keen/compare

Source

This is a standard module and does not need to be explicitly imported.

Functions for comparison.

If you want a type to be comparable, just define == and <=>. Use the signatures defined in the compare spec.

Other functions like != are defined here, derived from those.

comparison enum

less

equal

greater

Result of comparison.

If a <=> b is equal, then any function on a should return ths same result as a on b.

equal[t] spec

== bool(a t, b t)

compare[t] spec

<=> comparison(a t, b t)

When defined for mutable values, this should compare their content without regard to mutablility; so it may consider values equal that may not be equal in the future.

- comparison(a comparison)

Opposite comparison

!=[t] bool(a t, b t) t equal

Opposite of a == b

<[t] bool(a t, b t) t compare

True iff (a <=> b) == comparison.

<=[t] bool(a t, b t) t compare

True iff (a <=> b) != comparison.

>[t] bool(a t, b t) t compare

True iff (a <=> b) == comparison.

>=[t] bool(a t, b t) t compare

True iff (a <=> b) != comparison.

min[t] t(a t, b t) t compare

Returns the lesser argument. Returns b if they are equal.

max[t] t(a t, b t) t compare

Returns the greater argument. Returns b if they are equal.

compare-reverse[t] record

inner t

Wraps a value and reverses comparison (so less becomes greater and vice versa)