Struct Writer 

pub struct Writer<W: Write> { /* private fields */ }

Writes CSV data to a std::io::Write sink.

Fields containing the delimiter, a newline, or a double-quote are automatically quoted. "" escape sequences are used for quotes within quoted fields.

Internal buffering is used to avoid many small writes. Callers should not wrap the writer in a BufWriter.

Example

use csv::Writer;

let mut w = Writer::new(Vec::new());
w.write_row(["name", "age", "city"])?;
w.write_row(["Alice", "30", "New York, NY"])?;
let result = String::from_utf8(w.into_inner()?).unwrap();
assert_eq!(result, "name,age,city\r\nAlice,30,\"New York, NY\"\r\n");

Implementations

impl<W: Write> Writer<W>

pub fn new(writer: W) -> Self

Create a new writer wrapping the given output sink.

The writer starts with default comma delimiter and strict field-count validation (all rows must have the same number of fields).

pub fn delimiter(&mut self, byte: u8) -> &mut Self

Set the field delimiter byte (default is ,).

use csv::Writer;
let mut w = Writer::new(Vec::new());
w.delimiter(b'\t');
w.write_row(["a", "b", "c"])?;

pub fn flexible(&mut self, yes: bool) -> &mut Self

Enable or disable the field count consistency check.

When false (default), all rows must have the same number of fields. When true, rows are allowed to vary in width.

pub fn write_row<I, T>(&mut self, row: I) -> Result<(), WriteError>

where I: IntoIterator<Item = T>, T: AsRef<[u8]>,

Write a single row.

Each element in the iterator is written as a CSV field. Fields are auto-quoted if they contain the delimiter, a newline (\n or \r), or a double-quote (").

Errors

Returns WriteError::InconsistentFieldCount if the number of fields differs from previous rows (unless flexible mode is enabled). Returns WriteError::Io if the underlying writer fails.

pub fn flush(&mut self) -> Result<(), WriteError>

Flush the internal buffer to the underlying writer.

pub fn into_inner(self) -> Result<W, WriteError>

Unwrap the writer, flushing any remaining data and returning the underlying writer.

Trait Implementations

impl<W: Write> Drop for Writer<W>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.