You can use either the read!
macro to read a single value and return it, or
the scan!
macro to read one or more values into variables. Both macros can
also read from a file or from memory. The read!
macro can take any type that
implements Iterator<Item=u8>
as an optional third argument, and the scan!
macro's arguments can be prefixed with iter =>
where iter
implements
Iterator<Item=u8>
.
Examples
scan! macro
use text_io::scan;
// reading from a string source
let i: i32;
scan!("<b>12</b>".bytes() => "<b>{}</b>", i);
assert_eq!(i, 12);
// reading multiple values from stdio
let a: i32;
let b: &mut u8 = &mut 5;
scan!("{}, {}", a, *b);
read! macro
use text_io::read;
// read until a whitespace and try to convert what was read into an i32
let i: i32 = read!();
// read until a whitespace (but not including it)
let word: String = read!(); // same as read!("{}")
// read until a newline (but not including it)
let line: String = read!("{}\n");
// expect the input "<b><i>" or panic
// read until the next "<" and return that.
// expect the input "/i></b>"
let stuff: String = read!("<b><i>{}</i></b>");
// reading from files
use std::io::Read;
let mut file = std::fs::File::open("tests/answer.txt").unwrap().bytes().map(|ch| ch.unwrap());
let val: i32 = read!("The answer is {}!!!11einself\n", file);
// reading from strings
let val: i32 = read!("Number: {}", "Number: 99".bytes());