<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">I’m not certain, but think you might be describing hylomorphism:<div class=""><a href="https://medium.com/@JosephJnk/hylomorphisms-43a5494729b7" class="">https://medium.com/@JosephJnk/hylomorphisms-43a5494729b7</a></div><div class=""><br class=""></div><div class="">-db</div><div class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Aug 19, 2019, at 5:00 AM, <a href="mailto:haskell-cafe-request@haskell.org" class="">haskell-cafe-request@haskell.org</a> wrote:</div><br class="Apple-interchange-newline"><div class=""><span style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Does a function of this general nature exist in some package already?</span><br style="caret-color: rgb(0, 0, 0); font-family: Menlo-Regular; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""></div></blockquote></div><br class=""></div></body></html>