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//!
//! Macro helpers around derive macro and structure [`syn::DeriveInput`].
//!
/// Internal namespace.
pub( crate ) mod private
{
use crate::*;
use syn::punctuated::Punctuated;
///
/// Extracts the named fields from a struct defined in a `syn::DeriveInput`.
///
/// This function specifically handles `syn::DeriveInput` that represent structs
/// with named fields. It will return an error if the provided AST does not conform to these expectations.
///
/// # Example
///
/// ```rust, ignore
/// let ast = match syn::parse::< syn::DeriveInput >( input )
/// {
/// Ok( syntax_tree ) => syntax_tree,
/// Err( err ) => return Err( err ),
/// };
/// let fields = derive.named_fields( &ast );
/// ```
pub fn named_fields< 'a >( ast : &'a syn::DeriveInput ) -> crate::Result< &'a Punctuated< syn::Field, syn::token::Comma > >
{
let fields = match ast.data
{
syn::Data::Struct( ref data_struct ) => match data_struct.fields
{
syn::Fields::Named( ref fields_named ) =>
{
&fields_named.named
},
_ => return Err( syn_err!( ast, "Unknown format of data, expected syn::Fields::Named( ref fields_named )\n {}", qt!{ #ast } ) ),
},
_ => return Err( syn_err!( ast, "Unknown format of data, expected syn::Data::Struct( ref data_struct )\n {}", qt!{ #ast } ) ),
};
Ok( fields )
}
}
#[ doc( inline ) ]
#[ allow( unused_imports ) ]
pub use own::*;
/// Own namespace of the module.
#[ allow( unused_imports ) ]
pub mod own
{
use super::*;
#[ doc( inline ) ]
pub use orphan::*;
#[ doc( inline ) ]
pub use private::
{
named_fields,
};
}
/// Parented namespace of the module.
#[ allow( unused_imports ) ]
pub mod orphan
{
use super::*;
#[ doc( inline ) ]
pub use exposed::*;
}
/// Exposed namespace of the module.
#[ allow( unused_imports ) ]
pub mod exposed
{
use super::*;
pub use super::super::derive;
#[ doc( inline ) ]
pub use prelude::*;
#[ doc( inline ) ]
pub use private::
{
};
}
/// Prelude to use essentials: `use my_module::prelude::*`.
#[ allow( unused_imports ) ]
pub mod prelude
{
use super::*;
#[ doc( inline ) ]
pub use private::
{
};
}