4 // ignore-cloudabi no std::fs
7 use std::io::{Read, self};
8 use std::num::ParseIntError;
11 fn on_method() -> Result<i32, ParseIntError> {
12 Ok("1".parse::<i32>()? + "2".parse::<i32>()?)
15 fn in_chain() -> Result<String, ParseIntError> {
16 Ok("3".parse::<i32>()?.to_string())
19 fn on_call() -> Result<i32, ParseIntError> {
20 fn parse<T: FromStr>(s: &str) -> Result<T, T::Err> {
27 fn nested() -> Result<i32, ParseIntError> {
28 Ok("5".parse::<i32>()?.to_string().parse()?)
31 fn on_path() -> Result<i32, ParseIntError> {
32 let x = "6".parse::<i32>();
37 fn on_macro() -> Result<i32, ParseIntError> {
42 Ok(id!("7".parse::<i32>())?)
45 fn on_parens() -> Result<i32, ParseIntError> {
46 let x = "8".parse::<i32>();
51 fn on_block() -> Result<i32, ParseIntError> {
52 let x = "9".parse::<i32>();
57 fn on_field() -> Result<i32, ParseIntError> {
58 struct Pair<A, B> { a: A, b: B }
60 let x = Pair { a: "10".parse::<i32>(), b: 0 };
65 fn on_tuple_field() -> Result<i32, ParseIntError> {
66 let x = ("11".parse::<i32>(), 0);
71 fn on_try() -> Result<i32, ParseIntError> {
72 let x = "12".parse::<i32>().map(|i| i.to_string().parse::<i32>());
77 fn on_binary_op() -> Result<i32, ParseIntError> {
78 let x = 13 - "14".parse::<i32>()?;
79 let y = "15".parse::<i32>()? - 16;
80 let z = "17".parse::<i32>()? - "18".parse::<i32>()?;
85 fn on_index() -> Result<i32, ParseIntError> {
87 let y = "0".parse::<usize>();
92 fn on_args() -> Result<i32, ParseIntError> {
93 fn sub(x: i32, y: i32) -> i32 { x - y }
101 fn on_if() -> Result<i32, ParseIntError> {
109 fn on_if_let() -> Result<i32, ParseIntError> {
110 Ok(if let Ok(..) = "24".parse::<i32>() {
117 fn on_match() -> Result<i32, ParseIntError> {
118 Ok(match "27".parse::<i32>() {
119 Err(..) => "28".parse::<i32>(),
120 Ok(..) => "29".parse::<i32>(),
124 fn tight_binding() -> Result<bool, ()> {
125 fn ok<T>(x: T) -> Result<T, ()> { Ok(x) }
132 fn merge_error() -> Result<i32, Error> {
133 let mut s = String::new();
135 File::open("foo.txt")?.read_to_string(&mut s)?;
137 Ok(s.parse::<i32>()? + 1)
141 assert_eq!(Ok(3), on_method());
143 assert_eq!(Ok("3".to_string()), in_chain());
145 assert_eq!(Ok(4), on_call());
147 assert_eq!(Ok(5), nested());
149 assert_eq!(Ok(6), on_path());
151 assert_eq!(Ok(7), on_macro());
153 assert_eq!(Ok(8), on_parens());
155 assert_eq!(Ok(9), on_block());
157 assert_eq!(Ok(10), on_field());
159 assert_eq!(Ok(11), on_tuple_field());
161 assert_eq!(Ok(12), on_try());
163 assert_eq!(Ok(-3), on_binary_op());
165 assert_eq!(Ok(19), on_index());
167 assert_eq!(Ok(-1), on_args());
169 assert_eq!(Ok(22), on_if());
171 assert_eq!(Ok(25), on_if_let());
173 assert_eq!(Ok(29), on_match());
175 assert_eq!(Ok(false), tight_binding());
180 Parse(ParseIntError),
183 impl From<io::Error> for Error {
184 fn from(e: io::Error) -> Error {
189 impl From<ParseIntError> for Error {
190 fn from(e: ParseIntError) -> Error {