Struct DetectionOptions 

pub struct DetectionOptions {
    pub steps: usize,
    pub chunk_size: usize,
    pub threshold: f64,
    pub cp_isolation: Vec<String>,
    pub cp_exclusion: Vec<String>,
    pub preemptive_behaviour: bool,
    pub explain: bool,
    pub language_threshold: f64,
    pub enable_fallback: bool,
}

Tuning knobs of from_bytes_with and detect.

The Default values match the Python package’s from_bytes. Override only the fields you need with struct update syntax:

use charset_norm::DetectionOptions;

let options = DetectionOptions {
    // Never consider these code pages, whatever the payload looks like.
    cp_exclusion: vec!["utf_7".into(), "hz".into()],
    // Look at more of the payload.
    steps: 10,
    ..DetectionOptions::default()
};
assert_eq!(options.chunk_size, 512);

Fields

steps: usize

Number of chunks sampled from the payload. Default: 5.

Chunks are spread evenly over the payload. When the payload is not longer than steps * chunk_size bytes, it is analysed whole, as a single chunk.

chunk_size: usize

Size of each sampled chunk, in bytes. Default: 512.

Shrunk automatically when the payload is too short to hold steps chunks of this size.

threshold: f64

Maximum acceptable mean chaos (see mess::mess_ratio) for a candidate encoding. Default: 0.2.

Lower values reject more candidates; raise it to accept noisier text.

cp_isolation: Vec<String>

When not empty, only these encodings are tried. Default: empty.

Names may be any alias ("windows-1252", "UTF-8", …).

cp_exclusion: Vec<String>

Encodings never tried, by any alias. Default: empty.

preemptive_behaviour: bool

Favour an encoding declared inside the payload, such as <meta charset="..."> in HTML or a # coding: ... comment in Python sources. Default: true.

Only the first 8 KiB are searched. A declared encoding is tried right after any BOM-announced one, and detection stops there when it decodes the payload without any chaos.

explain: bool

Log the chaos breakdown of every sampled chunk at Level::Trace. Default: false.

Only takes effect when cp_isolation names one or two encodings, to keep the output readable.

language_threshold: f64

Minimum coherence (in [0, 1]) for a language to be reported. Default: 0.1.

enable_fallback: bool

Fall back on ASCII, UTF-8 or a declared encoding when every candidate is rejected but one of those still decodes the payload. Default: true.

Without the fallback, text that is merely noisy can come back as no match at all (see is_binary).

Trait Implementations

impl Clone for DetectionOptions

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DetectionOptions

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

Formats the value using the given formatter.

impl Default for DetectionOptions

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for DetectionOptions

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for DetectionOptions