tc39
Rounding mode "halfExpand" instead of "halfCeil"
Assuming that the rounding mode "halfEven" corresponds to the IEEE rounding mode "roundTiesToEven", it looks like "halfCeil" is meant to correspond to "roundTiesToAway". However, because "ceiling" usually means rounding "toward +∞", should "halfCeil" rather be "halfExpand" (i.e., "expand" == "away from zero")?
It looks like the proposal was updated to use the official rounding mode names. This removes the confusion.
One thing to note is that it now does not align with the Temporal rounding mode names anymore. I wish they would have used the official names as well.
Right, we now use halfExpand rather than halfCeil, which is unsupported. That was a mistake on my part; sorry for the confusion.
Since the rounding mode names were changed back to align with the existing names in the spec, I'm closing this issue.