It seems like the distinction between stroke/fill is in the wrong place; stroke/fill are properties of the path, not its elements. A better purpose for arrow variants would be type of path element, e.g.,
arrow
meaning
> X, Y
move to X, Y
-> X, Y
line to X, Y
c> X, Y
smooth quadratic curve to X, Y
c> cX, cY X, Y
quadratic curve to X, Y with control point cX, cY
~> cX, cY X, Y
smooth cubic curve to X, Y with control point cX, cY
~> sX, sY eX, eY X, Y
cubic curve to X, Y with leading control point sX, sY and trailing control point eX, eY
-I Y
vertical line to Y
-- X
horizontal line to X
o> rX, rY X,Y
clockwise large-sweep arc to X, Y with radius rX, rY
<o rX, rY X,Y
counter-clockwise large-sweep arc to X, Ywith radius rX, rY
o< rX, rY X,Y
clockwise small-sweep arc to X, Ywith radius rX, rY
>o rX, rY X,Y
counter-clockwise small-sweep arc to X, Ywith radius rX, rY
It seems like the distinction between stroke/fill is in the wrong place; stroke/fill are properties of the path, not its elements. A better purpose for arrow variants would be type of path element, e.g.,
> X, YX, Y-> X, YX, Yc> X, YX, Yc> cX, cY X, YX, Ywith control pointcX, cY~> cX, cY X, YX, Ywith control pointcX, cY~> sX, sY eX, eY X, YX, Ywith leading control pointsX, sYand trailing control pointeX, eY-I YY-- XXo> rX, rY X,YX, Ywith radiusrX, rY<o rX, rY X,YX, Ywith radiusrX, rYo< rX, rY X,YX, Ywith radiusrX, rY>o rX, rY X,YX, Ywith radiusrX, rY