One of the things people get excited about is meta-programming, which Jai has much more of than Odin.
Jai has a lot more weird stuff than Odin. Idiosyncratic features like if we're iterating through a sequence we can delete items as we go with a dedicated keyword, via a swap and shrink mechanism. Perhaps some of that weird stuff will be smoothed off during beta, or perhaps Jon will double down on it. But it does make Jai more interesting to talk about meanwhile than Odin which is a more "normal" language design.
I suspect I will never have reason to use either language "in anger" so to speak, but Jai is more interesting to me for the reasons I stated.
Pop and swap while iterating is definitely a useful feature. You can also queue removals up and do the pop and swap all together on a cleanup pass (snippet below). That said, most people don't code this way, so yeah, useful for sure.
Jai has a lot more weird stuff than Odin. Idiosyncratic features like if we're iterating through a sequence we can delete items as we go with a dedicated keyword, via a swap and shrink mechanism. Perhaps some of that weird stuff will be smoothed off during beta, or perhaps Jon will double down on it. But it does make Jai more interesting to talk about meanwhile than Odin which is a more "normal" language design.
I suspect I will never have reason to use either language "in anger" so to speak, but Jai is more interesting to me for the reasons I stated.