Курнат Андрей
48 lines
1.0 KiB
Go
48 lines
1.0 KiB
Go
package option
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import (
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"fmt"
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"github.com/lestrrat-go/blackmagic"
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)
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// Interface defines the minimum interface that an option must fulfill
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type Interface interface {
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// Ident returns the "identity" of this option, a unique identifier that
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// can be used to differentiate between options
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Ident() any
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// Value assigns the stored value into the dst argument, which must be
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// a pointer to a variable that can store the value. If the assignment
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// is successful, it return nil, otherwise it returns an error.
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Value(dst any) error
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}
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type pair[T any] struct {
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ident any
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value T
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}
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// New creates a new Option
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func New[T any](ident any, value T) Interface {
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return &pair[T]{
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ident: ident,
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value: value,
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}
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}
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func (p *pair[T]) Ident() any {
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return p.ident
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}
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func (p *pair[T]) Value(dst any) error {
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if err := blackmagic.AssignIfCompatible(dst, p.value); err != nil {
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return fmt.Errorf("failed to assign value %T to %T: %s", p.value, dst, err)
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}
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return nil
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}
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func (p *pair[T]) String() string {
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return fmt.Sprintf(`%v(%v)`, p.ident, p.value)
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}
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