hyphenatorx 1.1.3

Implementation of an hyphenation algorithm, based on TeX definitions.

Hyphenator

Implementation of an hyphenation algorithm.

The tex patterns used in the algorithm can be found here.

The package seems to work fine for western languages, other languages have to be evaluated.

A live Flutter demo can be found here: https://xerik.github.io/hyphenatorx/.

Installation

flutter pub add hyphenatorx

Usage

Hyphenator instantiates a language specific configuration:

As a Dart object

Without synchronous loading. The data is compiled into your project. All 71 langauge files together have a size of 13.3 MB.

From JSON

With asynchronous loading. The data will be loaded as needed from the local assets folder. This option is less memory intensive.

Languages

Available languages are given by the enum Language.

Cache

Internally, hyphenated as well as non-hyphenated words are cached. Complete texts are not cached, only single words.

Asynchronous Instantiation

Select the appropriate Language.language_XX value.

import 'package:hyphenatorx/hyphenatorx.dart';
import 'package:hyphenatorx/languages/language_en_us.dart';
import 'package:hyphenatorx/languages/languageconfig.dart';

final hyphernator = await Hyphenator.load(
    Language.language_en_us, 
    hyphenateSymbol: '_');

expect(
  hyphenator.hyphenate('subdivision subdivision'), 
  'sub_di_vi_sion sub_di_vi_sion');

expect(
  hyphenator.hyphenateWord('subdivision'),
  'sub_di_vi_sion');

expect(
  hyphenator.hyphenateWordToList('subdivision'),
  ['sub', 'di', 'vi', 'sion']);

Synchronous Instantiation

Instatiate the appropriate Language_XX object.

import 'package:hyphenatorx/hyphenatorx.dart';
import 'package:hyphenatorx/languages/language_en_us.dart';
import 'package:hyphenatorx/languages/languageconfig.dart';

final LanguageConfig config = Language_en_us();

final hyphenator = Hyphenator(
  config,
  hyphenateSymbol: '_',
);

expect(
  hyphenator.hyphenate('subdivision subdivision'), 
  'sub_di_vi_sion sub_di_vi_sion');

expect(
  hyphenator.hyphenateWord('subdivision'),
  'sub_di_vi_sion');

expect(
  hyphenator.hyphenateWordToList('subdivision'),
  ['sub', 'di', 'vi', 'sion']);

Performance

Old machine:

• Instantiation via Dart EN_US file: 30 milliseconds
• Hyphenating text with 258 words: 46 milliseconds

Internal testing whether a character is a letter has the most performance impact.

// FORMER
//
// Results in 54 milliseconds for long text.
//
// final isLetter = (c == c.toLowerCase() && c == c.toUpperCase()) == false;

// BETTER
//
// Results in 46 milliseconds for long text.
// Reduction by 15 %.
//
// final isLetter = textLower[i] != textUpper[i];

// INCREASE, but most precise?
//
// Results in 80 milliseconds for long text.
// Increase by 48 %.
//
// final reLetter = RegExp(r'\p{Letter}', unicode: true);
// final isLetter = reLetter.hasMatch(c);

Generate JSON and Dart files

dart run ./tool/tex2dart.dart

The tool will delete assets and lib/languages before generating new files. It processes tex files located in tool\tex\.

Source

This package is a copy and extension of hyphenator.

Possible performance improvement and general refactoring is TBD.