PdefnGui displays a PdefnGui, and allows editing and evaluating its code.
Pdefn
JITGui methods:
test whether object can be displayed
g = PdefnGui();
Pdefn(\abc, [1, 2, 3]);
g.object_(Pdefn(\abc));
Pdefn(\abc, 345);
// Note: When editing code in the csView and evaluating,
// there is a short delay before displaying. this is intended.