Enum Reducer 

pub enum Reducer {
    Error,
    Replace,
    Append,
    MergeObject,
    Sum,
    Max,
    Min,
    Custom(fn(&Value, &Value) -> Result<Value, String>),
}

Reducer 枚举 — 描述“这个 key 允许怎么合并“。

Variants

Error

冲突即报错

Replace

最后写入者胜

Append

数组追加

MergeObject

对象浅合并

Sum

数值求和

Max

取最大值

Min

取最小值

Custom(fn(&Value, &Value) -> Result<Value, String>)

自定义合并函数

Trait Implementations

impl Clone for Reducer

fn clone(&self) -> Reducer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Reducer

impl Debug for Reducer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Reducer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Reducer

impl PartialEq for Reducer

fn eq(&self, other: &Reducer) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Reducer