Struct Measured 

pub struct Measured { /* private fields */ }

One value as the app knows it: a measurement with provenance, or the reason it has none.

Implementations

impl Measured

pub fn known( measure: Measure, value: impl Into<String>, source: impl Into<String>, as_of: SystemTime, expected: Option<Duration>, ) -> Measured

A reading of value in measure, taken at as_of from source. expected is how long the reading is good for before it is stale; None means the app has no interval to judge it by.

pub fn unknown(measure: Measure, reason: impl Into<String>) -> Measured

The designed “we did not measure this” state: an em dash and why.

pub fn measure(&self) -> &Measure

What is being claimed.

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

The measured value, or None when nothing was measured. Never Some for an unknown fact: zero is a measurement like any other.

pub fn value_or_dash(&self) -> &str

The value in a value position: the reading, or the em dash that means “not known” (never a zero).

pub fn source(&self) -> Option<&str>

Where the reading came from, when it was measured.

pub fn as_of(&self) -> Option<SystemTime>

When the reading was taken.

pub fn unknown_reason(&self) -> Option<&str>

Why the fact is unknown, when it is.

pub fn age(&self, now: SystemTime) -> Option<Duration>

How old the reading is at now, never negative.

pub fn is_stale(&self, now: SystemTime) -> bool

Whether the reading is older than the interval it was measured for. An unknown fact is stale by definition; a fact with no expected interval is never judged stale.

pub fn caption(&self, now: SystemTime) -> String

The caption line under the value: provenance, age and — when it has outlived its interval — that it is stale. Unknown facts say why and nothing else.

Captions are English fallbacks for a view with no catalog entry. An app with localized copy can build the same line from source, age and is_stale.

Trait Implementations

impl Clone for Measured

fn clone(&self) -> Measured

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Measured

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

Formats the value using the given formatter.

impl PartialEq for Measured

fn eq(&self, other: &Measured) -> 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 Eq for Measured

impl StructuralPartialEq for Measured