Trait Visit

Source

pub trait Visit {
    // Required method
    fn visit(
        &mut self,
        name: &str,
        visitor: &mut Visitor,
    ) -> Result<(), VisitError>;
}

Expand description

Trait of types that can be read from a Visitor or written to a Visitor.

§Code Generation

Procedural macro could be used to generate trivial implementations for this trait, which covers 99% of the cases. Consider the following example:

use fyrox_core::visitor::prelude::*;

#[derive(Visit, Default)]
struct MyType {
    field_a: u32,
    field_b: String
}

The generated code will be something like this:

use fyrox_core::visitor::prelude::*;

struct MyType {
    field_a: u32,
    field_b: String
}

impl Visit for MyType {
    fn visit(&mut self, name: &str, visitor: &mut Visitor) -> VisitResult {
        let mut region = visitor.enter_region(name)?;

        self.field_a.visit("FieldA", &mut region)?;
        self.field_b.visit("FieldB", &mut region)?;

        Ok(())
    }
}

§Type Attributes

#[visit(optional)] - marks all the fields of the type as optional and suppresses any errors on serialization and deserialization. In the generated code, all the fields will be visited like this let _ = self.field_a.visit("FieldA", &mut region);
#[visit(pre_visit_method = "function_name")] - name of a function, that will be called before the generated body.
#[visit(post_visit_method = "function_name")] - name of a function, that will be called after the generated body.

§Field Attributes

#[visit(skip)] - disables serialization and deserialization of the field.
#[visit(rename = "new_name")] - overrides the name of the field with new_name. In the generated code, all the fields will be visited like this self.field_a.visit("new_name", &mut region)?;
#[visit(optional)] - marks the field as optional and suppresses any errors on serialization and deserialization. In the generated code, all the fields will be visited like this let _ = self.field_a.visit("FieldA", &mut region);

Required Methods§

Source

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

Read or write this value, depending on whether Visitor::is_reading() is true or false.

§In Write Mode

The given name is a key to identify where this value will be stored in the visitor. Whether this name indicates a field or a region is determined by the value being visited. No two regions can exist with the same name as children of a single node, and no two fields can exist with the same name within a single node, but a region may share the same name as a field. If a name clash occurs, then an error is returned. Otherwise the value is written into the Visitor data at the given name.

§In Read Mode

The given name is a key to identify where this value should be found the visitor. Whether the name indicates a field or a region is determined by the the value being visited. If the field or region is not found with the given name then an error is returned. Otherwise the value being visited will be mutated to match the data in the visitor.

§Buiding a Complex Value out of Multiple Fields

If representing this value requires more than one field, Visitor::enter_region can be used to create a new node within the visitor with the given name, and the fields of this value can then read from or write to that node using the returned Visitor without risk of name clashes.

See the documentation for the Visit derive macro for examples of how to implement Visit for some simple types.

§Abnormal Implementations

Types with special needs may choose to read and write in unusual ways. In addition to choosing whether they will store their data in a region or a field, a value might choose to do neither. A value may also choose to attempt to read its data in multiple ways so as to remain backwards-compatible with older versions where the format of data storage may be different.

See crate::variable::InheritableVariable::visit for an example of an abnormal implementation of Visit.

Visit

Trait Visit Copy item path

§Code Generation

§Type Attributes

§Field Attributes

Required Methods§

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

§In Write Mode

§In Read Mode

§Buiding a Complex Value out of Multiple Fields

§Abnormal Implementations

Implementations on Foreign Types§

impl Visit for bool

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for char

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for f32

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for f64

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for i8

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for i16

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for i32

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for i64

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for isize

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for u8

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for u16

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for u32

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for u64

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for usize

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for String

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for PathBuf

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for GenericBuffer

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for StreamingBuffer

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for SoundContext

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for State

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for State

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for Listener

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl Visit for SoundSource

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<K, S> Visit for HashSet<K, S>where K: Visit + Default + Clone + Hash + Eq, S: BuildHasher + Clone,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<K, V, S> Visit for HashMap<K, V, S>where K: Visit + Default + Clone + Hash + Eq, V: Visit + Default, S: BuildHasher + Clone,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for Option<T>where T: Default + Visit + 'static,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for Box<T>where T: Visit,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for Rc<T>where T: Visit + 'static,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for Weak<T>where T: Default + Visit + Any,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for Arc<T>where T: Visit + Send + Sync + Any,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for Weak<T>where T: Default + Visit + Send + Sync + 'static,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for Vec<T>where T: Default + Visit + 'static,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for Cell<T>where T: Copy + Clone + Visit + 'static,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

impl<T> Visit for RefCell<T>where T: Visit + 'static,

fn visit(&mut self, name: &str, visitor: &mut Visitor) -> Result<(), VisitError>

Trait Visit

impl<K, S> Visit for HashSet<K, S>
where K: Visit + Default + Clone + Hash + Eq, S: BuildHasher + Clone,

impl<K, V, S> Visit for HashMap<K, V, S>
where K: Visit + Default + Clone + Hash + Eq, V: Visit + Default, S: BuildHasher + Clone,

impl<T> Visit for Option<T>
where T: Default + Visit + 'static,

impl<T> Visit for Box<T>
where T: Visit,

impl<T> Visit for Rc<T>
where T: Visit + 'static,

impl<T> Visit for Weak<T>
where T: Default + Visit + Any,

impl<T> Visit for Arc<T>
where T: Visit + Send + Sync + Any,

impl<T> Visit for Weak<T>
where T: Default + Visit + Send + Sync + 'static,

impl<T> Visit for Vec<T>
where T: Default + Visit + 'static,

impl<T> Visit for Cell<T>
where T: Copy + Clone + Visit + 'static,

impl<T> Visit for RefCell<T>
where T: Visit + 'static,

impl<T> Visit for Range<T>
where T: Visit,

impl<T> Visit for Mutex<T>
where T: Visit + Send,

impl<T> Visit for RwLock<T>
where T: Visit + Send,

impl<T, const SIZE: usize> Visit for [T; SIZE]
where T: Default + Visit,