10.13.6 Debugging tips
A few questions to ask yourself when working with pure properties:
- Is the property really pure? Are you sure that its value could
not be changed later in the compiling process due to other changes?
- Can the property be made to correspond even more exactly with the
eventual impure property?
- For a spanner, is the pure property changing correctly depending
on the starting and ending points of the spanner?
- For an Item, will the item’s pure height need to act in horizontal
spacing but not in vertical spacing? If so, use extra-spacing-height
instead of pure height.