mrrc 0.7.6

A Rust library for reading, writing, and manipulating MARC bibliographic records in ISO 2709 binary format
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

//! MARC-8 Encoding Example
//!
//! This example demonstrates:
//! - Detecting MARC-8 vs UTF-8 encoding in MARC records
//! - Understanding MARC-8 character set switching with escape sequences
//! - Working with multilingual text (Hebrew, Arabic, Greek, Cyrillic)
//! - Proper handling of combining characters and diacritics

use mrrc::encoding::MarcEncoding;

fn main() {
    println!("=== MARC-8 Encoding Support ===\n");

    // Example 1: Detecting encoding from MARC leader
    detect_encoding_example();

    // Example 2: Understanding character sets in MARC-8
    character_sets_example();

    // Example 3: Handling multilingual records
    multilingual_example();
}

/// Demonstrates detecting the character encoding from a MARC record's leader.
fn detect_encoding_example() {
    println!("1. Detecting Character Encoding from Leader");
    println!("   A MARC leader's character position 9 indicates the encoding:\n");

    // Space character = MARC-8 (legacy encoding)
    let leader_char_marc8 = ' ';
    match MarcEncoding::from_leader_char(leader_char_marc8) {
        Ok(encoding) => {
            println!("   Leader position 9 = '{leader_char_marc8}'");
            println!("   Encoding: {encoding:?}\n");
        },
        Err(e) => eprintln!("   Error: {e}\n"),
    }

    // 'a' = UTF-8 (modern encoding)
    let leader_char_utf8 = 'a';
    match MarcEncoding::from_leader_char(leader_char_utf8) {
        Ok(encoding) => {
            println!("   Leader position 9 = '{leader_char_utf8}'");
            println!("   Encoding: {encoding:?}\n");
        },
        Err(e) => eprintln!("   Error: {e}\n"),
    }
}

/// Explains the character sets available in MARC-8 and their escape sequences.
fn character_sets_example() {
    println!("2. MARC-8 Character Set Overview");
    println!("   MARC-8 uses ISO 2022 escape sequences to switch between character sets.\n");

    let character_sets = vec![
        (
            "Basic Latin (ASCII)",
            "Default (G0)",
            "ESC ( B",
            "0x20-0x7E",
        ),
        (
            "ANSEL Extended Latin",
            "Default (G1)",
            "ESC ) E",
            "0xA0-0xFE (diacritics)",
        ),
        ("Basic Hebrew", "0x32", "ESC ) 2", "0xA1-0xBB (22 letters)"),
        ("Basic Arabic", "0x33", "ESC ) 3", "0xA1-0xBA (20+ letters)"),
        (
            "Extended Arabic",
            "0x34",
            "ESC ) 4",
            "Extended Arabic characters",
        ),
        (
            "Basic Cyrillic",
            "0x4E",
            "ESC ( N",
            "Russian/Slavic characters",
        ),
        ("Basic Greek", "0x53", "ESC ( S", "Greek alphabet"),
        ("Greek Symbols", "0x67", "ESC g", "α, β, γ (deprecated)"),
        ("Subscripts", "0x62", "ESC b", "₀-₉, ₊, ₋, ₍, ₎ (14 chars)"),
        (
            "Superscripts",
            "0x70",
            "ESC p",
            "⁰-⁹, ⁺, ⁻, ⁽, ⁾ (14 chars)",
        ),
        (
            "East Asian (EACC)",
            "0x31",
            "ESC $ 1",
            "Chinese, Japanese, Korean",
        ),
    ];

    println!("   Character Set          | Final Char | Escape Sequence | Examples");
    println!("   {}", "-".repeat(75));

    for (name, final_char, escape, examples) in character_sets {
        println!("   {name:<22} | {final_char:<10} | {escape:<15} | {examples}");
    }
    println!();
}

/// Demonstrates handling multilingual MARC records with different scripts.
fn multilingual_example() {
    println!("3. Working with Multilingual Records");
    println!("   MARC-8 stores data in LOGICAL order (not visual), so:");
    println!("   - RTL scripts (Arabic, Hebrew) are stored left-to-right logically");
    println!("   - Mixed LTR/RTL requires proper escape sequence handling");
    println!("   - Combining marks (diacritics) precede their base character\n");

    println!("   Example: Mixed English + Hebrew record");
    println!("   ────────────────────────────────────");
    println!("   Display:  Hello שלום !");
    println!("   Logical:  H e l l o [ESC)2] ש ל ו ם [ESC)E] !");
    println!("            ↑ ASCII (default) ↑ Hebrew set ↑ Back to ANSEL\n");

    println!("   Key points for MARC-8:");
    println!("   • Escape sequences can occur anywhere (within words, fields, subfields)");
    println!("   • Combining characters appear BEFORE the base character");
    println!("   • Must reset to ASCII (ESC s) or ANSEL (ESC ) E) before field terminator");
    println!("   • Unicode normalization (NFC) is applied to normalize combining chars\n");

    println!("   Example: Hebrew with diacritics");
    println!("   ─────────────────────────────");
    println!("   Data: [combining-mark] [hebrew-letter]");
    println!("   Display: hebrew-letter with diacritic applied\n");
}