Struct SubfieldPatternQuery 

#[non_exhaustive]
pub struct SubfieldPatternQuery {
    pub tag: String,
    pub subfield_code: char,
    pub negate: bool,
    /* private fields */
}

Query for fields with subfield values matching a regex pattern.

This enables finding fields where a specific subfield’s value matches a regular expression pattern.

Examples

// Find all ISBNs that start with 978
let query = SubfieldPatternQuery::new("020", 'a', "^978-.*");
for field in record.fields_matching_pattern(&query) {
    println!("ISBN: {:?}", field);
}

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.

tag: String

Tag to match

subfield_code: char

Subfield code to match

negate: bool

If true, match fields where the subfield does NOT match the pattern

Implementations

impl SubfieldPatternQuery

pub fn new( tag: impl Into<String>, subfield_code: char, pattern: &str, ) -> Result<Self, Error>

Create a new subfield pattern query.

Arguments

• tag - The field tag to search in
• subfield_code - The subfield code to match against
• pattern - A regex pattern string

Returns

Ok(SubfieldPatternQuery) if the pattern is valid regex, or Err if invalid.

Errors

Returns a regex::Error if the pattern is not a valid regular expression.

Examples

let query = SubfieldPatternQuery::new("650", 'a', r"^[A-Z]")?;

pub fn negated( tag: impl Into<String>, subfield_code: char, pattern: &str, ) -> Result<Self, Error>

Create a negated subfield pattern query.

Matches fields where the subfield exists but does NOT match the pattern.

Errors

Returns a regex::Error if the pattern is not a valid regular expression.

pub fn matches(&self, field: &Field) -> bool

Check if a field matches this pattern query.

Trait Implementations

impl Clone for SubfieldPatternQuery

fn clone(&self) -> SubfieldPatternQuery

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SubfieldPatternQuery

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

Formats the value using the given formatter.