Documentation
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Index ¶
- type Option
- func (o Option[T]) And(fn func(T) T) Option[T]
- func (o Option[T]) AndThen(fn func(T) Option[T]) Option[T]
- func (o Option[T]) IsNone() bool
- func (o Option[T]) IsSome() bool
- func (o Option[T]) MarshalJSON() ([]byte, error)
- func (o *Option[T]) Scan(value any) error
- func (o *Option[T]) UnmarshalJSON(data []byte) error
- func (o Option[T]) Unwrap() T
- func (o Option[T]) UnwrapOr(value T) T
- func (o Option[T]) UnwrapOrDefault() T
- func (o Option[T]) UnwrapOrElse(fn func() T) T
- func (o Option[T]) Value() (driver.Value, error)
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Option ¶
type Option[T any] struct { // contains filtered or unexported fields }
Option represents a values that represents a values existence.
nil is usually used on Go however this has two problems: 1. Checking if the return values is nil is NOT enforced and can lead to panics. 2. Using nil is not good enough when nil itself is a valid value.
This implements the sql.Scanner interface and can be used as a sql value for reading and writing. It supports: - String - Bool - Uint8 - Float64 - Int16 - Int32 - Int64 - interface{}/any - time.Time - Struct - when type is convertable to []byte and assumes JSON. - Slice - when type is convertable to []byte and assumes JSON. - Map types - when type is convertable to []byte and assumes JSON.
This also implements the `json.Marshaler` and `json.Unmarshaler` interfaces. The only caveat is a None value will result in a JSON `null` value. there is no way to hook into the std library to make `omitempty` not produce any value at this time.
func (Option[T]) And ¶ added in v5.23.0
And calls the provided function with the contained value if the option is Some, returns the None value otherwise.
func (Option[T]) AndThen ¶ added in v5.23.0
AndThen calls the provided function with the contained value if the option is Some, returns the None value otherwise.
This differs from `And` in that the provided function returns an Option[T] allowing changing of the Option value itself.
func (Option[T]) MarshalJSON ¶
MarshalJSON implements the `json.Marshaler` interface.
func (*Option[T]) UnmarshalJSON ¶
UnmarshalJSON implements the `json.Unmarshaler` interface.
func (Option[T]) Unwrap ¶
func (o Option[T]) Unwrap() T
Unwrap returns the values if the option is not empty or panics.
func (Option[T]) UnwrapOr ¶ added in v5.22.0
func (o Option[T]) UnwrapOr(value T) T
UnwrapOr returns the contained `Some` value or provided default value.
Arguments passed to `UnwrapOr` are eagerly evaluated; if you are passing the result of a function call, look to use `UnwrapOrElse`, which can be lazily evaluated.
func (Option[T]) UnwrapOrDefault ¶ added in v5.22.0
func (o Option[T]) UnwrapOrDefault() T
UnwrapOrDefault returns the contained `Some` value or the default value of the type T.
func (Option[T]) UnwrapOrElse ¶ added in v5.22.0
func (o Option[T]) UnwrapOrElse(fn func() T) T
UnwrapOrElse returns the contained `Some` value or computes it from a provided function.
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