Enum BytesMode 

pub enum BytesMode {
    Unicode,
    Ascii,
    UnicodeBytes,
}

Controls how the regex engine handles input encoding.

This enum represents the three valid combinations of the utf8 and unicode flags in the underlying regex engine. Each variant has different trade-offs between input flexibility and character class semantics.

The default is BytesMode::Unicode.

Variants

BytesMode::Unicode (default)

• Input is expected to be valid UTF-8
• . matches any Unicode scalar value (except \n unless dot_matches_new_line is set)
• \w, \d, \s match Unicode characters
• Unicode properties like \p{Letter} are available
• Word boundaries (\b) are Unicode-aware

BytesMode::Ascii

• Input can be arbitrary bytes (no UTF-8 requirement)
• . matches any single byte (except \n unless dot_matches_new_line is set)
• \w matches [a-zA-Z0-9_] only (ASCII)
• \d matches [0-9] only (ASCII)
• \s matches ASCII whitespace only
• Unicode properties are not available
• Word boundaries (\b) use ASCII-only word characters

Use this mode when matching raw binary data or filenames that may contain non-UTF-8 bytes and you don’t need Unicode character classes.

BytesMode::UnicodeBytes

• Input can be arbitrary bytes (no UTF-8 requirement)
• . matches Unicode scalar values (sequences of valid UTF-8 bytes)
• \w, \d, \s match Unicode characters
• Unicode properties like \p{Letter} are available

Use this mode when the input may contain non-UTF-8 bytes but you still want Unicode-aware character classes. Note that . will not match individual non-UTF-8 bytes — it only matches valid UTF-8 codepoint sequences.

Variants

Unicode

Unicode mode: input must be valid UTF-8, full Unicode support. (utf8=true, unicode=true)

Ascii

ASCII bytes mode: . matches any byte, character classes are ASCII-only. (utf8=false, unicode=false)

UnicodeBytes

Unicode-aware bytes mode: input can be non-UTF-8, character classes remain Unicode-aware. . matches Unicode scalar values only. (utf8=false, unicode=true)

Trait Implementations

impl Clone for BytesMode

fn clone(&self) -> BytesMode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for BytesMode

impl Debug for BytesMode

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

Formats the value using the given formatter.

impl Default for BytesMode

fn default() -> BytesMode

Returns the “default value” for a type.

impl Eq for BytesMode

impl PartialEq for BytesMode

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for BytesMode