39 lines
630 B
Go
39 lines
630 B
Go
package memento
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import (
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"errors"
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)
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type State struct {
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Description string
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}
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type memento struct {
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state State
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}
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type originator struct {
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state State
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}
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func (o *originator) StoreStateToMemento() memento {
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return memento{state: o.state}
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}
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func (o *originator) StoreStateFromMemento(m memento) {
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o.state = m.state
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}
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type careTaker struct {
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mementos []memento
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}
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func (c *careTaker) Push(m memento) {
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c.mementos = append(c.mementos, m)
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}
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func (c *careTaker) Get(i int) (memento, error) {
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var m memento
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if len(c.mementos) < i || i< 0 {
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return m, errors.New("Index is out of range")
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}
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return c.mementos[i], nil
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} |