Struct prometrics::label::Label

pub struct Label { /* fields omitted */ }

Metric label.

A label is a key-value pair.

Label names may contain ASCII letters, numbers, as well as underscores. They must match the regex [a-zA-Z_][a-zA-Z0-9_]*. Label names beginning with __ are reserved for internal use.

Label values may contain any Unicode (utf-8) characters.

Methods

impl Label

pub fn new(name: &str, value: &str) -> Result<Self>

Makes a new Label instance.

Errors

If name contains invalid characters, this function returns ErrorKind::InvalidInput error.

Examples

use prometrics::ErrorKind;
use prometrics::label::Label;

let label = Label::new("foo", "bar").unwrap();
assert_eq!(label.name(), "foo");
assert_eq!(label.value(), "bar");
assert_eq!(label.to_string(), r#"foo="bar""#);

// Reserved name
assert_eq!(Label::new("__foo", "bar").err().map(|e| *e.kind()),
           Some(ErrorKind::InvalidInput));
// Invalid name
assert_eq!(Label::new("fo-o", "bar").err().map(|e| *e.kind()),
           Some(ErrorKind::InvalidInput));

pub fn name(&self) -> &str

Returns the name of this label.

pub fn value(&self) -> &str

Returns the value of this label.

Trait Implementations

impl Clone for Label

fn clone(&self) -> Label

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Label

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

Formats the value using the given formatter.

impl Display for Label

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

Formats the value using the given formatter.

impl Eq for Label

impl Hash for Label

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

Feeds this value into the given [Hasher].

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

Feeds a slice of this type into the given [Hasher].

impl Ord for Label

fn cmp(&self, other: &Label) -> Ordering

This method returns an [Ordering] between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialEq<Label> for Label

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<Label> for Label

fn partial_cmp(&self, other: &Label) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Label) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Label) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Label) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Label) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralEq for Label

impl StructuralPartialEq for Label