fn deserialize_variant()

in sgx_serialize_derive/src/decode.rs [132:224]

• 90 lines of code
• 3 McCabe index (conditional complexity)

fn deserialize_variant(
    cont: &Container,
    variant: &Variant,
    variant_index: usize
) -> Tokens {
    let this: syn::Ident = cont.ident.clone().into();
    let variant_ident = variant.ident.clone();

    let case = match variant.style {
        Style::Unit => {
            quote! {
                #variant_index => {
                    #this::#variant_ident
                }
            }
        }
        Style::Newtype => {
            quote! {
                #variant_index => {
                    #this::#variant_ident(match _d.read_enum_variant_arg(0usize, ::sgx_serialize::DeSerializable::decode) {
                            ::std::result::Result::Ok(__try_var) => __try_var,
                            ::std::result::Result::Err(__try_var) => {
                                return ::std::result::Result::Err(__try_var)
                            },
                    })
                }
            }
        }
        Style::Tuple => {
            let fileds_case: Vec<_> = variant.fields
                .iter()
                .enumerate()
                .map(
                    |(i, _)| -> _ {
                        quote! {
                            match _d.read_enum_variant_arg(#i, ::sgx_serialize::DeSerializable::decode) {
                                ::std::result::Result::Ok(__try_var) => __try_var,
                                ::std::result::Result::Err(__try_var) =>
                                return ::std::result::Result::Err(__try_var),
                            }
                        }
                    }
                )
                .collect();

            quote! {
                #variant_index => {
                    #this::#variant_ident(
                        #(#fileds_case,)*
                    )
                }
            }
        }
        Style::Struct => {
            let fields = variant
                .fields
                .iter()
                .map(
                    |f| {
                        f.ident
                            .clone()
                            .expect("struct variant has unnamed fields")
                    },
                );
            let fileds_case: Vec<_> = variant.fields
                .iter()
                .enumerate()
                .map(
                    |(i, _)| -> _ {
                        quote! {
                            match _d.read_enum_variant_arg(#i, ::sgx_serialize::DeSerializable::decode) {
                                ::std::result::Result::Ok(__try_var) => __try_var,
                                ::std::result::Result::Err(__try_var) =>
                                return ::std::result::Result::Err(__try_var),
                            }
                        }
                    }
                )
                .collect();
            quote! {
                #variant_index => {
                    #this::#variant_ident{
                        #(#fields: #fileds_case,)*
                    }
                }
            }
        }
    };

    quote! {
        #case
    }
}