It so happens that this was the topic of one of the posts in this series: https://jerf.org/iri/post/2025/fp_lessons_purity/#purity-is-relative https://jerf.org/

It so happens that this was the topic of one of the posts in this series: https://jerf.org/iri/post/2025/fp_lessons_purity/#purity-is-relative https://jerf.org/iri/post/2025/fp_lessons_purity/#purity-is-... I'm assuming from your post you haven't come from there, and we just coincidentally picked a similar example...