Struct EntityTag

pub struct EntityTag {
    pub weak: bool,
    /* private fields */
}

An entity tag, defined in [RFC 7232 §2.3].

An entity tag consists of a string enclosed by two literal double quotes. Preceding the first double quote is an optional weakness indicator, which always looks like W/. Examples for valid tags are "xyzzy" and W/"xyzzy".

ABNF

entity-tag = [ weak ] opaque-tag
weak       = %x57.2F ; "W/", case-sensitive
opaque-tag = DQUOTE *etagc DQUOTE
etagc      = %x21 / %x23-7E / obs-text
           ; VCHAR except double quotes, plus obs-text

Comparison

To check if two entity tags are equivalent in an application always use the strong_eq or weak_eq methods based on the context of the Tag. Only use == to check if two tags are identical.

The example below shows the results for a set of entity-tag pairs and both the weak and strong comparison function results:

ETag 1	ETag 2	Strong Comparison	Weak Comparison
W/"1"	W/"1"	no match	match
W/"1"	W/"2"	no match	no match
W/"1"	"1"	no match	match
"1"	"1"	match	match

RFC 7232 §2.3

Fields

weak: bool

Weakness indicator for the tag

Implementations

impl EntityTag

pub fn new(weak: bool, tag: String) -> EntityTag

Constructs a new EntityTag.

Panics

If the tag contains invalid characters.

pub fn new_weak(tag: String) -> EntityTag

Constructs a new weak EntityTag.

Panics

If the tag contains invalid characters.

pub fn weak(tag: String) -> EntityTag

👎Deprecated since 3.0.0: Renamed to new_weak.

pub fn new_strong(tag: String) -> EntityTag

Constructs a new strong EntityTag.

Panics

If the tag contains invalid characters.

pub fn strong(tag: String) -> EntityTag

👎Deprecated since 3.0.0: Renamed to new_strong.

pub fn tag(&self) -> &str

Returns tag.

pub fn set_tag(&mut self, tag: impl Into<String>)

Sets tag.

Panics

If the tag contains invalid characters.

pub fn strong_eq(&self, other: &EntityTag) -> bool

For strong comparison two entity-tags are equivalent if both are not weak and their opaque-tags match character-by-character.

pub fn weak_eq(&self, other: &EntityTag) -> bool

For weak comparison two entity-tags are equivalent if their opaque-tags match character-by-character, regardless of either or both being tagged as “weak”.

pub fn strong_ne(&self, other: &EntityTag) -> bool

Returns the inverse of strong_eq().

pub fn weak_ne(&self, other: &EntityTag) -> bool

Returns inverse of weak_eq().

Trait Implementations

impl Clone for EntityTag

fn clone(&self) -> EntityTag

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for EntityTag

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

Formats the value using the given formatter.

impl Display for EntityTag

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

Formats the value using the given formatter.

impl FromStr for EntityTag

type Err = ParseError

The associated error which can be returned from parsing.

fn from_str(slice: &str) -> Result<EntityTag, ParseError>

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

impl PartialEq for EntityTag

fn eq(&self, other: &EntityTag) -> 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 TryIntoHeaderValue for EntityTag

type Error = InvalidHeaderValue

The type returned in the event of a conversion error.

fn try_into_value(self) -> Result<HeaderValue, Self::Error>

Try to convert value to a HeaderValue.

impl Eq for EntityTag

impl StructuralPartialEq for EntityTag