Trait Visitor 

pub trait Visitor: Sized + Sealed {
    type Result;
    type ListVisitor: ListVisitor<Result = Self::Result>;
    type AssocVisitor: AssocVisitor<Result = Self::Result>;

    // Required methods
    fn var_name(&self) -> VarName<'_>;
    fn purpose(&self) -> VisitPurpose;
    fn visit_undefined(self) -> Self::Result;
    fn visit_string<T: Display>(self, v: T) -> Self::Result;
    fn visit_list(self) -> Self::ListVisitor;
    fn visit_assoc(self) -> Self::AssocVisitor;

    // Provided methods
    fn visit_list_direct<I, T>(self, items: I) -> Self::Result
       where I: IntoIterator<Item = T>,
             T: Display { ... }
    fn visit_assoc_direct<I, K, T>(self, entries: I) -> Self::Result
       where I: IntoIterator<Item = (K, T)>,
             K: Display,
             T: Display { ... }
}

Variable visitor.

See the module documentation for usage.

Required Associated Types

type Result

Result of the visit.

type ListVisitor: ListVisitor<Result = Self::Result>

List visitor.

type AssocVisitor: AssocVisitor<Result = Self::Result>

Associative array visitor.

Required Methods

fn var_name(&self) -> VarName<'_>

Returns the name of the variable to visit.

fn purpose(&self) -> VisitPurpose

Returns the purpose of the visit.

The template expansion algorithm checks the types for some variables depending on its usage. To get the usage count correctly, you should only count visits with VisitPurpose::Expand.

If you need to know whether the variable is accessed and does not need dynamic context generation or access counts, consider using UriTemplateStr::variables method to iterate the variables in the URI template.

fn visit_undefined(self) -> Self::Result

Visits an undefined variable, i.e. indicates that the requested variable is unavailable.

fn visit_string<T: Display>(self, v: T) -> Self::Result

Visits a string variable.

fn visit_list(self) -> Self::ListVisitor

Visits a list variable.

If all the items are in a single iterable value, you can use visit_list_direct instead for convenience.

fn visit_assoc(self) -> Self::AssocVisitor

Visits an associative array variable.

If all the entries are in a single iterable value, you can use visit_assoc_direct instead for convenience.

Provided Methods

fn visit_list_direct<I, T>(self, items: I) -> Self::Result

where I: IntoIterator<Item = T>, T: Display,

Visits just a single list and finishes the visit right away.

fn visit_assoc_direct<I, K, T>(self, entries: I) -> Self::Result

where I: IntoIterator<Item = (K, T)>, K: Display, T: Display,

Visits just a single associative array and finishes the visit right away.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors