macro_tools 0.84.0

Tools for writing procedural macroses.
Documentation
//!
//! Macro helpers around derive macro and structure [`syn ::DeriveInput`].
//!

/// Define a private namespace for all its items.
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 );
  /// ```
  /// # Errors
  /// qqq: doc
  pub fn named_fields(ast: &syn ::DeriveInput) -> crate ::Result< &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 :: { };
}