extern crate lambda_calculus as lambda; use lambda::{parser::parse, term::Notation::Classic}; use std::error::Error; #[test] fn parse_error_question_mark_operator() { match using_question_mark_operator() { Result::Ok(_) => panic!("Should not be Ok"), Result::Err(e) => assert_eq!(e.to_string(), "syntax error; the expression is empty"), } } fn using_question_mark_operator() -> Result<(), Box> { parse("λλλ", Classic)?; Ok(()) }