Crate csv_legacy 

A lightweight CSV parser and writer, compatible with no_std environments.

Quick start

use csv_legacy::Reader;

let data = b"name,age\nAlice,30\nBob,25\n";
let mut sum = 0u32;

for result in Reader::new(data).rows() {
    let row = result?;
    // Access raw fields (including surrounding quotes) via indexing
    let name = &row[0];  // &str
    // Or via get_raw
    if let Some(name) = row.get_raw(0) {
        // name: &str
    }
}

Rows are yielded via Reader::rows, which returns an iterator over Row values. Each Row owns its data and can outlive the reader.

Streaming from std::io::Read

With the std feature (enabled by default), you can stream CSV data from any std::io::Read source without loading the entire input:

let file = File::open("data.csv")?;
for result in Reader::from_reader(file).rows() {
    let row = result?;
    // ...
}

Unescaped fields

Use Row::fields to iterate over unescaped fields (quotes stripped, "" resolved):

let data = b"\"hello\",\"foo\"\"bar\"\n";
for result in Reader::new(data).rows() {
    let row = result?;
    let fields: Vec<String> = row.fields().map(|f| f.into_owned()).collect();
    // fields: ["hello", "foo\"bar"]
}

Writing CSV

The Writer (requires std) writes CSV data to any std::io::Write sink, automatically quoting fields that contain delimiters, quotes, or newlines:

let mut w = Writer::new(Vec::new());
w.write_row(["name", "age", "city"])?;
w.write_row(["Alice", "30", "New York, NY"])?;
let bytes = w.into_inner()?;

Feature flags

Flag	Default	Description
std	on	Enables From<std::io::Error>, Writer, and Reader::from_reader.

Errors

Parsing errors are surfaced per row via ReadError. The error includes the line number and kind (unterminated quote, trailing content after a quoted field, invalid UTF-8, or I/O error).

no_std support

Disable default features to use the crate in a no_std environment. The crate still requires alloc for its internal buffers.

Structs

Fields

Iterator over unescaped fields in a Row, yielding Cow<str>.

ReadError

Errors that can occur when reading CSV data.

Reader

Parses CSV data from a byte slice or a std::io::Read source.

Row

A single row of CSV data.

RowIntoIter

An owning iterator over raw field strings in a Row.

Rows

An iterator over the rows of a CSV reader.

Writer

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

Enums

ReadErrorKind

Kinds of errors that can occur when reading CSV data.

WriteError

Errors that can occur when writing CSV data.