@JvmDefaultWithCompatibility
public interface SnapshotMutationPolicy<T>A policy to control how the result of mutableStateOf report and merge changes to the state object.
A mutation policy can be passed as an parameter to mutableStateOf, and compositionLocalOf.
Typically, one of the stock policies should be used such as referentialEqualityPolicy, structuralEqualityPolicy, or neverEqualPolicy. However, a custom mutation policy can be created by implementing this interface, such as a counter policy,
Functions
equivalent
public fun equivalent(a: T, b: T): BooleanDetermine if setting a state value's are equivalent and should be treated as equal. If equivalent returns true the new value is not considered a change.
merge
public fun merge(previous: T, current: T, applied: T): T?Merge conflicting changes in snapshots. This is only called if current and applied are not equivalent. If a valid merged value can be calculated then it should be returned.
For example, if the state object holds an immutable data class with multiple fields, and applied has changed fields that are unmodified by current it might be valid to return a new copy of the data class that combines that changes from both current and applied allowing a snapshot to apply that would have otherwise failed.
