val_latex 0.1.1

LaTeX math typesetting in pure Dart: a TeX parser, macros, TeX layout with line breaking and right-to-left math, OpenType math fonts, and speech output.

example/example.dart

// Parses LaTeX math, lays it out, and reads the result.
//
//   dart run example/example.dart
import 'package:val_latex/val_latex.dart';

void main() {
  // Parse: never throws; problems become diagnostics.
  final result = parseLatex(r'x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}');
  print('Diagnostics: ${result.diagnostics.length}');

  // Lay out with TeX's rules and the bundled Latin Modern Math font.
  // Sizes are in em: multiply by the font size for pixels.
  final layout = layoutFormula(result);
  print(
    'Size: ${layout.width.toStringAsFixed(2)} × '
    '${(layout.height + layout.depth).toStringAsFixed(2)} em',
  );
  print('Display items to draw: ${layout.items.length}');

  // Break a long formula to a width, in display style.
  final wrapped = renderLatex(
    r'\sum_{k=1}^{n} k^2 = \frac{n(n+1)(2n+1)}{6} = 1 + 4 + 9 + \cdots + n^2',
    layoutOptions: const LayoutOptions(displayMode: true, maxWidth: 10),
  );
  print('Lines at 10 em: ${wrapped.lineCount}');

  // Unfinished input, as an LLM streams it, renders as far as it goes.
  final partial = parseLatex(r'\frac{a}{');
  print('Incomplete: ${partial.incomplete}');

  // Spoken form, for screen readers.
  print('Speech: ${toSpeech(result)}');

  // Normalised LaTeX back.
  print('LaTeX: ${toLatex(result)}');
}