Class: Unicode::DisplayWidth

Inherits:
Object
  • Object
show all
Defined in:
lib/unicode/display_width.rb,
lib/unicode/display_width/index.rb,
lib/unicode/display_width/constants.rb,
lib/unicode/display_width/emoji_support.rb

Defined Under Namespace

Modules: EmojiSupport

Constant Summary collapse

DEFAULT_AMBIGUOUS = 
1
INITIAL_DEPTH = 
0x10000
ASCII_NON_ZERO_REGEX = 
/[\0\x05\a\b\n-\x0F]/
ASCII_NON_ZERO_STRING = 
"\0\x05\a\b\n-\x0F"
ASCII_BACKSPACE = 
"\b"
AMBIGUOUS_MAP = 
{
  1 => :WIDTH_ONE,
  2 => :WIDTH_TWO,
}
FIRST_AMBIGUOUS = 
{
  WIDTH_ONE: 768,
  WIDTH_TWO: 161,
}
NOT_COMMON_NARROW_REGEX = 
{
 WIDTH_ONE: /[^\u{10}-\u{2FF}]/m,
 WIDTH_TWO: /[^\u{10}-\u{A1}]/m,
}
FIRST_4096 = 
{
  WIDTH_ONE: decompress_index(INDEX[:WIDTH_ONE][0][0], 1),
  WIDTH_TWO: decompress_index(INDEX[:WIDTH_TWO][0][0], 1),
}
EMOJI_SEQUENCES_REGEX_MAPPING = 
{
  rgi: :REGEX_INCLUDE_MQE_UQE,
  rgi_at: :REGEX_INCLUDE_MQE_UQE,
  possible: :REGEX_WELL_FORMED,
}
REGEX_EMOJI_VS16 = 
Regexp.union(
  Regexp.compile(
    Unicode::Emoji::REGEX_TEXT_PRESENTATION.source +
    "(?<![#*0-9])" +
    "\u{FE0F}"
  ),
  Unicode::Emoji::REGEX_EMOJI_KEYCAP
)
REGEX_EMOJI_ALL_SEQUENCES =

ebase = Unicode::Emoji::REGEX_PROP_MODIFIER_BASE.source

Regexp.union(/.[\u{1F3FB}-\u{1F3FF}\u{FE0F}]?(\u{200D}.[\u{1F3FB}-\u{1F3FF}\u{FE0F}]?)+|.[\u{1F3FB}-\u{1F3FF}]/, Unicode::Emoji::REGEX_EMOJI_KEYCAP)
REGEX_EMOJI_ALL_SEQUENCES_AND_VS16 = 
Regexp.union(REGEX_EMOJI_ALL_SEQUENCES, REGEX_EMOJI_VS16)
VERSION = 
"3.2.0"
UNICODE_VERSION = 
"17.0.0"
DATA_DIRECTORY = 
File.expand_path(File.dirname(__FILE__) + "/../../../data/")
INDEX_FILENAME = 
DATA_DIRECTORY + "/display_width.marshal.gz"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ambiguous: DEFAULT_AMBIGUOUS, overwrite: {}, emoji: true) ⇒ DisplayWidth

Returns a new instance of DisplayWidth.



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# File 'lib/unicode/display_width.rb', line 229

def initialize(ambiguous: DEFAULT_AMBIGUOUS, overwrite: {}, emoji: true)
  @ambiguous = ambiguous
  @overwrite = overwrite
  @emoji     = emoji
end

Class Method Details

.decompress_index(index, level) ⇒ Object 



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# File 'lib/unicode/display_width/index.rb', line 14

def self.decompress_index(index, level)
  index.flat_map{ |value|
    if level > 0
      if value.instance_of?(Array)
        value[15] ||= nil
        decompress_index(value, level - 1)
      else
        decompress_index([value] * 16, level - 1)
      end
    else
      if value.instance_of?(Array)
        value[15] ||= nil
        value
      else
        [value] * 16
      end
    end
  }
end

.emoji_width(string, mode = :all, ambiguous = DEFAULT_AMBIGUOUS) ⇒ Object

Returns width of all considered Emoji and remaining string



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# File 'lib/unicode/display_width.rb', line 143

def self.emoji_width(string, mode = :all, ambiguous = DEFAULT_AMBIGUOUS)
  res = 0

  if emoji_set_regex = EMOJI_SEQUENCES_REGEX_MAPPING[mode]
    emoji_width_via_possible(
      string,
      Unicode::Emoji.const_get(emoji_set_regex),
      mode == :rgi_at,
      ambiguous,
    )

  elsif mode == :all_no_vs16
    no_emoji_string = string.gsub(REGEX_EMOJI_ALL_SEQUENCES){ res += 2; "" }
    [res, no_emoji_string]

  elsif mode == :vs16
    no_emoji_string = string.gsub(REGEX_EMOJI_VS16){ res += 2; "" }
    [res, no_emoji_string]

  elsif mode == :all
    no_emoji_string = string.gsub(REGEX_EMOJI_ALL_SEQUENCES_AND_VS16){ res += 2; "" }
    [res, no_emoji_string]

  else
    [0, string]

  end
end

.emoji_width_via_possible(string, emoji_set_regex, strict_eaw = false, ambiguous = DEFAULT_AMBIGUOUS) ⇒ Object

Match possible Emoji first, then refine



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# File 'lib/unicode/display_width.rb', line 173

def self.emoji_width_via_possible(string, emoji_set_regex, strict_eaw = false, ambiguous = DEFAULT_AMBIGUOUS)
  res = 0

  # For each string possibly an emoji
  no_emoji_string = string.gsub(REGEX_EMOJI_ALL_SEQUENCES_AND_VS16){ |emoji_candidate|
    # Check if we have a combined Emoji with width 2 (or EAW an Apple Terminal)
    if emoji_candidate == emoji_candidate[emoji_set_regex]
      if strict_eaw
        res += self.of(emoji_candidate[0], ambiguous, emoji: false)
      else
        res += 2
      end
      ""

    # We are dealing with a default text presentation emoji or a well-formed sequence not matching the above Emoji set
    else
      if !strict_eaw
        # Ensure all explicit VS16 sequences have width 2
        emoji_candidate.gsub!(REGEX_EMOJI_VS16){ res += 2; "" }
      end

      emoji_candidate
    end
  }

  [res, no_emoji_string]
end

.normalize_options(string, ambiguous = nil, overwrite = nil, old_options = {}, **options) ⇒ Object 



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# File 'lib/unicode/display_width.rb', line 201

def self.normalize_options(string, ambiguous = nil, overwrite = nil, old_options = {}, **options)
  unless old_options.empty?
    warn "Unicode::DisplayWidth: Please migrate to keyword arguments - #{old_options.inspect}"
    options.merge! old_options
  end

  options[:ambiguous] = ambiguous if ambiguous
  options[:ambiguous] ||= DEFAULT_AMBIGUOUS

  if options[:ambiguous] != 1 && options[:ambiguous] != 2
    raise ArgumentError, "Unicode::DisplayWidth: Ambiguous width must be 1 or 2"
  end

  if overwrite && !overwrite.empty?
    warn "Unicode::DisplayWidth: Please migrate to keyword arguments - overwrite: #{overwrite.inspect}"
    options[:overwrite] = overwrite
  end
  options[:overwrite] ||= {}

  if [nil, true, :auto].include?(options[:emoji])
    options[:emoji] = EmojiSupport.recommended
  elsif options[:emoji] == false
    options[:emoji] = :none
  end

  options
end

.of(string, ambiguous = nil, overwrite = nil, old_options = {}, **options) ⇒ Object

Returns monospace display width of string



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# File 'lib/unicode/display_width.rb', line 51

def self.of(string, ambiguous = nil, overwrite = nil, old_options = {}, **options)
  # Binary strings don't make much sense when calculating display width.
  # Assume it's valid UTF-8
  if string.encoding == Encoding::BINARY && !string.force_encoding(Encoding::UTF_8).valid_encoding?
    # Didn't work out, go back to binary
    string.force_encoding(Encoding::BINARY)
  end

  string = string.encode(Encoding::UTF_8, invalid: :replace, undef: :replace) unless string.encoding == Encoding::UTF_8
  options = normalize_options(string, ambiguous, overwrite, old_options, **options)

  width = 0

  unless options[:overwrite].empty?
    width, string = width_custom(string, options[:overwrite])
  end

  if string.ascii_only?
    return width + width_ascii(string)
  end

  ambiguous_index_name = AMBIGUOUS_MAP[options[:ambiguous]]

  unless string.match?(NOT_COMMON_NARROW_REGEX[ambiguous_index_name])
    return width + string.size
  end

  # Retrieve Emoji width
  if options[:emoji] != :none
    e_width, string = emoji_width(
      string,
      options[:emoji],
      options[:ambiguous],
    )
    width += e_width

    unless string.match?(NOT_COMMON_NARROW_REGEX[ambiguous_index_name])
      return width + string.size
    end
  end

  index_full = INDEX[ambiguous_index_name]
  index_low = FIRST_4096[ambiguous_index_name]
  first_ambiguous = FIRST_AMBIGUOUS[ambiguous_index_name]

  string.each_codepoint{ |codepoint|
    if codepoint > 15 && codepoint < first_ambiguous
      width += 1
    elsif codepoint < 0x1001
      width += index_low[codepoint] || 1
    else
      d = INITIAL_DEPTH
      w = index_full[codepoint / d]
      while w.instance_of? Array
        w = w[(codepoint %= d) / (d /= 16)]
      end

      width += w || 1
    end
  }

  # Return result + prevent negative lengths
  width < 0 ? 0 : width
end

.width_ascii(string) ⇒ Object

Returns width for ASCII-only strings. Will consider zero-width control symbols.



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# File 'lib/unicode/display_width.rb', line 133

def self.width_ascii(string)
  if string.match?(ASCII_NON_ZERO_REGEX)
    res = string.delete(ASCII_NON_ZERO_STRING).bytesize - string.count(ASCII_BACKSPACE)
    return res < 0 ? 0 : res
  end

  string.bytesize
end

.width_custom(string, overwrite) ⇒ Object

Returns width of custom overwrites and remaining string



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# File 'lib/unicode/display_width.rb', line 117

def self.width_custom(string, overwrite)
  width = 0

  string = string.each_codepoint.select{ |codepoint|
    if overwrite[codepoint]
      width += overwrite[codepoint]
      nil
    else
      codepoint
    end
  }.pack("U*")

  [width, string]
end

Instance Method Details

#get_config(**kwargs) ⇒ Object 



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# File 'lib/unicode/display_width.rb', line 235

def get_config(**kwargs)
  {
    ambiguous: kwargs[:ambiguous] || @ambiguous,
    overwrite: kwargs[:overwrite] || @overwrite,
    emoji:     kwargs[:emoji]     || @emoji,
  }
end

#of(string, **kwargs) ⇒ Object 



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# File 'lib/unicode/display_width.rb', line 243

def of(string, **kwargs)
  self.class.of(string, **get_config(**kwargs))
end