60 lines
940 B
Go
60 lines
940 B
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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"encoding/json"
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"fmt"
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"reflect"
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"strings"
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)
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type item interface {
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discount(float64)
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fmt.Stringer
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}
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type schema struct {
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Category string
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Item item
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}
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type list []item
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func (l list) MarshalJSON() ([]byte, error) {
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var schemas []schema
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for _, it := range l {
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cat := reflect.TypeOf(it).Elem().Name()
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schemas = append(schemas, schema{cat, it})
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}
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return json.Marshal(schemas)
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}
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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 🚚."
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}
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var str strings.Builder
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for _, it := range l {
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str.WriteString(it.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 _, it := range l {
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it.discount(ratio)
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}
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}
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