Hello Jared, Thursday, March 16, 2006, 11:35:24 PM, you wrote: JU> General question to the list: JU> (Q) Are there any data structures in Haskell similar to C++/STL JU> vectors or C# generic Lists (i.e. strongly typed ArrayLists, e.g. JU> List<int>)? These data structures grow automatically as you add JU> elements to them (but in large chunks, not one node at a time). This JU> data structure (if it exists in Haskell) would run inside a monad (ST JU> and/or IO) and it would automaticly resize when needed, but would be JU> more or less like a mutable array except you can add new elements to JU> the end of it without reallocating an entire array of n+1 elements... i tried to implement this today :) but there is one problem: if i have (l,u) - array bounds of type Ix, and i - offending index of the same type, how can i compute new bounds of array so that it will grow in large chunks? there is no such computation operations for Ix type and that is logical - if this array is really a matrix then it's hard to use the same rules of extending it as for vectors such computation as (u-l)*2+l is great for integral indexes, but not for general case. now i plan to use this strategy for all enum types and just "grow to minimal and maximal indexes actually used" for other index types -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com