Struct QualityItem

pub struct QualityItem<T> {
    pub item: T,
    pub quality: Quality,
}

Represents an item with a quality value as defined in RFC 7231 §5.3.1.

Parsing and Formatting

This wrapper be used to parse header value items that have a q-factor annotation as well as serialize items with a their q-factor.

Ordering

Since this context of use for this type is header value items, ordering is defined for QualityItems but only considers the item’s quality. Order of appearance should be used as the secondary sorting parameter; i.e., a stable sort over the quality values will produce a correctly sorted sequence.

Examples

let q_item: QualityItem<String> = "hello;q=0.3".parse().unwrap();
assert_eq!(&q_item.item, "hello");
assert_eq!(q_item.quality, q(0.3));

// note that format is normalized compared to parsed item
assert_eq!(q_item.to_string(), "hello; q=0.3");

// item with q=0.3 is greater than item with q=0.1
let q_item_fallback: QualityItem<String> = "abc;q=0.1".parse().unwrap();
assert!(q_item > q_item_fallback);

Fields

item: T

The wrapped contents of the field.

quality: Quality

The quality (client or server preference) for the value.

Implementations

impl<T> QualityItem<T>

pub fn new(item: T, quality: Quality) -> Self

Constructs a new QualityItem from an item and a quality value.

The item can be of any type. The quality should be a value in the range [0, 1].

pub fn max(item: T) -> Self

Constructs a new QualityItem from an item, using the maximum q-value.

pub fn min(item: T) -> Self

Constructs a new QualityItem from an item, using the minimum, non-zero q-value.

pub fn zero(item: T) -> Self

Constructs a new QualityItem from an item, using zero q-value of zero.

Trait Implementations

impl<T: Clone> Clone for QualityItem<T>

fn clone(&self) -> QualityItem<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for QualityItem<T>

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

Formats the value using the given formatter.

impl<T: Display> Display for QualityItem<T>

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

Formats the value using the given formatter.

impl<T: FromStr> FromStr for QualityItem<T>

type Err = ParseError

The associated error which can be returned from parsing.

fn from_str(q_item_str: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl<T: PartialEq> PartialEq for QualityItem<T>

fn eq(&self, other: &QualityItem<T>) -> 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<T: PartialEq> PartialOrd for QualityItem<T>

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl<T: Copy> Copy for QualityItem<T>

impl<T: Eq> Eq for QualityItem<T>

impl<T> StructuralPartialEq for QualityItem<T>