Trait macro_tools::AttributeComponent

pub trait AttributeComponent
where
    Self: Sized,
{
    const KEYWORD: &'static str;

    // Required method
    fn from_meta(attr: &Attribute) -> Result<Self>;
}

Trait for components of a structure aggregating attributes that can be constructed from a meta attribute.

The AttributeComponent trait defines the interface for components that can be created from a syn::Attribute meta item. Implementors of this trait are required to define a constant KEYWORD that identifies the type of the component and a method from_meta that handles the construction of the component from the given attribute.

This trait is designed to facilitate modular and reusable parsing of attributes applied to structs, enums, or other constructs. By implementing this trait, you can create specific components from attributes and then aggregate these components into a larger structure.

Example

use macro_tools::{ AttributeComponent, Result };
use syn::{ Attribute, Error };

struct MyComponent;

impl AttributeComponent for MyComponent
{
  const KEYWORD : &'static str = "my_component";

  fn from_meta( attr : &Attribute ) -> Result<Self>
  {
    // Parsing logic here
    // Return Ok(MyComponent) if parsing is successful
    // Return Err(Error::new_spanned(attr, "error message")) if parsing fails
    Ok( MyComponent )
  }
}

Parameters

• attr : A reference to the syn::Attribute from which the component is to be constructed.

Returns

A Result containing the constructed component if successful, or an error if the parsing fails.

Required Associated Constants

const KEYWORD: &'static str

The keyword that identifies the component.

This constant is used to match the attribute to the corresponding component. Each implementor of this trait must provide a unique keyword for its type.

Required Methods

fn from_meta(attr: &Attribute) -> Result<Self>

Constructs the component from the given meta attribute.

This method is responsible for parsing the provided syn::Attribute and returning an instance of the component. If the attribute cannot be parsed into the component, an error should be returned.

Parameters

• attr : A reference to the syn::Attribute from which the component is to be constructed.

Returns

A Result containing the constructed component if successful, or an error if the parsing fails.

Object Safety

This trait is not object safe.

Implementors