fn render_signature_arg()

in starlark_derive/src/render.rs [431:460]

• 25 lines of code
• 7 McCabe index (conditional complexity)

fn render_signature_arg(arg: &StarArg) -> TokenStream {
    let span = arg.span;

    let mut name_str_full = (if arg.by_ref { "$" } else { "" }).to_owned();
    name_str_full += &ident_string(&arg.name);
    let name_str = name_str_full.trim_matches('_');

    if arg.is_args() {
        assert!(arg.default.is_none(), "Can't have *args with a default");
        quote_spanned! { span=> __signature.args();}
    } else if arg.is_kwargs() {
        assert!(arg.default.is_none(), "Can't have **kwargs with a default");
        quote_spanned! { span=> __signature.kwargs();}
    } else if arg.is_this() {
        quote_spanned! { span=> }
    } else if arg.is_option() {
        quote_spanned! { span=> __signature.optional(#name_str);}
    } else if let Some(default) = &arg.default {
        // For things that are type Value, we put them on the frozen heap.
        // For things that aren't type value, use optional and then next_opt/unwrap
        // to avoid the to/from value conversion.
        if arg.is_value() {
            quote_spanned! { span=> __signature.defaulted(#name_str, globals_builder.alloc(#default));}
        } else {
            quote_spanned! { span=> __signature.optional(#name_str);}
        }
    } else {
        quote_spanned! { span=> __signature.required(#name_str);}
    }
}