Struct EscalationLadder

pub struct EscalationLadder { /* private fields */ }

The precision tiers a filtered predicate steps through, weakest first.

This is the executable form of the fast-path/escalation design: try a cheap filter, and only pay for stronger arithmetic on the cases that need it. A backend advertises how far it can escalate; a caller learns whether the answer it got was cheap or expensive.

Implementations

impl EscalationLadder

pub const fn new(ceiling: Precision) -> EscalationLadder

A ladder that may escalate up to and including ceiling.

pub const fn exact() -> EscalationLadder

A ladder ending in exact arithmetic: every sign is decidable.

pub const fn ceiling(self) -> Precision

Highest precision this ladder may reach.

pub const fn is_total(self) -> bool

Whether reaching ceiling guarantees every sign becomes decidable.

Only exact arithmetic does. A ladder topping out at F64 can still return Uncertain, and a caller that needs a decision must know that.

pub fn next_after(self, current: Precision) -> Option<Precision>

The next tier to try after current, or None at the ceiling.

pub fn permits(self, precision: Precision) -> bool

Whether this ladder may use precision.

pub fn rungs(self) -> impl Iterator<Item = Precision>

Tiers this ladder will actually attempt, in order.

Trait Implementations

impl Clone for EscalationLadder

fn clone(&self) -> EscalationLadder

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for EscalationLadder

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

Formats the value using the given formatter.

impl Hash for EscalationLadder

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for EscalationLadder

fn eq(&self, other: &EscalationLadder) -> 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 Copy for EscalationLadder

impl Eq for EscalationLadder

impl StructuralPartialEq for EscalationLadder