Struct Selector 

pub struct Selector<'a> { /* private fields */ }

A selector is the combination of a Key Expression, which defines the set of keys that are relevant to an operation, and a set of Parameters, with a few intended uses:

• specifying arguments to a queryable, allowing the passing of Remote Procedure Call parameters,
• filtering by value,
• filtering by metadata, such as the timestamp of a value,
• specifying arguments to zenoh when using the REST API.

When in string form, selectors look a lot like a URI, with similar semantics:

• the key_expr before the first ? must be a valid key expression.
• the parameters after the first ? should be encoded like the query section of a URL:
  • parameters are separated by ;,
  • the parameter name and value are separated by the first =,
  • in the absence of =, the parameter value is considered to be the empty string,
  • both name and value should use percent-encoding to escape characters,
  • defining a value for the same parameter name twice is considered undefined behavior, with the encouraged behavior being to reject operations when a duplicate parameter is detected.

Zenoh intends to standardize the usage of a set of parameter names. To avoid conflicting with RPC parameters, the Zenoh team has settled on reserving the set of parameter names that start with non-alphanumeric characters.

The full specification for selectors is available here, It includes standardized parameters.

Queryable implementers are encouraged to prefer these standardized parameter names when implementing their associated features, and to prefix their own parameter names to avoid having conflicting parameter names with other queryables.

Here are the currently standardized parameters for Zenoh (check the specification page for the exhaustive list):

• [unstable] _time: used to express interest in only values dated within a certain time range; values for this parameter must be readable by the Zenoh Time DSL for the value to be considered valid.
• [unstable] _anyke: used in queries to express interest in replies coming from any key expression. By default, only replies whose key expression matches the query’s key expression are accepted. _anyke disables the query-reply key expression matching check.

Implementations

impl<'a> Selector<'a>

pub fn key_expr(&self) -> &KeyExpr<'a>

Get the KeyExpr of this selector.

pub fn parameters(&self) -> &Parameters<'a>

Get the Parameters of this selector.

pub fn split(self) -> (KeyExpr<'a>, Parameters<'a>)

Deconstruct the selector into (KeyExpr, Parameters)

pub fn owned<K, P>(key_expr: K, parameters: P) -> Self

where K: Into<KeyExpr<'a>>, P: Into<Parameters<'a>>,

Builds a new selector which owns keyexpr and parameters

pub fn borrowed( key_expr: &'a KeyExpr<'a>, parameters: &'a Parameters<'a>, ) -> Self

Build a new selector holding references to keyexpr and parameters Useful for printing pairs of keyexpr and parameters in URL-like format

pub fn into_owned(self) -> Selector<'static>

Convert this selector into an owned one.

Trait Implementations

impl<'a> Clone for Selector<'a>

fn clone(&self) -> Selector<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Selector<'_>

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

Formats the value using the given formatter.

impl Display for Selector<'_>

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

Formats the value using the given formatter.

impl<'a> From<&'a KeyExpr<'a>> for Selector<'a>

fn from(key_selector: &'a KeyExpr<'a>) -> Self

Converts to this type from the input type.

impl<'a> From<&'a OwnedKeyExpr> for Selector<'a>

fn from(key_selector: &'a OwnedKeyExpr) -> Self

Converts to this type from the input type.

impl<'a> From<&'a Query> for Selector<'a>

fn from(q: &'a Query) -> Self

Converts to this type from the input type.

impl<'a> From<&'a Selector<'a>> for (&'a KeyExpr<'a>, &'a Parameters<'a>)

fn from(selector: &'a Selector<'a>) -> Self

Converts to this type from the input type.

impl<'a> From<&Selector<'a>> for Selector<'a>

fn from(s: &Selector<'a>) -> Self

Converts to this type from the input type.

impl<'a> From<&'a keyexpr> for Selector<'a>

fn from(key_selector: &'a keyexpr) -> Self

Converts to this type from the input type.

impl<'a, K, P> From<(K, P)> for Selector<'a>

where K: Into<KeyExpr<'a>>, P: Into<Parameters<'a>>,

fn from((key_expr, parameters): (K, P)) -> Self

Converts to this type from the input type.

impl<'a> From<KeyExpr<'a>> for Selector<'a>

fn from(key_selector: KeyExpr<'a>) -> Self

Converts to this type from the input type.

impl From<OwnedKeyExpr> for Selector<'static>

fn from(key_selector: OwnedKeyExpr) -> Self

Converts to this type from the input type.

impl<'a> From<Selector<'a>> for (KeyExpr<'a>, Parameters<'a>)

fn from(selector: Selector<'a>) -> Self

Converts to this type from the input type.

impl FromStr for Selector<'static>

type Err = Box<dyn Error + Sync + Send>

The associated error which can be returned from parsing.

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

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

impl<'a> PartialEq for Selector<'a>

fn eq(&self, other: &Selector<'a>) -> 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<'a> TryFrom<&'a String> for Selector<'a>

type Error = Box<dyn Error + Sync + Send>

The type returned in the event of a conversion error.

fn try_from(s: &'a String) -> Result<Self, Self::Error>

Performs the conversion.

impl<'a> TryFrom<&'a str> for Selector<'a>

type Error = Box<dyn Error + Sync + Send>

The type returned in the event of a conversion error.

fn try_from(s: &'a str) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<String> for Selector<'_>

type Error = Box<dyn Error + Sync + Send>

The type returned in the event of a conversion error.

fn try_from(s: String) -> Result<Self, Self::Error>

Performs the conversion.

impl<'a> Eq for Selector<'a>

impl<'a> StructuralPartialEq for Selector<'a>