What are Alternative's “some” and “many” useful for?

Question

Alternative, an extension of Applicative, declares empty, <|> and these two functions:

One or more:

Answer 1

I tend to see them in Applicative parser combinator libraries.

a :: Parser [String]
a = some (string "hello")

and I see many used for purpose in the default definitions of Parsing in parsers.

I think Parsec being the primary example of a parser combinator library hides the use of some/many since it redefines things like (<|>).