IsBetterThan

Type alias for a function representing a reduction over a sequence of values trying to find the "best" value.

Return true if this is considered "better" than other, else return false.

This means that if this and other are considered equally "good", false should be returned.

You add additional constraints to an IsBetterThan function in the following fashion:

Let's say you want a value to always be returned when it satisfies the condition isPreferred(it), but in all other cases, you just want the best. Then you can write:

val isBetterThan: IsBetterThan<C>
val newIsBetterThan: IsBetterThan<C> = { other -> isPreferred(this) || (!isPreferred(other) && this.isBetterThan(other)) }

Alternatively, if you prefer a value not be returned when it satisfies the condition isNotPreferred(), then you can write:

val isBetterThan: IsBetterThan<C>
val newIsBetterThan: IsBetterThan<C> = { other -> !isNotPreferred(this) && (isNotPreferred(other) || this.isBetterThan(other)) }

Note that for the latter case, if the source contains only isNotPreferred()-satisfying values, a non-preferred value will still be returned.