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ConfigSource

differential_engine::ports

Trait ConfigSource 

Source 
pub trait ConfigSource {
    // Required methods
    fn user_config_dir(&self) -> Option<PathBuf>;
    fn read(&self, path: &Path) -> Result<Option<String>, EngineError>;
    fn read_required(&self, path: &Path) -> Result<String, EngineError>;
}
Expand description

Where configuration comes from.

The engine decides WHICH files to look for, what precedence they have and what their absence means; this port only says where the user’s config directory is and hands back file contents.

Required Methods§

Source

fn user_config_dir(&self) -> Option<PathBuf>

The user config directory. None when no home directory can be determined — then the user file simply does not exist.

Source

fn read(&self, path: &Path) -> Result<Option<String>, EngineError>

Contents, or None when the file does not exist. Any other failure (permissions, non-UTF-8) is an error.

Source

fn read_required(&self, path: &Path) -> Result<String, EngineError>

Contents of a file the caller named explicitly, where absence is a hard error rather than a default.

A separate method rather than the domain synthesising the message from read’s None, so the error text comes from the same std::fs call it always did and cannot drift.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§