ]
    22  > coalescelist([], ["c", "d"])
    23  [
    24    "c",
    25    "d",
    26  ]
    27  ```
    28  
    29  To perform the `coalescelist` operation with a list of lists, use the `...`
    30  symbol to expand the outer list as arguments:
    31  
    32  ```shell-session
    33  > coalescelist([[], ["c", "d"]]...)
    34  [
    35    "c",
    36    "d",
    37  ]
    38  ```
    39  
    40  ## Related Functions
    41  
    42  - [`coalesce`](/docs/job-specification/hcl2/functions/collection/coalesce) performs a similar operation with string
    43    arguments rather than list arguments.