Enum FieldValue 

pub enum FieldValue {
    Absent,
    Present(Value),
}

One side of a field change: absent, or an explicit JSON value.

Option<serde_json::Value> cannot express this: with skip_serializing_if = "Option::is_none" an explicit Some(Value::Null) — “this field is being cleared” — is written as a missing key and reads back as None, so a review card that clears a field fails Interaction::verify_payload_hash after a round trip through any JSON store and its confirmation can never match. FieldValue keeps the two apart: Self::Absent omits the key, Self::Present writes the value, null included.

Variants

Absent

The field is not part of this side of the change.

Present(Value)

An explicit value. serde_json::Value::Null means “cleared”.

Implementations

impl FieldValue

pub fn present(value: impl Into<Value>) -> FieldValue

A present value.

pub fn cleared() -> FieldValue

An explicit JSON null: the field is being cleared.

pub fn is_absent(&self) -> bool

Returns true when the field is not part of this side.

pub fn value(&self) -> Option<&Value>

The value, when present.

Trait Implementations

impl Clone for FieldValue

fn clone(&self) -> FieldValue

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldValue

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

Formats the value using the given formatter.

impl Default for FieldValue

fn default() -> FieldValue

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for FieldValue

fn deserialize<D>( deserializer: D, ) -> Result<FieldValue, <D as Deserializer<'de>>::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for FieldValue

impl From<Value> for FieldValue

fn from(value: Value) -> FieldValue

Converts to this type from the input type.

impl PartialEq for FieldValue

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for FieldValue

fn serialize<S>( &self, serializer: S, ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for FieldValue