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47 lines
791 B
Go
47 lines
791 B
Go
// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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// See page 106.
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// Embed demonstrates basic struct embedding.
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package main
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import "fmt"
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type Point struct{ X, Y int }
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type Circle struct {
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Point
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Radius int
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}
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type Wheel struct {
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Circle
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Spokes int
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}
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func main() {
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var w Wheel
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//!+
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w = Wheel{Circle{Point{8, 8}, 5}, 20}
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w = Wheel{
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Circle: Circle{
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Point: Point{X: 8, Y: 8},
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Radius: 5,
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},
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Spokes: 20, // NOTE: trailing comma necessary here (and at Radius)
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}
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fmt.Printf("%#v\n", w)
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// Output:
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// Wheel{Circle:Circle{Point:Point{X:8, Y:8}, Radius:5}, Spokes:20}
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w.X = 42
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fmt.Printf("%#v\n", w)
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// Output:
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// Wheel{Circle:Circle{Point:Point{X:42, Y:8}, Radius:5}, Spokes:20}
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//!-
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}
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