Struct MD053LinkImageReferenceDefinitions 

pub struct MD053LinkImageReferenceDefinitions { /* private fields */ }

Rule MD053: Link and image reference definitions should be used

See docs/md053.md for full documentation, configuration, and examples.

This rule is triggered when a link or image reference definition is declared but not used anywhere in the document. Unused reference definitions can create confusion and clutter.

Supported Reference Formats

This rule handles the following reference formats:

• Full reference links/images: [text][reference] or ![text][reference]
• Collapsed reference links/images: [text][] or ![text][]
• Shortcut reference links: [reference] (must be defined elsewhere)
• Reference definitions: [reference]: URL "Optional Title"
• Multi-line reference definitions:

  [reference]: URL
     "Optional title continued on next line"

Configuration Options

The rule supports the following configuration options:

MD053:
  ignored_definitions: []  # List of reference definitions to ignore (never report as unused)

Performance Optimizations

This rule implements various performance optimizations for handling large documents:

1. Caching: The rule caches parsed definitions and references based on content hashing
2. Efficient Reference Matching: Uses HashMaps for O(1) lookups of definitions
3. Smart Code Block Handling: Efficiently skips references inside code blocks/spans
4. Lazy Evaluation: Only processes necessary portions of the document

Edge Cases Handled

• Case insensitivity: References are matched case-insensitively
• Escaped characters: Properly processes escaped characters in references
• Unicode support: Handles non-ASCII characters in references and URLs
• Code blocks: Ignores references inside code blocks and spans
• Special characters: Properly handles references with special characters

Fix Behavior

This rule does not provide automatic fixes. Unused references must be manually reviewed and removed, as they may be intentionally kept for future use or as templates.

Implementations

impl MD053LinkImageReferenceDefinitions

pub fn new() -> Self

Create a new instance of the MD053 rule

pub fn from_config_struct(config: MD053Config) -> Self

Create a new instance with the given configuration

Trait Implementations

impl Clone for MD053LinkImageReferenceDefinitions

fn clone(&self) -> MD053LinkImageReferenceDefinitions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Default for MD053LinkImageReferenceDefinitions

fn default() -> Self

Returns the “default value” for a type.

impl Rule for MD053LinkImageReferenceDefinitions

fn check(&self, ctx: &LintContext<'_>) -> LintResult

Check the content for unused and duplicate link/image reference definitions.

This implementation uses caching for improved performance on large documents.

fn fix(&self, ctx: &LintContext<'_>) -> Result<String, LintError>

MD053 does not provide automatic fixes

fn should_skip(&self, ctx: &LintContext<'_>) -> bool

Check if this rule should be skipped for performance

fn name(&self) -> &'static str

fn description(&self) -> &'static str

fn category(&self) -> RuleCategory

Get the category of this rule for selective processing

fn fix_capability(&self) -> FixCapability

Declares the fix capability of this rule

fn as_any(&self) -> &dyn Any

fn default_config_section(&self) -> Option<(String, Value)>

Returns the rule name and default config table if the rule has config. If a rule implements this, it MUST be defined on the impl Rule for ... block, not just the inherent impl.

fn config_schema(&self) -> Option<(String, Value)>

Returns the rule name and every config key the rule accepts, for validation.

fn from_config(config: &Config) -> Box<dyn Rule>

where Self: Sized,

Factory: create a rule from config (if present), or use defaults.

fn skippable_by_category(&self) -> bool

Whether the content-category prefilter may skip this rule.

fn config_aliases(&self) -> Option<HashMap<String, String>>

Returns config key aliases for this rule This allows rules to accept alternative config key names for backwards compatibility

fn polymorphic_config_keys(&self) -> &'static [&'static str]

Returns the list of config keys whose deserializer accepts more than one TOML type (e.g. either a scalar or a list). The schema is built from a serialized default that can only encode one variant, so the validator would reject the alternative form. The registry replaces the schema entry for each listed key with a polymorphic sentinel so type checking is skipped while the key name is still validated. The registry rewrites Rule::config_schema, so default_config_section() keeps returning the clean user-facing default.

fn cross_file_scope(&self) -> CrossFileScope

Declares cross-file analysis requirements for this rule

fn contribute_to_index( &self, _ctx: &LintContext<'_>, _file_index: &mut FileIndex, )

Contribute data to the workspace index during linting

fn cross_file_check( &self, _file_path: &Path, _file_index: &FileIndex, _workspace_index: &WorkspaceIndex, ) -> LintResult

Perform cross-file validation after all files have been linted

fn observes_suppressions(&self) -> bool

Whether this rule reports on the inline comments that suppressed warnings

fn check_suppressions( &self, _ctx: &LintContext<'_>, _report: &SuppressionReport, ) -> LintResult

Report on a document’s inline disable comments