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What is Uclicious

Uclicious is a flexible reduced boilerplate configuration framework.

Uclicious is built on top of libucl. If you ever wrote an nginx configurtion and though "Damn, I wish all configuration files were like this" this is the library for you. Internal parser supports both: nginx-like and json-like formats. JSON parser is a little bit more permissive than - every json file is a valid UCL file, but not other way around. It is much more complex than json or TOML, so I recommend reading documentaiton about it. Author of UCL did a great job documenting it. This library provides both: derive-driven and raw-api driven usage patterns.

Usage

Raw API

Raw API involves interacting with libucl parser via safe api:

use uclicious::*;
let mut parser = Parser::default();
let input = r#"
test_string = "no scope"
a_float = 3.14
an_integer = 69420
is_it_good = yes
buffer_size = 1KB
interval = 1s
"#;
parser.add_chunk_full(input, Priority::default(), DEFAULT_DUPLICATE_STRATEGY).unwrap();
let result = parser.get_object().unwrap();

let lookup_result = result.lookup("test_string").unwrap().as_string().unwrap();
assert_eq!(lookup_result.as_str(), "no scope");

let lookup_result = result.lookup("a_float").unwrap().as_f64().unwrap();
assert_eq!(lookup_result, 3.14f64);

let lookup_result = result.lookup("an_integer").unwrap().as_i64().unwrap();
assert_eq!(lookup_result, 69420i64);

let lookup_result = result.lookup("is_it_good").unwrap().as_bool().unwrap();
assert_eq!(lookup_result, true);

let lookup_result = result.lookup("buffer_size").unwrap().as_i64().unwrap();
assert_eq!(lookup_result, 1024);
let lookup_result = result.lookup("interval").unwrap().as_time().unwrap();
assert_eq!(lookup_result, 1.0f64);

In order to get around rust rules library implemets its own trait FromObject for some basic types:

use uclicious::*;
let mut parser = Parser::default();
let input = r#"
test_string = "no scope"
a_float = 3.14
an_integer = 69420
is_it_good = yes
buffer_size = 1KB
"#;
parser.add_chunk_full(input, Priority::default(), DEFAULT_DUPLICATE_STRATEGY).unwrap();
let result = parser.get_object().unwrap();

let lookup_result = result.lookup("is_it_good").unwrap();
let maybe: Option<bool> = FromObject::try_from(lookup_result).unwrap();
assert_eq!(Some(true), maybe);

Derive-driven

On top of "raw" interface to libUCL, Uclicious provides an easy way to derive constructor for strucs:

use uclicious::*;
use std::path::PathBuf;
use std::net::SocketAddr;
use std::collections::HashMap;
use std::time::Duration;

#[derive(Debug,Uclicious)]
#[ucl(var(name = "test", value = "works"))]
struct Connection {
   #[ucl(default)]
   enabled: bool,
   host: String,
   #[ucl(default = "420")]
   port: i64,
   buffer: u64,
   #[ucl(path = "type")]
   kind: String,
   locations: Vec<PathBuf>,
   addr: SocketAddr,
   extra: Extra,
   #[ucl(path = "subsection.host")]
   hosts: Vec<String>,
   #[ucl(default)]
   option: Option<String>,
   gates: HashMap<String, bool>,
   interval: Duration,
}

#[derive(Debug,Uclicious)]
#[ucl(skip_builder)]
struct Extra {
   enabled: bool
}
let mut builder = Connection::builder().unwrap();

let input = r#"
    enabled = yes
    host = "some.fake.url"
    buffer = 1mb
    type = $test
    locations = "/etc/"
    addr = "127.0.0.1:80"
    extra = {
       enabled = on
   }
    subsection {
       host = [host1, host2]
   }
   interval = 10ms
   gates {
        feature_1 = on
        feature_2 = off
        feature_3 = on
   }"#;

builder.add_chunk_full(input, Priority::default(), DEFAULT_DUPLICATE_STRATEGY).unwrap();
let connection: Connection = builder.build().unwrap();

If you choose to derive builder then ::builder() method will be added to target struct.

Validators

Library supports running optional validators on values before building the resulting struct:

use uclicious::*;
mod validators {
   use uclicious::ObjectError;
    pub fn is_positive(lookup_path: &str, value: &i64) -> Result<(), ObjectError> {
        if *value > 0 {
            Ok(())
        } else {
            Err(ObjectError::other(format!("{} is not a positive number", lookup_path)))
        }
    }
}
#[derive(Debug,Uclicious)]
struct Validated {
   #[ucl(default, validate="validators::is_positive")]
    number: i64
}
let mut builder = Validated::builder().unwrap();

let input = "number = -1";
builder.add_chunk_full(input, Priority::default(), DEFAULT_DUPLICATE_STRATEGY).unwrap();
assert!(builder.build().is_err())

Type Mapping

If your target structure has types that don't implement FromObject you can use From or TryFrom via intermediate that does:

use uclicious::*;
use std::convert::{From,TryFrom};

#[derive(Debug, Eq, PartialEq)]
enum Mode {
    On,
    Off,
}

impl TryFrom<String> for Mode {
    type Error = ObjectError;
    fn try_from(src: String) -> Result<Mode, ObjectError> {
        match src.to_lowercase().as_str() {
            "on" => Ok(Mode::On),
            "off" => Ok(Mode::Off),
            _   => Err(ObjectError::other(format!("{} is not supported value", src)))
        }
    }
}

#[derive(Debug, Eq, PartialEq)]
struct WrappedInt(i64);

impl From<i64> for WrappedInt {
    fn from(src: i64) -> WrappedInt {
        WrappedInt(src)
    }
}

#[derive(Debug,Uclicious, Eq, PartialEq)]
struct Mapped {
   #[ucl(from="i64")]
    number: WrappedInt,
   #[ucl(try_from="String")]
    mode: Mode
}
let mut builder = Mapped::builder().unwrap();

let input = r#"
    number = -1,
    mode = "on"
"#;
builder.add_chunk_full(input, Priority::default(), DEFAULT_DUPLICATE_STRATEGY).unwrap();
let actual = builder.build().unwrap();
let expected = Mapped {
number: WrappedInt(-1),
mode: Mode::On
};
assert_eq!(expected, actual);

Additionally you can provide mapping to your type from ObjectRef:

use uclicious::*;

#[derive(Debug, Eq, PartialEq)]
pub enum Mode {
    On,
    Off,
}

pub fn map_bool(src: ObjectRef) -> Result<Mode, ObjectError> {
    let bool: bool = src.try_into()?;
    if bool {
        Ok(Mode::On)
    } else {
        Ok(Mode::Off)
    }
}
#[derive(Debug,Uclicious, Eq, PartialEq)]
struct Mapped {
   #[ucl(map="map_bool")]
    mode: Mode
}
let mut builder = Mapped::builder().unwrap();

let input = r#"
    mode = on
"#;
builder.add_chunk_full(input, Priority::default(), DEFAULT_DUPLICATE_STRATEGY).unwrap();
let actual = builder.build().unwrap();
let expected = Mapped {
    mode: Mode::On
};

Supported attributes (#[ucl(..)])

Structure level

Field level

All field level options are optional.

Additional notes

Contributing

PRs, feature requests, bug reports are welcome. I won't be adding CoC — be civilized.

Particular Contributions of Interest

Goals

Not Goals

Special thanks

LICENSE

BSD-2-Clause.

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