我用一个声明性宏嵌套调用其他程序性宏，从arr![1_u32;2]到arr_proc([1_u32;2])。我不想直接调用arr_proc!。但我可能有一些错误，当我编译生 rust 的代码。编译器似乎有时无法展开所有宏。
我的proc宏：

#[proc_macro]
pub fn arr_proc(input: TokenStream) -> TokenStream {
    let repeat_expr: ExprRepeat = parse(input)
        .expect("Like arr!([Test::default(); 16])");

    let mut len = 0;
    // get length from repeat_expr
    if let Expr::Lit(expr_lit) = repeat_expr.len.deref() {
        if let Lit::Int(int_lit) = &expr_lit.lit {
            len = int_lit.base10_parse::<usize>().expect("Failed to parse integer literal");
        }
    }
    // parse and concat
    let _expr = repeat_expr.expr;
    // 1. generate the arr
    let mut _all = quote!();
    for _i in 0..len {
        // 2. append element into arr
        _all = quote! { #_all #_expr, };
    }
    // 3. add []
    let arr = quote! { [ #_all ] };
    return arr.into();
}

我的声明性宏：

#[macro_export]
macro_rules! arr {
    ($ele:expr; $repeat:literal) => {
        custom_proc_macro::arr_proc!([$ele; $repeat])
    };
}

我的测试用例：

#[test]
fn test_arr_() {
    let a: [u32; 2] = arr![1_u32;2];
    dbg!(a);
}

错误是：

error[E0308]: mismatched types
  --> tests/custom_proc_macro_test.rs:48:23
   |
48 |     let a: [u32; 2] = arr![1_u32;2];
   |            --------   ^^^^^^^^^^^^^ expected an array with a fixed size of 2 elements, found one with 0 elements
   |            |     |
   |            |     help: consider specifying the actual array length: `0`
   |            expected due to this
   |
   = note: expected array `[u32; 2]`
              found array `[_; 0]`
   = note: this error originates in the macro `custom_proc_macro::arr_proc` which comes from the expansion of the macro `arr` (in Nightly builds, run with -Z macro-backtrace for more info)
The meaning probably the compiler expanded the declarative macro and did not expand the proc macro.

我怎么能这样用呢？它能工作吗？