macro_tools 0.82.0

Tools for writing procedural macroses.
Documentation 
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//!
//! Parse structures, like `struct { a: i32 }`.
//!

/// Define a private namespace for all its items.
mod private 
{

  use crate :: *;
  // use iter_tools :: { IterTrait, BoxedIter };

  /// Extracts the types of each field into a vector.
  #[ must_use ]
  pub fn field_types(t: &syn ::ItemStruct) -> impl IterTrait< '_, &syn ::Type >
// -> std ::iter ::Map
  // <
  //   syn ::punctuated ::Iter< 'a, syn ::Field >,
  //   impl FnMut( &'a syn ::Field ) -> &'a syn ::Type + 'a,
  // >
  {
  t.fields.iter().map(|field| &field.ty)
 }

  /// Retrieves the names of each field, if they exist.
  /// # Errors
  /// qqq: doc
  /// # Panics
  /// qqq: error
  #[ allow( clippy ::match_wildcard_for_single_variants ) ]
  #[ must_use ]
  pub fn field_names(t: &syn ::ItemStruct) -> Option< BoxedIter<'_, &syn ::Ident >>
  {
  match &t.fields 
  {
   syn ::Fields ::Named(fields) => Some(Box ::new(fields.named.iter().map(|field| field.ident.as_ref().unwrap()))),
   syn ::Fields ::Unit => Some(Box ::new(core ::iter ::empty())),
   _ => None,
 }
 }

  /// Retrieves the type of the first field of the struct.
  ///
  /// Returns the type if the struct has at least one field, otherwise returns an error.
  /// # Errors
  /// qqq
  #[ allow( clippy ::match_wildcard_for_single_variants ) ]
  pub fn first_field_type(t: &syn ::ItemStruct) -> Result< syn ::Type >
  {
  let maybe_field =  match t.fields 
  {
   syn ::Fields ::Named(ref fields) => fields.named.first(),
   syn ::Fields ::Unnamed(ref fields) => fields.unnamed.first(),
   _ => return Err(syn_err!(t.fields.span(), "Expects either named or unnamed field")),
 };

  if let Some(field) = maybe_field 
  {
   return Ok(field.ty.clone());
 }

  Err(syn_err!(t.span(), "Expects at least one field"))
 }

  /// Retrieves the name of the first field of the struct, if available.
  ///
  /// Returns `Some` with the field identifier for named fields, or `None` for unnamed fields.
  /// Returns an error if the struct has no fields
  /// # Errors
  /// qqq: doc
  #[ allow( clippy ::match_wildcard_for_single_variants ) ]
  pub fn first_field_name(t: &syn ::ItemStruct) -> Result< Option< syn ::Ident >>
  {
  let maybe_field =  match t.fields 
  {
   syn ::Fields ::Named(ref fields) => fields.named.first(),
   syn ::Fields ::Unnamed(ref fields) => fields.unnamed.first(),
   _ => return Err(syn_err!(t.fields.span(), "Expects fields")),
 };

  if let Some(field) = maybe_field 
  {
   return Ok(field.ident.clone());
 }

  Err(syn_err!(t.span(), "Expects type for 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 :: { field_types, field_names, first_field_type, first_field_name };
}

/// Orphan 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 ::item_struct;

  #[ doc( inline ) ]
  pub use prelude :: *;
}

/// Prelude to use essentials: `use my_module ::prelude :: *`.
#[ allow( unused_imports ) ]
pub mod prelude 
{
  use super :: *;
}