foldr

The official Haskell blog has published a new article explaining the differences between foldl and foldr, the two core folding functions in the language. The post walks through how each function evaluates, why foldr works with lazy infinite lists while foldl generally does not, and which one is preferable in practice. Programmers are discussing the topic actively on Hacker News, where the item is trending, reflecting ongoing interest in Haskell's lazy evaluation model.