Change alias name of type.
Adjust things related to scale and magnification.
Change type of [degree].
Implement [addEdge].
Implement [getEdge] and [getReversedEdge].
Add [compile] function to [make].
Fixed defect of [getEdge].
Amend implementation of things related to [Edge].
Fix trivial mistake.
Remove test code.
Fix trivial mistakes.
Implement things related to [addCursorEdges].
Implement things related to [removeCursorEdges].
Change interface of methods related to [Edge].
Implement method to check validness of [Edge].
Separate implementation of methods related to edge check.
Update [array.hpp].
Complete [Edge] check methods.
Make type of [degree] exact.
Change interface of flipping a little.