http://blog.boyangyue.com/tags/functional-programming/Recent content in Functional Programming on Boyang YueHugoen-usA Good Year AheadMon, 30 Nov 2020 09:47:00 +0900http://blog.boyangyue.com/2020/11/recursion-iteration-and-the-hidden-stack/Mon, 30 Nov 2020 09:47:00 +0900http://blog.boyangyue.com/2020/11/recursion-iteration-and-the-hidden-stack/<p>Repeated computation has two common surface forms. In an imperative loop, a counter or other state changes until a condition fails. In recursion, a function calls itself on a smaller or later version of the problem, and the runtime remembers what remains to be done.</p> <p>Imperative languages expose loops directly through constructs such as <code>for</code> and <code>while</code>. In pure functional programming languages like <a href="https://www.haskell.org/" target="_blank" rel="nofollow noopener noreferrer">Haskell</a>, however, there is no primitive imperative <code>for</code>/<code>while</code> syntax. That makes Haskell a useful place to ask the question directly: if the loop disappears from the language, what replaces it?</p>