cloudiful-config

Small serde-based configuration helpers for the common app case:

• Read typed config from the platform-default user config directory.
• Create a missing config.toml from T::default().
• Apply optional environment variable overrides on top of the file.
• Save config back atomically as TOML.

For an app named stock, the default file path is:

• Linux and other XDG platforms: $XDG_CONFIG_HOME/stock/config.toml or ~/.config/stock/config.toml
• macOS: ~/Library/Application Support/stock/config.toml
• Windows: %APPDATA%\\stock\\config.toml

Install

[dependencies]
cloudiful-config = "0.5.0"

API

The public API is intentionally small:

• read(app_name, options)
• save(app_name, config)
• ReadOptions

Example:

use cloudiful_config::{ReadOptions, read, save};
use serde::{Deserialize, Serialize};

#[derive(Default, Deserialize, Serialize)]
struct AppConfig {
    port: u16,
    debug: bool,
}

let config: AppConfig = read("stock", None).unwrap();
let config: AppConfig = read("stock", Some(ReadOptions::with_env_prefix("STOCK_"))).unwrap();
save("stock", config).unwrap();

Environment variable rules

• Pass Some(ReadOptions::with_env_prefix("APP_")) to read(...) when you want env overrides.
• Keys must start with the configured prefix.
• The suffix after the prefix is lowercased before matching fields.
• __ creates nested objects.
• Values are parsed as JSON literals first.
• If JSON parsing fails, the raw value is treated as a string.
• Arrays must be provided as full JSON values such as ["a","b"].
• Array index syntax is not supported.