Loops

_loop
1. Few things to note
2. Pre & post mutations
_until
_map

_loop

Loop iterates over a list of items and returns an array of blocks.

key:
  _loop:
    items:
      - number: 3
      - number: 5
      - number: 9
    block:
      my_value: $item.number

will be rendered as

key:
  - my_value: 3
  - my_value: 5
  - my_value: 9

Few things to note

in the loop execution, the current item is accessible as a variable with $item.
an item can be a simple value (items is then a simple Array of items) or a dictionary.
when items are dictionaries, their subkeys can be reached with $item.subkey

Pre & post mutations

All items are mutated before being called by the _loop block.

When a block is generated using an item, it is mutated. It allows you to create complex structures easily.

items:
  - strings:
    - hello
    - world
  - strings:
    - foo
    - bar

global:
  merged: true

key:
  _loop:
    items: $items
    block:
      subkey:
        _concat: {items: $item.strings, sep: " "}
      _merge: $global

will be rendered as:

key:
  - subkey: hello world
    merged: true
  - subkey: foo bar
    merged: true

_until

_until repeats an action a certain amount of times, exposing a $item variable equal to the current iteration index.

Usage

key:
  _until: 3
  current_index: $item

Will be rendered as

key:
  - current_index: 0
  - current_index: 1
  - current_index: 2

_map

_map returns an array of mutated values using a no-argument function call.