Struct Span 

pub struct Span { /* private fields */ }

A closed interval of durations: a magnitude that is known only to within a range.

Window is to Instant as Span is to Delta, and the pairing is what lets Rule U’s propagation actually happen. Rule J.2 requires an anchor’s uncertainty to reach every derived field, and an anchor is a window; the elapsed time from an uncertain anchor to an uncertain instant is therefore not a Delta but a Span, and typing it as one keeps the uncertainty from being dropped on the way through.

Implementations

impl Span

pub fn new(lo: Delta, hi: Delta) -> Result<Span>

Construct from bounds. UCAL-E0022 if inverted.

pub fn exact(d: Delta) -> Span

A magnitude known exactly.

pub fn zero() -> Span

Zero, exactly.

pub fn lo(&self) -> &Delta

Lower bound.

pub fn hi(&self) -> &Delta

Upper bound.

pub fn uncertainty(&self) -> Delta

How wide the uncertainty is.

pub fn is_exact(&self) -> bool

Whether the magnitude is known exactly.

pub fn checked_add(&self, other: &Span) -> Result<Span>

Interval addition: lo with lo, hi with hi (Rule U).

pub fn checked_sub(&self, other: &Span) -> Result<(Span, bool)>

Interval subtraction, [lo - other.hi, hi - other.lo].

The lower bound clamps at zero rather than failing: a magnitude is non-negative, and two overlapping spans genuinely admit a difference of zero. The clamp is reported so a caller can tell it happened.

pub fn midpoint(&self, mode: Rounding) -> Result<Delta>

Collapse to a single magnitude under an explicit mode (Rule U).

Trait Implementations

impl Clone for Span

fn clone(&self) -> Span

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Span

impl Debug for Span

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

Formats the value using the given formatter.

impl Eq for Span

impl PartialEq for Span

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Span