Copyright © 2001-2005 Oren Ben-Kiki, Clark Evans, Brian Ingerson
Status
This specification is a draft reflecting consensus reached by members of the yaml-core mailing list. Any questions regarding this draft should be raised on this list.
URI:
tag:yaml.org,2002:omap
Shorthand:
!!omap
Kind:
Sequence.
Definition:
Ordered sequence of key:value pairs without duplicates.
A common type used for modeling is the ordered list of named values, where duplicates are not allowed. For example, this is the basic collection data type used by the PHP language.
Most programming languages do not have a built-in native data type
for supporting ordered maps. Such data types are usually provided
by libraries. If no such data type is available, an application may
resort to loading an “!!omap”
into a native array of hash tables containing one key each.
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.
Example 1. !!omap Examples
# Explicitly typed ordered map (dictionary). Bestiary: !!omap - aardvark: African pig-like ant eater. Ugly. - anteater: South-American ant eater. Two species. - anaconda: South-American constrictor snake. Scaly. # Etc. # Flow style Numbers: !!omap [ one: 1, two: 2, three : 3 ]