After my (naive) mergesort implementation from yesterday used around 730 MB of RAM to sort a (26 MB) file containing approx. 400,000 strings I consulted the good folks on the #haskell IRC channel.
Their advice was to use byte strings as opposed to normal strings since the former perform much better.
I tried that and observed that the RAM utilisation and run-time went down by approximately 85% !
The reduced RAM utilisation was attributed to the more efficient byte strings and the improved run-time performance to the reduced garbage collection overhead respectively.
The difference between the source files (mergesort.hs, Scaffolding.hs) is minimal and switching over to byte strings was facilitated by the fact that they expose the same interface as normal strings.
Nice!
