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>7 pub 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