In Wordy, suppose that BinaryExpressionNode were designed like this, with the operator modeled as a string:
public class BinaryExpressionNode extends ExpressionNode {
// Valid operator types include "addition", "subtraction", "multiplication",
// "division", and "exponentiation". Other strings are not valid operators.
| # ------ Base class with metaprogramming ------ | |
| # This might make more sense if you skip ahead to the 🦄🦄🦄🌈🌈🌈 first | |
| # and study the desired results, then come back here. | |
| class Animal | |
| def initialize(name) | |
| @name = name | |
| end |
| # How can we harmonize the types of a Square class and a Rectangle class | |
| # so that it's possible to write a rescale function that works on both? | |
| # | |
| # As we saw in class Wed, if we’re doing this in Java, inheritance cannot | |
| # solve this problem in a simple way: both `Square extends Rectangle` | |
| # and `Rectangle extends Square` end up violating the Liskov Substitution | |
| # Principle. While there is a nice “is-a” relationship here — all squares | |
| # are rectangles! — that does not translate nicely into Java’s type system. | |
| # | |
| # In class today, we saw that having one inherit from the other doesn’t |
| body.app-body.layout-multiple-columns.theme-mastodon-light, | |
| body.app-body.layout-multiple-columns.theme-default, | |
| body.app-body.layout-multiple-columns.theme-contrast { | |
| overflow: hidden !important; | |
| } | |
| body.app-body.layout-multiple-columns.theme-mastodon-light .columns-area, | |
| body.app-body.layout-multiple-columns.theme-default .columns-area, | |
| body.app-body.layout-multiple-columns.theme-contrast .columns-area { | |
| margin: 0 -1px !important; |