Function normalize_attribute_value 

pub fn normalize_attribute_value<'input, 'entity, C, E, F>(
    value: &'input str,
    depth: usize,
    is_normalization_char: C,
    normalize_eol_step: E,
    resolve_entity: F,
) -> Result<Cow<'input, str>, EscapeError>
where
    C: Fn(&u8) -> bool,
    E: Fn(&mut String, &str, usize, char) -> usize,
    F: FnMut(&str) -> Option<&'entity str>,

Returns the attribute value normalized as per the XML specification, using a custom entity resolver.

Do not use this method with HTML attributes.

Escape sequences such as > are replaced with their unescaped equivalents, and the characters \t, \r, \n are replaced with a space. This allocates unless the raw attribute value does not require normalization.

Parameters

• value: the unnormalized attribute value;
• depth: maximum number of nested entities that can be expanded before EscapeError::TooManyNestedEntities is returned;
• is_normalization_char: predicate reporting whether a byte begins a character requiring normalization (UTF-8 encoding assumed);
• normalize_eol_step: a function performing EOL normalization of a character;
• resolve_entity: a function to resolve named entities.