Last modified by chrisby on 2024/03/03 17:01

From version 3.5
edited by chrisby
on 2024/03/03 15:17
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To version 2.3
edited by chrisby
on 2024/03/03 14:44
Change comment: There is no comment for this version

Summary

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... ... @@ -1,40 +1,30 @@
1 -### Use Cases
1 +asd
2 2  
3 -This example is intended to demonstrate the extensibility differences between data structures and objects by extending them with
3 +```
4 +type Square struct {
5 + length float
6 +}
4 4  
5 -1. an Area() function (extending behavior)
6 -1. a rectangle type (extending data type)
8 +type Circle struct {
9 + length float
10 +}
7 7  
8 -### Data Structure Style
12 +func Area(g GeometricObject) float {
13 + switch (g.type()):
14 + case Circle:
15 + return
16 + case Square:
17 + return ...
18 +}
9 9  
10 - struct Square {
11 - length float
12 - }
13 -
14 - struct Circle {
15 - radius float
16 - }
17 -
18 - function Circumference(g Object) float {
19 - switch type(g):
20 - case Square:
21 - return 4 * g.length
22 - case Circle:
23 - return 2 * PI * g.radius
24 - }
20 +func Circumference(g GeometricObject) float {
21 + ...
22 +}
23 +```
25 25  
26 -1. Adding a function Area() with the same anatomy as Circumference() is easy, since it only requires adding new code.
27 -1. Adding a new datatype, Rectangle, is more difficult because it requires touching existing code, namely any functions like Circumference() or Area() that need to be enabled handle this datatype.
28 -
29 -####
30 -
31 31  #### Object-Oriented Style
32 32  
33 - interface GeometricObject {
34 - Circumference() float
35 - }
36 -
37 - class Square implements GeometricObject {
27 + class Square {
38 38   length float
39 39  
40 40   constructor(length float) {
... ... @@ -41,12 +41,16 @@
41 41   this.length = length
42 42   }
43 43  
34 + func Area() float {
35 + return this.length * this.length
36 + }
37 +
44 44   func Circumference() float {
45 45   return 4 * this.length
46 46   }
47 47   }
48 48  
49 - class Circle implements GeometricObject {
43 + class Circle {
50 50   radius float
51 51  
52 52   constructor(radius float) {
... ... @@ -53,6 +53,10 @@
53 53   this.radius = radius
54 54   }
55 55  
50 + func Area() float {
51 + return PI * this.radius * this.radius
52 + }
53 +
56 56   func Circumference() float {
57 57   return 2 * PI * this.radius
58 58   }