use proc_macro::TokenStream;

use quote::quote;

use syn::{FnArg, GenericArgument, ItemFn, PathArguments, Type, parse_macro_input};

/// Creates a named rule wrapper function for tree-morph rules.

///

/// This macro transforms a rule function into a `NamedRule`.

/// by wrapping it in a `NamedRule`.

///

///  ```rust

/// use tree_morph::prelude::*;

/// use tree_morph_macros::named_rule;

/// use uniplate::Uniplate;

///

/// #[derive(Debug, Clone, PartialEq, Eq, Uniplate)]

/// #[uniplate()]

/// enum Expr {

///     # Add(Box<Expr>, Box<Expr>),

///    // Snip

/// }

///

/// struct Meta;

///

/// #[named_rule("CustomName")]

/// fn my_rule(_: &mut Commands<Expr, Meta>, expr: &Expr, _: &Meta) -> Option<Expr> {

///     /// rule implementation

///     # None

/// }

/// ```

///

/// The above function will be transformed into a `NamedRule` and

/// have its name set to "CustomName". If not specified, the name will simply be

/// the function identifier. In the above case it will be "my_rule".

///

/// The original function logic is preserved in a private helper function.

#[proc_macro_attribute]

    } else {

    };

    // Create a private helper function with the original implementation

        #helper_function

        #[allow(non_upper_case_globals)]

        #vis const #name: ::tree_morph::prelude::NamedRule<::tree_morph::prelude::RuleFn<#type_t, #type_m>> =

          ::tree_morph::prelude::NamedRule::new(#rule_name, #helper_name as ::tree_morph::prelude::RuleFn<#type_t, #type_m>);

    };

    };

    };

    };

    };

    };

    };