.: package:HsYAML

Retrieve value in Mapping indexed by a !!str Text key. This parser fails if the key doesn't exist.

Retrieve optional value in Mapping indexed by a !!str Text key. Nothing is returned if the key is missing. This combinator only fails if the key exists but cannot be converted to the required type. NOTE: This is a variant of .:? which doesn't map a tag:yaml.org,2002:null node to Nothing.

Retrieve optional value in Mapping indexed by a !!str Text key. Nothing is returned if the key is missing or points to a tag:yaml.org,2002:null node. This combinator only fails if the key exists but cannot be converted to the required type. See also .:!.