Struct http_stub::header::EntityTag
[−]
[src]
pub struct EntityTag {
pub weak: bool,
// some fields omitted
}An entity tag, defined in RFC7232
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 |
Fields
weak | Weakness indicator for the tag |