86 lines
2.5 KiB
Plaintext
86 lines
2.5 KiB
Plaintext
/**
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* Proof of concept for Object-Oriented Programming in Boppi.
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* Note that this is a very basic notion of OO that only includes private
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* members. It does not support type checking, inheritance or public members.
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* It requires a tremendous amount of boilerplate to work without proper
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* tuples, parametrization or OO class syntax.
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*/
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//Declaring dummy functions for type aliases because Boppi disallows
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//the use of Void directly in a type.
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function intToVoid(int a) 0;
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function int voidToInt() 0;
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function class() 0;
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//Class declaration whose sole purpose is to make the code look better.
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//`Rectangle` type checks with every other `()->Void` type.
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var class Rectangle;
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//Helpers for making methods available outside their closure (the function
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//references should be passed via a return value if tuples were supported)
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//Assigning them immediately to suppress warnings.
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var voidToInt _getWidth; _getWidth := voidToInt;
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var intToVoid _setWidth; _setWidth := intToVoid;
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var voidToInt _getHeight; _getHeight := voidToInt;
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var intToVoid _setHeight; _setHeight := intToVoid;
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var voidToInt _getArea; _getArea := voidToInt;
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//Wrappers to make a `getWidth()` call less of an eyesore and allow you
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//to nest these calls without overriding the target closure in between
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function int getWidth (Rectangle rect) { rect();_getWidth() };
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function setWidth (Rectangle rect, int width) { rect();_setWidth(width) };
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function int getHeight(Rectangle rect) { rect();_getHeight() };
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function setHeight(Rectangle rect, int height) { rect();_setHeight(height) };
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function int getArea (Rectangle rect) { rect();_getArea() };
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//A class definition looks decent apart from the bind function to expose
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//the class methods. You can even add constructor arguments to your liking.
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function Rectangle newRectangle() {
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var int width;
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var int height;
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function int getWidth()
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width;
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function setWidth(int newWidth) {
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width := newWidth;
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};
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function int getHeight()
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height;
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function setHeight(int newHeight) {
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height := newHeight;
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};
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function int getArea()
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width*height;
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function bind() {
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_getWidth := getWidth;
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_setWidth := setWidth;
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_getHeight := getHeight;
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_setHeight := setHeight;
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_getArea := getArea;
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};
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bind
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};
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//Time to use the class
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var Rectangle a; a := newRectangle();
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var Rectangle b; b := newRectangle();
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setWidth(a, 4);
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setWidth(b, getWidth(a)+2);
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setHeight(b, 3);
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print(getArea(b));
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