In practice, I've found space leaks in Haskell code to be a bit analogous to extraneous copies in C++ code or NullPointerExceptions in Java: They're usually no

In practice, I've found space leaks in Haskell code to be a bit analogous to extraneous copies in C++ code or NullPointerExceptions in Java: They're usually not a huge problem, but sometimes you get it wrong even if you're experienced and know what you're doing. We've only had one really disasterous space leak and it was caught and reverted right away. The hardest ones are generally the slow ones where the servers take 3-7 days to run out of RAM and fall over. If you never go more than a few hours without a code push, you might not even notice it.