Enum Effect 

pub enum Effect {
    Read,
    ReversibleWrite,
    IrreversibleWrite,
}

Whether an operation observes the world or changes it, and whether the change can be taken back.

ADR 0001 asks each operation to say which of the three it is. The distinction is about the world outside the run, not about the host’s own bookkeeping: waiting is a Effect::Read because nothing outside the run is different afterwards.

Variants

Read

Observes state without changing it.

ReversibleWrite

Changes state in a way the same host can put back.

IrreversibleWrite

Changes state nothing can put back, such as bytes already on a terminal or a message already sent.

Trait Implementations

impl Clone for Effect

fn clone(&self) -> Effect

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Effect

impl Debug for Effect

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

Formats the value using the given formatter.

impl Display for Effect

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

Formats the value using the given formatter.

impl Eq for Effect

impl PartialEq for Effect

fn eq(&self, other: &Effect) -> 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 Effect