proc toIter(it: seq[bool]): iterator: bool = return iterator: bool = for x in it: yield x proc realCountIt(it: iterator: bool, current: int): int = discard it() return if finished(it): current else: realCountIt(it, current + 1) proc count(it: seq[bool]): int = realCountIt(it.toIter, 0) let arr1 = newSeq[bool](1_000) let arr2 = newSeq[bool](100_000) echo arr1.count # this line works file echo arr2.count # this line Segmentation fault # due to main.nims, it will run as: # nim c --stacktrace:off -r main.nim # # or if you uncomment the line in main.nims script, it will run as: # nim c --stacktrace:off -t:-foptimize-sibling-calls -r main.nim # # but both of them will cause a Segmentation fault in line 19 #