Struct ObjectSetSelector 

pub struct ObjectSetSelector<Field>(/* private fields */);

Available on crate feature parse2 only.

Helper type that allows us to select an impl of ObjectSetMethods

For use by macros.

See the module-level docs, and Field type in ItemValueParseable.

Example

The code in the (derive) macro output is roughly like this:

use tor_netdoc::parse2::multiplicity::{ObjectSetSelector, ObjectSetMethods as _};
use tor_netdoc::parse2::ItemStream;
let doc = "intro-item\n-----BEGIN OBJECT-----\naGVsbG8=\n-----END OBJECT-----\n";
let mut items = ItemStream::new(doc).unwrap();
let mut item = items.next().unwrap().unwrap();

let selector = ObjectSetSelector::<Option<String>>::default();
let obj = item.object().map(|obj| {
    let data = obj.decode_data().unwrap();
    String::from_utf8(data)
}).transpose().unwrap();
let obj = selector.resolve_option(obj).unwrap();
assert_eq!(obj, Some("hello".to_owned()));

Trait Implementations

impl<Field> Clone for ObjectSetSelector<Field>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<Field> Default for ObjectSetSelector<Field>

fn default() -> Self

Returns the “default value” for a type.

impl<T> ObjectSetMethods for &ObjectSetSelector<T>

type Field = T

The output type: the type of the field in the Item struct.

type Each = T

The value for each Item.

fn resolve_option(self, found: Option<Self::Each>) -> Result<Self::Field, EP>

Parse zero or more argument(s) into Self::Field.

fn check_label(self, label: &str) -> Result<(), EP>

where Self::Each: ItemObjectParseable,

If the contained type is ItemObjectParseable, call its check_label

fn check_object_parseable(self)

where Self::Each: ItemObjectParseable,

Check that the contained type can be parsed as an object

impl<T> ObjectSetMethods for ObjectSetSelector<Option<T>>

type Field = Option<T>

The output type: the type of the field in the Item struct.

type Each = T

The value for each Item.

fn resolve_option(self, found: Option<Self::Each>) -> Result<Self::Field, EP>

Parse zero or more argument(s) into Self::Field.

fn check_label(self, label: &str) -> Result<(), EP>

where Self::Each: ItemObjectParseable,

If the contained type is ItemObjectParseable, call its check_label

fn check_object_parseable(self)

where Self::Each: ItemObjectParseable,

Check that the contained type can be parsed as an object

impl<Field> Copy for ObjectSetSelector<Field>