Inline coordinate casting

[ysndr]

So we only iterate once...
Sorry, got in my head ^^

[Radvendii]

My instinct changing this to a fold makes things slightly less readable, but I think that might just be because I'm used to the other version. A fold might actually make more sense here. What do you think? Obviously it's more efficient, but is it as readable? I've stared at the code for too long to be able to tell.

[ysndr]

yes, I guess the x y xs ys and additional parenthesis didn't help with readability.
It should be faster though.
It doesn't scream at you that it's doing an unzip so thats an additional comment somewhere.
If its not requiring to be the most performant thing i suggest we can keep this as an academic exercise and leave it as it is.

Like, i don't know how big the metric data would be and if iterating it twice would be noticeable.