Am 28.03.19 um 19:26 schrieb Vanessa McHale:
That got me thinking - what exactly is wrong with lazy I/O? I've seen Oleg Kiselyov's paper (http://okmij.org/ftp/Haskell/#lazyIO-not-True) and I've run into issues myself (basically the issue here: https://stackoverflow.com/questions/31342012/read-and-writing-to-file-in-has...), but none of those seem so pathological - the second issue could be better resolved with linear types!
As far as I recall, IO was the nasty loophole in Haskell initially, and after lots of ugly hackery and living with the pain, various approaches emerged. Today's IO system was one of the, and there were two contenders. IO won because it was the first one to become useful, and while at least one of the others made it to the proof-of-concept stages, IO had started to mature already and the contender never managed to get much mind share. So... it's part historical accident, part "nobody had a better idea at the time". Which means that there could well be better alternatives, but it's unclear how to judge whether some alternative is really better, so even people with an interest in the field tend to research on other topics. Regards, Jo