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YAML Ordered Mappings

YAML Ordered Mappings with !!omap​

!!omap defines an ordered sequence of key:value pairs without duplicates.

For example:

ordered: !!omap
- Tom Nolan: 23
- Ryan Raynolds: 45
- Thomas Anderson: 28
Equivalent JSON
{
  "ordered": [
     {"Tom Nolan": 23},
     {"Ryan Raynolds": 45},
     {"Thomas Anderson": 28}
  ]
}
note

Note where the !!omap type is specified in the yaml file to preserve the order of the elements!

note

You can also use the flow style to define an ordered mapping:

ordered: !!omap [Tom Nolan: 23, Ryan Raynolds: 45, Thomas Anderson: 28]
note

The !!omap tag may be given explicitly.

Alternatively, the application may choose to implicitly type a sequence of single-key mappings to ordered maps. In this case, an explicit !seq transfer must be given to sequences of single-key mappings that do not represent ordered maps.

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