18 unstable releases (7 breaking)
0.9.0 | Apr 25, 2022 |
---|---|
0.7.0 | Nov 10, 2021 |
0.5.2 | May 19, 2021 |
0.5.1 | Mar 10, 2021 |
0.3.0 | Mar 7, 2019 |
#18 in #strict
770 downloads per month
Used in 11 crates
(8 directly)
180KB
4K
SLoC
HOCON.rs
The API docs for the master branch are published here.
Parse HOCON configuration files in Rust following the HOCON Specifications.
This implementation goal is to be as permissive as possible, returning a valid document
with all errors wrapped in Hocon::BadValue
. strict
mode can be enabled to return the
first Error
encountered instead.
Examples
Parsing a string to a struct using serde
use serde::Deserialize;
#[derive(Deserialize)]
struct Configuration {
host: String,
port: u8,
auto_connect: bool,
}
fn main() -> Result<(), Error> {
let s = r#"{
host: 127.0.0.1
port: 80
auto_connect: false
}"#;
let conf: Configuration = hocon::de::from_str(s)?;
Ok(())
}
Reading from a string and getting value directly
use hocon::HoconLoader;
fn main() -> Result<(), Error> {
let s = r#"{ a: 7 }"#;
let doc = HoconLoader::new()
.load_str(s)?
.hocon()?;
let a = doc["a"].as_i64();
assert_eq!(a, Some(7));
Ok(())
}
Deserializing to a struct using serde
use serde::Deserialize;
use hocon::HoconLoader;
#[derive(Deserialize)]
struct Configuration {
host: String,
port: u8,
auto_connect: bool,
}
fn main() -> Result<(), Error> {
let s = r#"{
host: 127.0.0.1
port: 80
auto_connect: false
}"#;
let conf: Configuration = HoconLoader::new()
.load_str(s)?
.resolve()?;
Ok(())
}
Reading from a file
use hocon::HoconLoader;
fn main() -> Result<(), Error> {
let doc = HoconLoader::new()
.load_file("tests/data/basic.conf")?
.hocon()?;
let a = doc["a"].as_i64();
assert_eq!(a, Some(5));
Ok(())
}
Reading from several documents
use hocon::HoconLoader;
fn main() -> Result<(), Error> {
let s = r#"{
a: will be changed
unchanged: original value
}"#;
let doc = HoconLoader::new()
.load_str(s)?
.load_file("tests/data/basic.conf")?
.hocon()?;
let a = doc["a"].as_i64();
assert_eq!(a, Some(5));
let unchanged = doc["unchanged"].as_string();
assert_eq!(unchanged, Some(String::from("original value")));
Ok(())
}
Features
All features are enabled by default. They can be disabled to reduce dependencies.
url-support
This feature enable fetching URLs in includes with include url("http://mydomain.com/myfile.conf")
(see
spec). If disabled,
includes will only load local files specified with include "path/to/file.conf"
or
include file("path/to/file.conf")
.
serde-support
This feature enable deserializing to a struct
implementing Deserialize
using serde
use serde::Deserialize;
use hocon::HoconLoader;
#[derive(Deserialize)]
struct Configuration {
host: String,
port: u8,
auto_connect: bool,
}
# fn main() -> Result<(), Error> {
let s = r#"{host: 127.0.0.1, port: 80, auto_connect: false}"#;
# #[cfg(feature = "serde-support")]
let conf: Configuration = HoconLoader::new().load_str(s)?.resolve()?;
# Ok(())
# }
Spec Coverage
https://github.com/lightbend/config/blob/master/HOCON.md
- parsing JSON
- comments
- omit root braces
- key-value separator
- commas are optional if newline is present
- whitespace
- duplicate keys and object merging
- unquoted strings
- multi-line strings
- value concatenation
- object concatenation
- array concatenation
- path expressions
- path as keys
- substitutions
- includes
- conversion of numerically-indexed objects to arrays
- allow URL for included files
- duration unit format
- period unit format
- size unit format
Dependencies
~7–20MB
~301K SLoC