extern crate proc_macro2; extern crate syn; use std::str::FromStr; use proc_macro2::TokenStream; use syn::{Expr, ExprRange}; #[test] fn test_expr_parse() { let code = "..100u32"; let tt = TokenStream::from_str(code).unwrap(); let expr: Expr = syn::parse2(tt.clone()).unwrap(); let expr_range: ExprRange = syn::parse2(tt).unwrap(); assert_eq!(expr, Expr::Range(expr_range)); }