Rust Requires Chilkat v11.7.0+

Expand Ligatures and Normalize Unicode in Extracted PDF Text

See more PDF Text Extraction Examples

Demonstrates the "expandLigatures" and "normalize" clean-up options. Typeset PDFs use single glyphs for "fi" and "fl"; by default they are expanded to their letters. Unicode normalization is NFC by default; NFKC also folds compatibility characters such as circled digits, the trademark sign and vulgar fractions into plain characters, and "none" leaves the text as the PDF has it. Rust

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// The PDF used in this example is available at ligatures.pdf

let pdf = chilkat::Pdf::new();
if pdf.load_file("qa_data/pdf/ligatures.pdf").is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

let json = chilkat::JsonObject::new();
let json_out = chilkat::JsonObject::new();

// The first line is set with the fi and fl ligature glyphs; the second has circled digits,
// a trademark sign and a vulgar fraction.
if pdf.extract_text("text", &json, &json_out).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("---- default (expandLigatures: true, normalize: NFC) ----");
println!("{}", json_out.string_of("text").unwrap_or_default());

// Keep the ligature characters as they are in the PDF.
let _ = json.update_bool("expandLigatures", false);
let _ = json.update_string("normalize", "none");
if pdf.extract_text("text", &json, &json_out).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("---- expandLigatures: false, normalize: none ----");
println!("{}", json_out.string_of("text").unwrap_or_default());

// NFKC folds the compatibility characters too (and expands ligatures on its own).
let _ = json.update_string("normalize", "NFKC");
if pdf.extract_text("text", &json, &json_out).is_err() {
    println!("{}", pdf.last_error_text());
    return;
}

println!("---- normalize: NFKC ----");
println!("{}", json_out.string_of("text").unwrap_or_default());

// Sample output (shown here in ASCII: (fi) and (fl) stand for the single ligature characters, (1) and (2) for the circled digits,
// (TM) for the trademark sign and 1/2 for the vulgar fraction; the NFKC output has plain "1", "2", "TM" and "1", fraction slash, "2"):

// ---- default (expandLigatures: true, normalize: NFC) ----
// Typeset Text
// 
// The final flight of the season was officially confirmed on the fifth. Rooms (1) and (2) are reserved; the Harbor Cafe(TM) serves 1/2 portions.
// ---- expandLigatures: false, normalize: none ----
// Typeset Text
// 
// The (fi)nal (fl)ight of the season was of(fi)cially con(fi)rmed on the (fi)fth. Rooms (1) and (2) are reserved; the Harbor Cafe(TM) serves 1/2 portions.
// ---- normalize: NFKC ----
// Typeset Text
// 
// The final flight of the season was officially confirmed on the fifth. Rooms 1 and 2 are reserved; the Harbor CafeTM serves 1/2 portions.