46 lines
798 B
Go
46 lines
798 B
Go
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// Copyright (c) 2012, Matt T. Proud
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// All rights reserved.
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//
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// optional.go provides a mechanism for safely getting a set value or falling
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// back to defaults.
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package utility
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type Optional struct {
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value interface{}
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}
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func EmptyOptional() *Optional {
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emission := &Optional{value: nil}
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return emission
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}
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func Of(value interface{}) *Optional {
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emission := &Optional{value: value}
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return emission
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}
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func (o *Optional) IsSet() bool {
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return o.value != nil
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}
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func (o *Optional) Get() interface{} {
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if o.value == nil {
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panic("Expected a value to be set.")
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}
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return o.value
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}
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func (o *Optional) Or(a interface{}) interface{} {
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if o.IsSet() {
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return o.Get()
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}
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return a
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}
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