Length

Compares operand to test (an Integer) and 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, session storage).

When called, the returned function returns the operand if it is more/less/etc. than the test number, otherwise returns an Error.

TODO: Extend to cover arrays.

• IsLength = (datatype = "String") => operand => test => => (arg => Either<Error, String)
• IsLongerThan = (datatype = "String") => operand => test => => (arg => Either<Error, String)
• IsNoLongerThan = (datatype = "String") => operand => test => => (arg => Either<Error, String)
• IsNoShorterThan = (datatype = "String") => operand => test => => (arg => Either<Error, String)
• IsNotLength = (datatype = "String") => operand => test => => (arg => Either<Error, String)
• IsShorterThan = (datatype = "String") => operand => test => => (arg => Either<Error, String)