A Filter takes a value a and determines whether it should pass or fail.

The result of a filter.

Pass if all filters pass.

Pass if both filters pass.

Pass if at least one filter passes.

Keep items that pass the filter.

Filter a value by a derived property, like its height.

bob =
    { height = 5 }


isTall =
    by .height <| gt 6


test isTall bob
-- Fail

Sometimes the building blocks in this library aren't enough!

Test whether a value is equal to ref.

A filter that always fails.

Test whether a value is greater than num.

Keep items that pass the filter.

Test whether a value is less than num.

Flip the outcome of a filter; if it fails it passes, and if it passes it fails.

Pass if at least one filter passes.

A filter that always passes.

Run an item through a given filter.

Test whether a value is greater than or equal to num.

Test whether a value is less than or equal to num.

Test whether a value is not equal to ref.