There are several Intent Parser examples for Adapt on GitHub, and this page walks you through what they are, and where you might use them.
This sample Intent Parser uses a fixed vocabulary to extract entities for an Intent. This type of intent parser is useful when the parameters of the Intent are well-bounded; that is, the possible Utterances are well known.
This sample Intent Parser uses multiple Intents, and disambiguates between them using intent confidence. For example, if one Intent has a higher confidence than the second, the Intent Parser will assume the first Intent.
This sample Intent Parser uses a regular expression entity to extract location from a query. This type of Intent Parser is useful where a parameter needs to be extracted from a query and it takes a form that can be expressed in regex. Other parameters that are often expressed in regex are IP address, names of people and colors.