Serdeio

Tiny IO utility library for Rust to serialize/deserialize Serde compatible structs

Install

cargo add serdeio

Serdeio supports JSON and JSON Lines formats. Additional formats are supported by enabling corresponding features.

• yaml
• csv

How to use

• read_record_from_reader is used to read a deserializable type T from std::io::Read. Data format must be specified by DataFormat enum.
• read_records_from_reader always tries to deserialize the data as Vec<T>.
• read_record_from_file accepts an AsRef<Path>. Data format is automatically determined by file extension.
• write_* functions follow the same rules as read_*.

Note that some data format like CSV and JSON Lines support only reading records Vec<T>.

Examples

The following code read a JSON file and parse it as Vec<User>. Then it encodes the data into YAML format and write it to STDOUT.

use anyhow::{anyhow, Context, Result as AnyResult};
use serde::{Deserialize, Serialize};
use serdeio::{read_record_from_file, write_records_to_writer, DataFormat};

#[derive(Debug, Deserialize, Serialize)]
struct User {
    id: u32,
    name: String,
    items: Vec<String>,
}

pub fn main() -> AnyResult<()> {
    // get input file path from argv
    let args: Vec<String> = std::env::args().collect();
    let input_file_path = &args[1];

    // read json file to memory
    let users: Vec<User> = read_record_from_file(input_file_path)
        .context("Failed to read records from file")?;

    // write to stdout in json lines format
    let writer = std::io::stdout();
    write_records_to_writer(writer, DataFormat::JsonLines, &users).unwrap();

    Ok(())
}