Are some data structures more suitable for functional programming than others?

Question

In Real World Haskell, there is a section titled \"Life without arrays or hash tables\" where the authors suggest that list and trees are preferred in functional programming, w

Answer 1

Yes, the primary difference is immutability of the data, which can include code (see higher order functions). See the Wikipedia page on Purely Functional for a list of the common data types and usages. Whether its a problem or not depends on how you look at it. There are many advantages to programming in a functional language if it fits the type of task you are working on. A hash table is a type of associative array, but isn't the one you want to use in a functional language because of the rehashing you'd have to do on insert and the poor performance without arrays. Instead, try the Haskell implementation of Data.Map for an associative array.