55 lines
1.1 KiB
Go
55 lines
1.1 KiB
Go
// For more tutorials: https://blog.learngoprogramming.com
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//
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// Copyright © 2018 Inanc Gumus
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// Learn Go Programming Course
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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//
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package main
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import (
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"sort"
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"strings"
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)
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type list []*product
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func (l list) String() string {
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if len(l) == 0 {
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return "Sorry. We're waiting for delivery 🚚.\n"
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}
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var str strings.Builder
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for _, p := range l {
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// fmt.Printf("* %s\n", p)
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str.WriteString("* ")
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str.WriteString(p.String())
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str.WriteRune('\n')
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}
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return str.String()
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}
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func (l list) discount(ratio float64) {
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for _, p := range l {
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p.discount(ratio)
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}
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}
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// implementation of the sort.Interface:
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// by default `list` sorts by `Title`.
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func (l list) Len() int { return len(l) }
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func (l list) Less(i, j int) bool { return l[i].Title < l[j].Title }
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func (l list) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
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// byRelease sorts by product release dates.
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type byRelease struct{ list }
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func (bp byRelease) Less(i, j int) bool {
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return bp.list[i].Released.Before(bp.list[j].Released.Time)
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}
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func byReleaseDate(l list) sort.Interface {
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return &byRelease{l}
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}
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