4 releases (breaking)
0.4.0 | Oct 31, 2022 |
---|---|
0.3.0 | Oct 30, 2022 |
0.2.0 | Oct 29, 2022 |
0.1.0 | Oct 28, 2022 |
#316 in Encoding
898 downloads per month
Used in varfish-server-worker
46KB
364 lines
GitHub | crates.io | Documentation | Issues | Changelog
JSON Lines (a.k.a. newline-delimited JSON) is a simple format for storing
sequences of JSON values in which each value is serialized on a single line and
terminated by a newline sequence. The serde-jsonlines
crate provides
functionality for reading & writing these documents (whether all at once or
line by line) using serde
's serialization & deserialization features.
Basic usage involves simply importing the BufReadExt
or WriteExt
extension
trait and then using the json_lines()
or write_json_lines()
method on a
BufRead
or Write
value to read or write a sequence of JSON Lines values.
Convenience functions are also provided for the common case of reading or
writing a JSON Lines file given as a filepath.
At a lower level, values can be read or written one at a time (which is useful
if, say, different lines are different types) by wrapping a BufRead
or
Write
value in a JsonLinesReader
or JsonLinesWriter
and then calling the
wrapped structure's read()
or write()
method, respectively.
When the async
feature is enabled, analogous types for working with JSON
Lines asynchronously under tokio
become available.
Installation
serde-jsonlines
requires version 1.56 of Rust or higher. To use the
serde-jsonlines
library in your Cargo project, add the following to your
Cargo.toml
:
[dependencies]
serde-jsonlines = "0.4.0"
Example
use serde::{Deserialize, Serialize};
use serde_jsonlines::{json_lines, write_json_lines};
use std::io::Result;
#[derive(Debug, Deserialize, Eq, PartialEq, Serialize)]
pub struct Structure {
pub name: String,
pub size: i32,
pub on: bool,
}
fn main() -> Result<()> {
let values = vec![
Structure {
name: "Foo Bar".into(),
size: 42,
on: true,
},
Structure {
name: "Quux".into(),
size: 23,
on: false,
},
Structure {
name: "Gnusto Cleesh".into(),
size: 17,
on: true,
},
];
write_json_lines("example.jsonl", &values)?;
let values2 = json_lines("example.jsonl")?.collect::<Result<Vec<Structure>>>()?;
assert_eq!(values, values2);
Ok(())
}
Dependencies
~0.4–5.5MB
~82K SLoC