# Functions
Applicator turns function "R[f]: X => Y" into "f: X => R[Y]".
Compose takes two functions of the form "xy: R[X] => R[Y]" and "yz: R[Y] => R[Z]" and returns a function "xz(R[X]) => R[Z]".
Error returns a R that is an error.
FlatMap turns function "f: X => R[Y]" into "f: R[X] => R[Y]".
Lift converts a function of the form "f: X => Y" to the form "f: X => R[Y]" where R[Y] == Some(y).
Map turns function "f: X => Y" into "f: R(X) => R[Y]".
New returns a R.
Some returns a R that contains a value and is not an error.
UnwrapFunc converts a function of the form "f(a) => R[T]" to the form "f(a) => (T, error)".
WrapFunc converts a function of the form "f(a) => (a, error)" to the form "f(a) => R[Y]".