Struct CsvWriter 

pub struct CsvWriter { /* private fields */ }

Builds CSV text one record at a time.

Output is deterministic: a field is quoted only when it contains a delimiter (,), a quote ("), or a line break (\r/\n); an embedded quote is doubled; and every record is terminated with \r\n (per RFC 4180). In-memory writing cannot fail.

use reliakit_csv::CsvWriter;

let mut writer = CsvWriter::new();
writer.write_record(["id", "note"]);
writer.write_record(["1", "has \"quotes\""]);
assert_eq!(writer.into_string(), "id,note\r\n1,\"has \"\"quotes\"\"\"\r\n");

Implementations

impl CsvWriter

pub const fn new() -> Self

Creates an empty writer.

Examples found in repository

examples/basic.rs (line 48)

fn main() {
    // Low-level: parse rows of strings.
    let rows = read_str("a,b\n1,2\n").unwrap();
    println!("rows: {rows:?}");

    // Low-level: write rows deterministically (a field is quoted only if needed).
    let mut writer = CsvWriter::new();
    writer.write_record(["plain", "needs,quote"]);
    print!("written: {}", writer.into_string());

    // Typed: round-trip a slice of records through a header + rows.
    let services = vec![
        Service {
            name: "api".into(),
            port: 8080,
            enabled: true,
        },
        Service {
            name: "worker, west".into(),
            port: 9000,
            enabled: false,
        },
    ];
    let text = to_csv_string(&services);
    print!("encoded:\n{text}");

    let decoded: Vec<Service> = from_csv_str(&text).unwrap();
    assert_eq!(decoded, services);
    println!("round-trip ok: {} record(s)", decoded.len());
}

pub fn write_record<I, S>(&mut self, fields: I)

where I: IntoIterator<Item = S>, S: AsRef<str>,

Writes one record from an iterator of field values, terminated by \r\n.

Examples found in repository

examples/basic.rs (line 49)

fn main() {
    // Low-level: parse rows of strings.
    let rows = read_str("a,b\n1,2\n").unwrap();
    println!("rows: {rows:?}");

    // Low-level: write rows deterministically (a field is quoted only if needed).
    let mut writer = CsvWriter::new();
    writer.write_record(["plain", "needs,quote"]);
    print!("written: {}", writer.into_string());

    // Typed: round-trip a slice of records through a header + rows.
    let services = vec![
        Service {
            name: "api".into(),
            port: 8080,
            enabled: true,
        },
        Service {
            name: "worker, west".into(),
            port: 9000,
            enabled: false,
        },
    ];
    let text = to_csv_string(&services);
    print!("encoded:\n{text}");

    let decoded: Vec<Service> = from_csv_str(&text).unwrap();
    assert_eq!(decoded, services);
    println!("round-trip ok: {} record(s)", decoded.len());
}

pub fn len(&self) -> usize

Returns the number of bytes written so far.

pub fn is_empty(&self) -> bool

Returns true if no records have been written.

pub fn as_str(&self) -> &str

Returns a borrowed view of the CSV written so far.

pub fn into_string(self) -> String

Consumes the writer and returns the CSV text.

Examples found in repository

examples/basic.rs (line 50)

fn main() {
    // Low-level: parse rows of strings.
    let rows = read_str("a,b\n1,2\n").unwrap();
    println!("rows: {rows:?}");

    // Low-level: write rows deterministically (a field is quoted only if needed).
    let mut writer = CsvWriter::new();
    writer.write_record(["plain", "needs,quote"]);
    print!("written: {}", writer.into_string());

    // Typed: round-trip a slice of records through a header + rows.
    let services = vec![
        Service {
            name: "api".into(),
            port: 8080,
            enabled: true,
        },
        Service {
            name: "worker, west".into(),
            port: 9000,
            enabled: false,
        },
    ];
    let text = to_csv_string(&services);
    print!("encoded:\n{text}");

    let decoded: Vec<Service> = from_csv_str(&text).unwrap();
    assert_eq!(decoded, services);
    println!("round-trip ok: {} record(s)", decoded.len());
}

Trait Implementations

impl Clone for CsvWriter

fn clone(&self) -> CsvWriter

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CsvWriter

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for CsvWriter

fn default() -> CsvWriter

Returns the “default value” for a type.