H. <[EMAIL PROTECTED]> writes: > Hello @ all, > > Sometimes one has an imperative algorithm, and wants to write a program in > Haskell which do has the same effect... > > So the question is - how a construct as the following can efficiently be > written? > > -- > Pseudo code: > n[1..10000] = false > for (1..10000) |i| > for (i,2*i..10000) |j| > n[j] = not n[j] > -- > > Certainly it is in this special case equivalent to (True where the index is): > map (^2) [1..100] > > But I mean the destructive updates in the imperative code in Haskell without > filling the (many times more than in imperative languages) memory with > recursively called functions...
The idea in Haskell is not to think of stepping through the array. Look at accumArray and ixmap. -- Jón Fairbairn [EMAIL PROTECTED] _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
