Struct ConfigPrefixView 

pub struct ConfigPrefixView<'a> { /* private fields */ }

Read-only prefix view over a Config: key lookups use a logical key prefix.

This type is named explicitly so other kinds of configuration views can be added later without overloading a generic ConfigView.

Lookups rewrite keys by prepending prefix, while exposing keys relative to that prefix.

Implementations

impl<'a> ConfigPrefixView<'a>

pub fn prefix(&self) -> &str

Gets the logical prefix of this view.

Returns

The normalized prefix string (no leading or trailing dot separators).

pub fn prefix_view(&self, prefix: &str) -> ConfigPrefixView<'a>

Creates a nested prefix view by appending prefix.

Parameters

• prefix - Segment to append (. is trimmed); empty keeps the current prefix.

Returns

A new view with the combined prefix.

Trait Implementations

impl<'a> Clone for ConfigPrefixView<'a>

fn clone(&self) -> ConfigPrefixView<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> ConfigReader for ConfigPrefixView<'a>

fn is_enable_variable_substitution(&self) -> bool

Returns whether ${...} variable substitution is applied when reading string values.

fn max_substitution_depth(&self) -> usize

Returns the maximum recursion depth allowed when resolving nested ${...} references.

fn description(&self) -> Option<&str>

Returns the optional human-readable description attached to this configuration (the whole document; prefix views expose the same value as the underlying crate::Config).

fn get_property(&self, name: &str) -> Option<&Property>

Returns a reference to the raw Property for name, if present.

fn len(&self) -> usize

Number of configuration entries visible to this reader (all keys for crate::Config; relative keys only for a ConfigPrefixView).

fn is_empty(&self) -> bool

Returns true when Self::len is zero.

fn keys(&self) -> Vec<String>

All keys visible to this reader (relative keys for a prefix view).

fn contains(&self, name: &str) -> bool

Returns whether a property exists for the given key.

fn get<T>(&self, name: &str) -> ConfigResult<T>

where MultiValues: MultiValuesFirstGetter<T>,

Reads the first stored value for name and converts it to T.

fn get_list<T>(&self, name: &str) -> ConfigResult<Vec<T>>

where MultiValues: MultiValuesGetter<T>,

Reads all stored values for name and converts each element to T.

fn get_optional<T>(&self, name: &str) -> ConfigResult<Option<T>>

where MultiValues: MultiValuesFirstGetter<T>,

Gets an optional value with the same semantics as crate::Config::get_optional.

fn get_optional_list<T>(&self, name: &str) -> ConfigResult<Option<Vec<T>>>

where MultiValues: MultiValuesGetter<T>,

Gets an optional list with the same semantics as crate::Config::get_optional_list.

fn contains_prefix(&self, prefix: &str) -> bool

Returns whether any key visible to this reader starts with prefix.

fn iter_prefix<'b>( &'b self, prefix: &'b str, ) -> Box<dyn Iterator<Item = (&'b str, &'b Property)> + 'b>

Iterates (key, property) pairs for keys that start with prefix.

fn iter<'b>(&'b self) -> Box<dyn Iterator<Item = (&'b str, &'b Property)> + 'b>

Iterates all (key, property) pairs visible to this reader (same scope as Self::keys).

fn is_null(&self, name: &str) -> bool

Returns true if the key exists and the property has no values (same as crate::Config::is_null).

fn subconfig(&self, prefix: &str, strip_prefix: bool) -> ConfigResult<Config>

Extracts a subtree as a new Config (same semantics as crate::Config::subconfig; on a prefix view, prefix is relative to the view).

fn deserialize<T>(&self, prefix: &str) -> ConfigResult<T>

where T: DeserializeOwned,

Deserializes the subtree at prefix with serde (same as crate::Config::deserialize; on a prefix view, prefix is relative).

fn prefix_view(&self, prefix: &str) -> ConfigPrefixView<'a>

Creates a read-only prefix view; relative keys resolve under prefix.

fn resolve_key(&self, name: &str) -> String

Resolves name into the canonical key path against the root crate::Config.

fn get_or<T>(&self, name: &str, default: T) -> T

where MultiValues: MultiValuesFirstGetter<T>,

Gets a value or default if the key is missing or conversion fails (same as crate::Config::get_or).

fn get_string(&self, name: &str) -> ConfigResult<String>

Gets a string value, applying variable substitution when enabled.

fn get_string_or(&self, name: &str, default: &str) -> String

Gets a string value with substitution, or default if lookup or substitution fails.

fn get_string_list(&self, name: &str) -> ConfigResult<Vec<String>>

Gets all string values for name, applying substitution to each element when enabled.

fn get_string_list_or(&self, name: &str, default: &[&str]) -> Vec<String>

Gets a string list with substitution, or copies default if lookup fails.

fn get_optional_string(&self, name: &str) -> ConfigResult<Option<String>>

Gets an optional string with the same three-way semantics as crate::Config::get_optional_string.

fn get_optional_string_list( &self, name: &str, ) -> ConfigResult<Option<Vec<String>>>

Gets an optional string list with per-element substitution when enabled.

impl<'a> Debug for ConfigPrefixView<'a>

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

Formats the value using the given formatter.