Hi guys, I've started playing with Iteratee and Enumerators: very cool and addictive stuff. I have wrote this simple code: https://gist.github.com/3899017 In a nutshell, it gives back the number of occurences for a single char in case the argument passed from the command line is a single char, or the number of lines of the entire file. I've tried it first on a small file (~100MB) and then on a huge one (~3GB). As far as I understood Iteratee IO should be a smart way to do IO, avoiding to keep the entire file in memory; what I observe in the second case, instead, is a sort of memory leak. The memory grows and grows until the entire machine hangs. If I split the huge file in "small" chunks, memory comsumption is still high but the computation terminates and is fast. So my two questions: a) What am I missing? Should be memory used be constant? And how can I achieve this purpose? b) I'm using the package enumerator because as far as I can see is the most used. How does it compares with "iteratee"? Which of the two are more performant? Bye and thanks, A.