Crate mrrc

Expand description

§MRRC: MARC Rust Crate

A Rust library for reading, writing, and manipulating MARC bibliographic records, with Python bindings.

Note: This project was developed using agentic coding tools (amp and Claude) and uses beads for agentic issue tracking. The package has not yet had extensive practical testing by humans and should be considered experimental.

§Features

Reads and writes ISO 2709 (MARC21) binary format
Python bindings with pymarc-compatible API (minor differences documented)
Multiple serialization formats: JSON, MARCXML, MARCJSON, CSV, Dublin Core, MODS, BIBFRAME
MARC-8 and UTF-8 character encoding support
Benchmarked at ~4x pymarc throughput in Python, ~1M records/sec in Rust

§Installation

Python (3.10+):

pip install mrrc
# or with uv:
uv add mrrc

Rust:

cargo add mrrc

§Example

Python:

from mrrc import MARCReader

# Pass filename directly for best performance (releases GIL)
for record in MARCReader("records.mrc"):
    print(record.title())

File paths use pure Rust I/O, releasing Python’s GIL for multi-threaded workloads. See the threading guide for details.

Rust:

use mrrc::MarcReader;
use std::fs::File;

let file = File::open("records.mrc")?;
let mut reader = MarcReader::new(file);
while let Some(record) = reader.read_record()? {
    if let Some(title) = record.title() {
        println!("{}", title);
    }
}

§Documentation

§Format Support

Format	Read	Write
ISO 2709	Yes	Yes
JSON	Yes	Yes
MARCJSON	Yes	Yes
MARCXML	Yes	Yes
CSV	-	Yes
Dublin Core	-	Yes
MODS	Yes	Yes
BIBFRAME	Yes	Yes

Full format reference

§Platforms

Pre-built Python wheels are available for:

Platform	Architectures
Linux	`x86_64`, `aarch64`, `i686`
macOS	`x86_64` (Intel), `arm64` (Apple Silicon)
Windows	x64

§Status

Experimental. The Python API aims for pymarc compatibility but has some differences; see the migration guide. Rust APIs may change between minor versions.

§Roadmap

Version 0.7.0 is suitable for testing but remains experimental. Before a 1.0 release, we plan to complete:

Real-world data testing — Validate against large-scale MARC datasets from LOC, Internet Archive, and other sources to discover edge cases
Code review — Thorough review of the codebase, particularly the Rust core and PyO3 bindings
Performance analysis — Profile with production workloads, optimize bottlenecks, and update benchmark documentation

§License

MIT

§Links

§MRRC: MARC Rust Crate

A high-performance Rust library for reading, writing, and manipulating MARC bibliographic records in the ISO 2709 binary format.

§Quick Start

§Reading MARC Records

use mrrc::MarcReader;
use std::fs::File;

let file = File::open("records.mrc")?;
let mut reader = MarcReader::new(file);

while let Some(record) = reader.read_record()? {
    if let Some(title) = record.title() {
        println!("Title: {}", title);
    }
}

§Creating and Writing MARC Records

use mrrc::{MarcWriter, Record, Field, Leader};

let mut record = Record::new(Leader::default());
record.add_control_field("001".to_string(), "12345".to_string());

let mut field = Field::new("245".to_string(), '1', '0');
field.add_subfield('a', "Test Title".to_string());
record.add_field(field);

let mut buffer = Vec::new();
{
    let mut writer = MarcWriter::new(&mut buffer);
    writer.write_record(&record)?;
}

§Using Helper Methods

use mrrc::{Record, Leader, Field};

let mut record = Record::new(Leader::default());

let mut field_245 = Field::new("245".to_string(), '1', '0');
field_245.add_subfield('a', "The Great Gatsby".to_string());
field_245.add_subfield('c', "F. Scott Fitzgerald".to_string());
record.add_field(field_245);

// Use convenience methods
assert_eq!(record.title(), Some("The Great Gatsby"));
assert_eq!(record.is_book(), true);

§Modules

record — Core MARC record structures (Record, Field, Subfield)
reader — Reading MARC records from binary data streams
writer — Writing MARC records to binary format
formats — Format traits and ISO 2709 support
bibframe — BIBFRAME linked data conversion
boundary_scanner — Record boundary detection for parallel processing
leader — MARC record leader (24-byte header)
json — JSON serialization/deserialization
marcjson — MARCJSON format (standard JSON-LD format for MARC)
marcxml — MARCXML serialization/deserialization
csv — CSV (Comma-Separated Values) export format
dublin_core — Dublin Core metadata serialization
mods — MODS (Metadata Object Description Schema) bidirectional conversion
encoding — Character encoding support (MARC-8 and UTF-8)
error — Error types and result type

§Format Support

ISO 2709 Binary Format — The standard MARC interchange format
BIBFRAME — LOC linked data format for bibliographic description
JSON — Generic JSON representation of records
MARCJSON — Standard JSON-LD format for MARC records
MARCXML — Standard LOC MARCXML with proper attributes and namespace
CSV — Tabular export format for spreadsheet applications
Dublin Core — Simplified metadata schema for discovery
MODS — Detailed metadata description schema for libraries
Character Encodings — MARC-8 and UTF-8 with automatic detection

Re-exports§

pub use authority_queries::AuthorityQueries;
pub use authority_reader::AuthorityMarcReader;
pub use authority_record::AuthorityRecord;
pub use authority_record::AuthorityRecordBuilder;
pub use authority_record::HeadingType;
pub use authority_record::KindOfRecord;
pub use authority_record::LevelOfEstablishment;
pub use authority_writer::AuthorityMarcWriter;
pub use bibliographic_helpers::IsbnValidator;
pub use bibliographic_helpers::PublicationInfo;
pub use encoding_validation::EncodingAnalysis;
pub use encoding_validation::EncodingValidator;
pub use error::MarcError;
pub use error::Result;
pub use field_linkage::LinkageInfo;
pub use field_query::FieldQuery;
pub use field_query::SubfieldPatternQuery;
pub use field_query::SubfieldValueQuery;
pub use field_query::TagRangeQuery;
pub use field_query_helpers::FieldQueryHelpers;
pub use format_queries::AuthoritySpecificQueries;
pub use format_queries::BibliographicQueries;
pub use format_queries::HoldingsSpecificQueries;
pub use holdings_reader::HoldingsMarcReader;
pub use holdings_record::AcquisitionStatus;
pub use holdings_record::Completeness;
pub use holdings_record::HoldingsRecord;
pub use holdings_record::HoldingsRecordBuilder;
pub use holdings_record::HoldingsType;
pub use holdings_record::MethodOfAcquisition;
pub use holdings_writer::HoldingsMarcWriter;
pub use leader::Leader;
pub use marc_record::MarcRecord;
pub use producer_consumer_pipeline::PipelineConfig;
pub use producer_consumer_pipeline::PipelineError;
pub use producer_consumer_pipeline::ProducerConsumerPipeline;
pub use reader::MarcReader;
pub use record::Field;
pub use record::FieldBuilder;
pub use record::Record;
pub use record::RecordBuilder;
pub use record::Subfield;
pub use record_builder_generic::GenericRecordBuilder;
pub use record_helpers::RecordHelpers;
pub use record_validation::RecordStructureValidator;
pub use recovery::RecoveryContext;
pub use recovery::RecoveryMode;
pub use validation::IndicatorValidator;
pub use writer::MarcWriter;

Modules§

authority_queries: Authority control helper methods and queries.
authority_reader: Reading MARC Authority records from binary streams.
authority_record: MARC Authority Record structures and utilities.
authority_writer: Writing MARC Authority records to binary format.
bibframe: BIBFRAME conversion for MARC records.
bibliographic_helpers: Bibliographic helper utilities for MARC records.
boundary_scanner: Record boundary detection using 0x1D delimiters for parallel processing.
csv: CSV serialization of MARC records.
dublin_core: Dublin Core serialization of MARC records.
encoding: Character encoding support for MARC records.
encoding_validation: Encoding detection and validation for MARC records.
error: Error types for MARC operations.
field_collection: Field collection traits for managing MARC record field collections.
field_linkage: Field linkage support for MARC 880 (Alternate Graphical Representation) fields.
field_query: Advanced field query patterns for MARC records.
field_query_helpers: Convenience helper methods for advanced field queries.
format_queries: Format-specific query traits for different MARC record types.
formats: Multi-format support with unified Reader/Writer traits.
holdings_reader: Reading MARC Holdings records from binary streams.
holdings_record: MARC Holdings Record structures and utilities.
holdings_writer: Writing MARC Holdings records to binary format.
json: JSON serialization and deserialization of MARC records.
leader: MARC record leader parsing and manipulation.
macros: Macros for code generation in MARC record types.
marc8_tables: MARC-8 character set tables and mappings.
marc_record: Core trait for all MARC record types.
marcjson: MARCJSON serialization and deserialization of MARC records.
marcxml: MARCXML serialization and deserialization of MARC records.
mods: MODS (Metadata Object Description Schema) conversion for MARC records.
producer_consumer_pipeline: Producer-Consumer Pipeline with Backpressure
rayon_parser_pool: Parallel MARC record parsing using Rayon.
reader: Reading MARC records from binary streams.
record: Core MARC record structures (Record, Field, Subfield) MARC bibliographic record structures and operations.
record_builder_generic: Generic builder for all MARC record types.
record_helpers: Helper methods for accessing common bibliographic fields.
record_validation: Validation of MARC record structure and integrity.
recovery: Recovery strategies for malformed and truncated MARC records.
validation: Indicator and field validation for MARC records.
writer: Writing MARC records to binary format.

Macros§

define_field_accessors: Macro to generate add/get accessor methods for a field collection.
filtered_field_accessor: Macro to generate filtered accessor methods for a field collection by tag.

Crate mrrc

Crate mrrc Copy item path

§MRRC: MARC Rust Crate

§Features

§Installation

§Example

§Documentation

§Format Support

§Platforms

§Status

§Roadmap

§License

§Links

§MRRC: MARC Rust Crate

§Quick Start

§Reading MARC Records

§Creating and Writing MARC Records

§Using Helper Methods

§Modules

§Format Support

Re-exports§

Modules§

Macros§

Crate mrrc