Struct RuleMatch 

#[non_exhaustive]
pub struct RuleMatch {
    pub message: String,
    pub offset: usize,
    pub level: u32,
    pub value: Value,
    pub type_kind: TypeKind,
    pub confidence: f64,
}

Result of evaluating a magic rule

Contains information extracted from a successful rule match, including the matched value, position, and confidence score.

This type derives Serialize so callers can convert evaluation results to JSON, but intentionally does NOT derive Deserialize: a reconstructed RuleMatch would lack the buffer context it was produced against, so deserialization is not a meaningful operation. The output-side conversion layer (output::MatchResult / output::json::JsonMatchResult) is the documented JSON contract.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

message: String

The message associated with the matching rule

offset: usize

The offset where the match occurred

level: u32

The rule level (depth in hierarchy)

value: Value

The matched value

type_kind: TypeKind

The type used to read the matched value

Carries the source TypeKind so downstream consumers (e.g., output formatting) can determine the on-disk width of the matched value.

#[serde(skip)] keeps the parser AST out of JSON output produced by serializing EvaluationResult directly via serde_json::to_string(&result). The documented JSON contract is JsonMatchResult in src/output/json.rs, which omits this field. Origin findings 1B-H2 / 2A-M1 (CWE-200 information exposure). Rust-side consumers continue to access type_kind via field access for runtime needs (format_magic_message width-masking, bit_width() derivation).

confidence: f64

Confidence score (0.0 to 1.0)

Calculated based on match depth in the rule hierarchy. Deeper matches indicate more specific file type identification and thus higher confidence.

Implementations

impl RuleMatch

pub fn new( message: String, offset: usize, level: u32, value: Value, type_kind: TypeKind, confidence: f64, ) -> Self

Construct a new RuleMatch.

confidence is typically derived from level via RuleMatch::calculate_confidence; pass it explicitly here so callers can supply an alternative score when needed (e.g. when post-processing a series of matches).

pub fn calculate_confidence(level: u32) -> f64

Calculate confidence score based on rule depth

Formula: min(1.0, 0.3 + (level * 0.2))

• Level 0 (root): 0.3
• Level 1: 0.5
• Level 2: 0.7
• Level 3: 0.9
• Level 4+: 1.0 (capped)

Examples

use libmagic_rs::evaluator::RuleMatch;

assert!((RuleMatch::calculate_confidence(0) - 0.3).abs() < 0.001);
assert!((RuleMatch::calculate_confidence(3) - 0.9).abs() < 0.001);
assert!((RuleMatch::calculate_confidence(10) - 1.0).abs() < 0.001);

Trait Implementations

impl Clone for RuleMatch

fn clone(&self) -> RuleMatch

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RuleMatch

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

Formats the value using the given formatter.

impl PartialEq for RuleMatch

fn eq(&self, other: &RuleMatch) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for RuleMatch

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for RuleMatch