Struct Describer

pub struct Describer { /* private fields */ }

Describer holds descriptions of files and directories.

Types of Descriptions

• Specific description: A string mapped to a path describing a file or directory. When describe is called this will be retrieved as is.
• Pattern description: A string mapped to a directory’s path describing a child of the directory. When description of a child is wanted, the pattern is retrieved. In patterns, a wildcard is interpreted as a place holder for child’s name, and are replaced by the name when retreived.

If a string can be described using both a pattern and a specific description, the specific description will be favoured.

Examples

// Create a mutable describer.
let mut describer = def::Describer::new();

// Map a description to a given path.
describer.add_description("path/to/directory", "This is an empty directory.");

// Map a pattern to a given path. The pattern applies to the path's
// children. "*" works as a placeholder and will be replaced by the
// child's name.
describer.add_pattern("parent/directory", "* is a child of parent/directory.");

// The description is retrieved as is.
assert_eq!(
    describer.describe("path/to/directory"),
    Some("This is an empty directory.".to_string())
);

// "*" is replaced with "test".
assert_eq!(
    describer.describe("parent/directory/test"),
    Some("test is a child of parent/directory.".to_string())
);

// Despite having a pattern mapped to it, the pattern only applies to
// its children.
assert_eq!(describer.describe("parent/directory"), None);

Implementations

impl Describer

pub fn new() -> Describer

Create and return a new empty describer.

pub fn new_with( d: HashMap<String, String>, p: HashMap<String, String>, ) -> Describer

Create and return a new describer using given HashMaps.

Arguments

• d - A map of descriptions.
• p - A map of patterns.

pub fn new_from_json(json: &str) -> Result<Describer, Error>

Create and return a new describer using the given JSON value.

Arguments

• json - A string representing a JSON value that can be deserialized into a Describer. An error is returned if the JSON string can’t be deserialized.

pub fn describe(&self, path: &str) -> Option<String>

Return a description of the given path or None if no description exists. The descriptions map is checked for a description first, if none is found, then the patterns map is checked.

pub fn add_description(&mut self, path: &str, desc: &str)

Add a description to the descriptions map.

pub fn add_pattern(&mut self, path: &str, desc: &str)

Add a pattern to the patterns map.

pub fn to_json(&self, pretty: bool) -> Result<String, Error>

Return a string JSON representation of this Describer. This is subsequently written to a file to be re-loaded on next run.

Arguments

• pretty - If true, return a “pretty” JSON string.

Trait Implementations

impl Debug for Describer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Describer

fn default() -> Describer

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Describer

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Describer

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.