Vector

Returns a function that takes an optional arg and uses it as the operand or injects a argument from some other source (e.g., HTML element, query string).

When called, the returned function returns the operand if it matches the type, otherwise returns an Error.

• IsArray = operand => (arg => Either<Error, Array)
• IsMap = operand => (arg => Either<Error, Map)
• IsSet = operand => (arg => Either<Error, Set)