Re: Implement make-bow-stencil, make-tie-stencil for use in markup-commands undertie and overtie (issue 270640043 by address@hidden)

[dak]

Aaand another one.


https://codereview.appspot.com/270640043/diff/60001/scm/stencil.scm
File scm/stencil.scm (right):

https://codereview.appspot.com/270640043/diff/60001/scm/stencil.scm#newcode66
scm/stencil.scm:66: (if (equal? start stop)
I think that's too optimistic.  If you have
start = (0 . 0)
and
stop = (1e-200 . 1e-200)
then your length calculation will still throw out 0.  I'd recommend
doing this "foolproof" by starting with the length calculation and going
for the empty stencil exactly when the length is zero (since exactly
then dividing by it is a bad idea).

That would make this foolproof.  Yes, the additional indentation level
is a nuisance.

One can additionally increase precision by letting
(length-to-print (magnitude (make-rectangular dx dy)))
which turns out to still work when dx and dy are 1e-200 and similar
(meaning that their square would underflow precision at least on my
computer).

https://codereview.appspot.com/270640043/