1 use proc_macro2::TokenStream; 2 use quote::quote; 3 use syn::{Data, DeriveInput}; 4 5 use crate::helpers::{non_enum_error, HasStrumVariantProperties, HasTypeProperties}; 6 enum_variant_names_inner(ast: &DeriveInput) -> syn::Result<TokenStream>7pub fn enum_variant_names_inner(ast: &DeriveInput) -> syn::Result<TokenStream> { 8 let name = &ast.ident; 9 let gen = &ast.generics; 10 let (impl_generics, ty_generics, where_clause) = gen.split_for_impl(); 11 12 let variants = match &ast.data { 13 Data::Enum(v) => &v.variants, 14 _ => return Err(non_enum_error()), 15 }; 16 17 // Derives for the generated enum 18 let type_properties = ast.get_type_properties()?; 19 let strum_module_path = type_properties.crate_module_path(); 20 21 let names = variants 22 .iter() 23 .map(|v| { 24 let props = v.get_variant_properties()?; 25 Ok(props.get_preferred_name(type_properties.case_style)) 26 }) 27 .collect::<syn::Result<Vec<_>>>()?; 28 29 Ok(quote! { 30 impl #impl_generics #strum_module_path::VariantNames for #name #ty_generics #where_clause { 31 const VARIANTS: &'static [&'static str] = &[ #(#names),* ]; 32 } 33 }) 34 } 35