Struct TokenReader

Source

pub struct TokenReader<R> { /* private fields */ }

Expand description

This struct wraps a BufReader to allow easy parsing of whitespace delimited files.

Implementations§

Source §

impl<R: BufRead> TokenReader<R>

Source

pub fn new(buf_read: R) -> Self

Creates a TokenReader from a type that implements BufRead, such as Stdin.

Source

pub fn line<T>(&mut self) -> Result<T, ReadTokensError<T::Error>>
where T: FromTokens,

Reads and parses a single line of whitespace delimited tokens.

§Examples

let mut input = TokenReader::new("James 158000 0.58".as_bytes());
let (name, points, win_chance): (String, u64, f64) = input.line()?;

assert_eq!(name, "James");
assert_eq!(points, 158000);
assert_eq!(win_chance, 0.58);

let mut input = TokenReader::new("13 8 17".as_bytes());
let numbers: Vec<i64> = input.line()?;

assert_eq!(numbers, vec![13, 8, 17]);

Source

pub fn line_raw(&mut self) -> Result<String, ReadLineError>

Reads a single line, unmodified.

§Example

let mut input = TokenReader::new("1. Write a parsing library in Rust.\n2. ???\n3. Profit!".as_bytes());
let line = input.line_raw()?;

assert_eq!(line, "1. Write a parsing library in Rust.");

Source

pub fn take<T>(&mut self, count: usize) -> Take<'_, T, R, usize> ⓘ
where T: FromTokens,

Creates an iterator that reads and parses a specific number of lines.

The line count must be an usize. You can also use TokenReader::take_count, which allows other types.

§Example

let mut input = TokenReader::new("1 a\n2 b\n3 c".as_bytes());
let lines: Vec<(u64, char)> = input.take(3).collect::<Result<_, _>>()?;

assert_eq!(lines, vec![(1, 'a'), (2, 'b'), (3, 'c')]);

Source

pub fn take_count<T, S>(&mut self, count: S) -> Take<'_, T, R, S> ⓘ
where T: FromTokens, S: LineCount,

Like TokenReader::take, but can use non-usize counts.

This method can use any type implementing LineCount as the element count, like u32. It can be used to process more than 2^32 lines on 32-bit systems.

§Example

let mut input = TokenReader::new("1 a\n2 b\n3 c".as_bytes());
let lines: Vec<(u64, char)> = input.take_count(3u64).collect::<Result<_, _>>()?;

assert_eq!(lines, vec![(1, 'a'), (2, 'b'), (3, 'c')]);