VisualWidth

This gem handles Unicode East Asian Width:

• http://www.unicode.org/reports/tr11/

Installation

Add this line to your application's Gemfile:

gem 'visual_width'

And then execute:

$ bundle

Or install it yourself as:

$ gem install visual_width

Usage

    # VisualWidth
    require 'visual_width'

    p VisualWidth.measure("こんにちは") # => 10
    p VisualWidth.measure("abcdefghij") # => 10

    p VisualWidth.truncate("恋すてふ 我が名はまだき 立ちにけり 人知れずこそ 思ひそめしか", 20) # => "恋すてふ 我が名は..."

    # VisualWidth::Table
    require 'visual_width/table'

    t = VisualWidth::Table.new(
      format: [VisualWidth::Table::LEFT, VisualWidth::Table::RIGHT, VisualWidth::Table::RIGHT]
    )

    header = ['Student', 'Mid-Terms', 'Finals']
    rows = [
      ['Sam', 94, 93],
      ['Jane', 92, 99],
      ['Average', 93, 96],
    ]
    t.draw(rows, header: header)

Each method can take east_asian: false to tell it is not in an East Asian context, regarding ambiguous characters as half-width.

See Ambiguous Characters in the report.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

See Also

• unicode-display_width has the same feature as VisualWidth.measure() but it extends String class directly and is much slower than VisualWidth.measure()