lib/core_ext/multibyte/unicode.rb
module CoreExt
module Multibyte
module Unicode
extend self
# A list of all available normalization forms.
# See http://www.unicode.org/reports/tr15/tr15-29.html for more
# information about normalization.
NORMALIZATION_FORMS = [:c, :kc, :d, :kd]
# The Unicode version that is supported by the implementation
UNICODE_VERSION = '8.0.0'
# The default normalization used for operations that require
# normalization. It can be set to any of the normalizations
# in NORMALIZATION_FORMS.
#
# CoreExt::Multibyte::Unicode.default_normalization_form = :c
attr_accessor :default_normalization_form
@default_normalization_form = :kc
# Hangul character boundaries and properties
HANGUL_SBASE = 0xAC00
HANGUL_LBASE = 0x1100
HANGUL_VBASE = 0x1161
HANGUL_TBASE = 0x11A7
HANGUL_LCOUNT = 19
HANGUL_VCOUNT = 21
HANGUL_TCOUNT = 28
HANGUL_NCOUNT = HANGUL_VCOUNT * HANGUL_TCOUNT
HANGUL_SCOUNT = 11172
HANGUL_SLAST = HANGUL_SBASE + HANGUL_SCOUNT
HANGUL_JAMO_FIRST = 0x1100
HANGUL_JAMO_LAST = 0x11FF
# All the unicode whitespace
WHITESPACE = [
(0x0009..0x000D).to_a, # White_Space # Cc [5] <control-0009>..<control-000D>
0x0020, # White_Space # Zs SPACE
0x0085, # White_Space # Cc <control-0085>
0x00A0, # White_Space # Zs NO-BREAK SPACE
0x1680, # White_Space # Zs OGHAM SPACE MARK
(0x2000..0x200A).to_a, # White_Space # Zs [11] EN QUAD..HAIR SPACE
0x2028, # White_Space # Zl LINE SEPARATOR
0x2029, # White_Space # Zp PARAGRAPH SEPARATOR
0x202F, # White_Space # Zs NARROW NO-BREAK SPACE
0x205F, # White_Space # Zs MEDIUM MATHEMATICAL SPACE
0x3000, # White_Space # Zs IDEOGRAPHIC SPACE
].flatten.freeze
# BOM (byte order mark) can also be seen as whitespace, it's a
# non-rendering character used to distinguish between little and big
# endian. This is not an issue in utf-8, so it must be ignored.
LEADERS_AND_TRAILERS = WHITESPACE + [65279] # ZERO-WIDTH NO-BREAK SPACE aka BOM
# Returns a regular expression pattern that matches the passed Unicode
# codepoints.
def self.codepoints_to_pattern(array_of_codepoints) #:nodoc:
array_of_codepoints.collect{ |e| [e].pack 'U*'.freeze }.join('|'.freeze)
end
TRAILERS_PAT = /(#{codepoints_to_pattern(LEADERS_AND_TRAILERS)})+\Z/u
LEADERS_PAT = /\A(#{codepoints_to_pattern(LEADERS_AND_TRAILERS)})+/u
# Detect whether the codepoint is in a certain character class. Returns
# +true+ when it's in the specified character class and +false+ otherwise.
# Valid character classes are: <tt>:cr</tt>, <tt>:lf</tt>, <tt>:l</tt>,
# <tt>:v</tt>, <tt>:lv</tt>, <tt>:lvt</tt> and <tt>:t</tt>.
#
# Primarily used by the grapheme cluster support.
def in_char_class?(codepoint, classes)
classes.detect { |c| database.boundary[c] === codepoint } ? true : false
end
# Unpack the string at grapheme boundaries. Returns a list of character
# lists.
#
# Unicode.unpack_graphemes('क्षि') # => [[2325, 2381], [2359], [2367]]
# Unicode.unpack_graphemes('Café') # => [[67], [97], [102], [233]]
def unpack_graphemes(string)
codepoints = string.codepoints.to_a
unpacked = []
pos = 0
marker = 0
eoc = codepoints.length
while(pos < eoc)
pos += 1
previous = codepoints[pos-1]
current = codepoints[pos]
if (
# CR X LF
( previous == database.boundary[:cr] and current == database.boundary[:lf] ) or
# L X (L|V|LV|LVT)
( database.boundary[:l] === previous and in_char_class?(current, [:l,:v,:lv,:lvt]) ) or
# (LV|V) X (V|T)
( in_char_class?(previous, [:lv,:v]) and in_char_class?(current, [:v,:t]) ) or
# (LVT|T) X (T)
( in_char_class?(previous, [:lvt,:t]) and database.boundary[:t] === current ) or
# X Extend
(database.boundary[:extend] === current)
)
else
unpacked << codepoints[marker..pos-1]
marker = pos
end
end
unpacked
end
# Reverse operation of unpack_graphemes.
#
# Unicode.pack_graphemes(Unicode.unpack_graphemes('क्षि')) # => 'क्षि'
def pack_graphemes(unpacked)
unpacked.flatten.pack('U*')
end
# Re-order codepoints so the string becomes canonical.
def reorder_characters(codepoints)
length = codepoints.length- 1
pos = 0
while pos < length do
cp1, cp2 = database.codepoints[codepoints[pos]], database.codepoints[codepoints[pos+1]]
if (cp1.combining_class > cp2.combining_class) && (cp2.combining_class > 0)
codepoints[pos..pos+1] = cp2.code, cp1.code
pos += (pos > 0 ? -1 : 1)
else
pos += 1
end
end
codepoints
end
# Decompose composed characters to the decomposed form.
def decompose(type, codepoints)
codepoints.inject([]) do |decomposed, cp|
# if it's a hangul syllable starter character
if HANGUL_SBASE <= cp and cp < HANGUL_SLAST
sindex = cp - HANGUL_SBASE
ncp = [] # new codepoints
ncp << HANGUL_LBASE + sindex / HANGUL_NCOUNT
ncp << HANGUL_VBASE + (sindex % HANGUL_NCOUNT) / HANGUL_TCOUNT
tindex = sindex % HANGUL_TCOUNT
ncp << (HANGUL_TBASE + tindex) unless tindex == 0
decomposed.concat ncp
# if the codepoint is decomposable in with the current decomposition type
elsif (ncp = database.codepoints[cp].decomp_mapping) and (!database.codepoints[cp].decomp_type || type == :compatibility)
decomposed.concat decompose(type, ncp.dup)
else
decomposed << cp
end
end
end
# Compose decomposed characters to the composed form.
def compose(codepoints)
pos = 0
eoa = codepoints.length - 1
starter_pos = 0
starter_char = codepoints[0]
previous_combining_class = -1
while pos < eoa
pos += 1
lindex = starter_char - HANGUL_LBASE
# -- Hangul
if 0 <= lindex and lindex < HANGUL_LCOUNT
vindex = codepoints[starter_pos+1] - HANGUL_VBASE rescue vindex = -1
if 0 <= vindex and vindex < HANGUL_VCOUNT
tindex = codepoints[starter_pos+2] - HANGUL_TBASE rescue tindex = -1
if 0 <= tindex and tindex < HANGUL_TCOUNT
j = starter_pos + 2
eoa -= 2
else
tindex = 0
j = starter_pos + 1
eoa -= 1
end
codepoints[starter_pos..j] = (lindex * HANGUL_VCOUNT + vindex) * HANGUL_TCOUNT + tindex + HANGUL_SBASE
end
starter_pos += 1
starter_char = codepoints[starter_pos]
# -- Other characters
else
current_char = codepoints[pos]
current = database.codepoints[current_char]
if current.combining_class > previous_combining_class
if ref = database.composition_map[starter_char]
composition = ref[current_char]
else
composition = nil
end
unless composition.nil?
codepoints[starter_pos] = composition
starter_char = composition
codepoints.delete_at pos
eoa -= 1
pos -= 1
previous_combining_class = -1
else
previous_combining_class = current.combining_class
end
else
previous_combining_class = current.combining_class
end
if current.combining_class == 0
starter_pos = pos
starter_char = codepoints[pos]
end
end
end
codepoints
end
# Rubinius' String#scrub, however, doesn't support ASCII-incompatible chars.
if !defined?(Rubinius)
# Replaces all ISO-8859-1 or CP1252 characters by their UTF-8 equivalent
# resulting in a valid UTF-8 string.
#
# Passing +true+ will forcibly tidy all bytes, assuming that the string's
# encoding is entirely CP1252 or ISO-8859-1.
def tidy_bytes(string, force = false)
return string if string.empty?
return recode_windows1252_chars(string) if force
string.scrub { |bad| recode_windows1252_chars(bad) }
end
else
def tidy_bytes(string, force = false)
return string if string.empty?
return recode_windows1252_chars(string) if force
# We can't transcode to the same format, so we choose a nearly-identical encoding.
# We're going to 'transcode' bytes from UTF-8 when possible, then fall back to
# CP1252 when we get errors. The final string will be 'converted' back to UTF-8
# before returning.
reader = Encoding::Converter.new(Encoding::UTF_8, Encoding::UTF_16LE)
source = string.dup
out = ''.force_encoding(Encoding::UTF_16LE)
loop do
reader.primitive_convert(source, out)
_, _, _, error_bytes, _ = reader.primitive_errinfo
break if error_bytes.nil?
out << error_bytes.encode(Encoding::UTF_16LE, Encoding::Windows_1252, invalid: :replace, undef: :replace)
end
reader.finish
out.encode!(Encoding::UTF_8)
end
end
# Returns the KC normalization of the string by default. NFKC is
# considered the best normalization form for passing strings to databases
# and validations.
#
# * <tt>string</tt> - The string to perform normalization on.
# * <tt>form</tt> - The form you want to normalize in. Should be one of
# the following: <tt>:c</tt>, <tt>:kc</tt>, <tt>:d</tt>, or <tt>:kd</tt>.
# Default is CoreExt::Multibyte::Unicode.default_normalization_form.
def normalize(string, form=nil)
form ||= @default_normalization_form
# See http://www.unicode.org/reports/tr15, Table 1
codepoints = string.codepoints.to_a
case form
when :d
reorder_characters(decompose(:canonical, codepoints))
when :c
compose(reorder_characters(decompose(:canonical, codepoints)))
when :kd
reorder_characters(decompose(:compatibility, codepoints))
when :kc
compose(reorder_characters(decompose(:compatibility, codepoints)))
else
raise ArgumentError, "#{form} is not a valid normalization variant", caller
end.pack('U*'.freeze)
end
def downcase(string)
apply_mapping string, :lowercase_mapping
end
def upcase(string)
apply_mapping string, :uppercase_mapping
end
def swapcase(string)
apply_mapping string, :swapcase_mapping
end
# Holds data about a codepoint in the Unicode database.
class Codepoint
attr_accessor :code, :combining_class, :decomp_type, :decomp_mapping, :uppercase_mapping, :lowercase_mapping
# Initializing Codepoint object with default values
def initialize
@combining_class = 0
@uppercase_mapping = 0
@lowercase_mapping = 0
end
def swapcase_mapping
uppercase_mapping > 0 ? uppercase_mapping : lowercase_mapping
end
end
# Holds static data from the Unicode database.
class UnicodeDatabase
ATTRIBUTES = :codepoints, :composition_exclusion, :composition_map, :boundary, :cp1252
attr_writer(*ATTRIBUTES)
def initialize
@codepoints = Hash.new(Codepoint.new)
@composition_exclusion = []
@composition_map = {}
@boundary = {}
@cp1252 = {}
end
# Lazy load the Unicode database so it's only loaded when it's actually used
ATTRIBUTES.each do |attr_name|
class_eval(<<-EOS, __FILE__, __LINE__ + 1)
def #{attr_name} # def codepoints
load # load
@#{attr_name} # @codepoints
end # end
EOS
end
# Loads the Unicode database and returns all the internal objects of
# UnicodeDatabase.
def load
begin
@codepoints, @composition_exclusion, @composition_map, @boundary, @cp1252 = File.open(self.class.filename, 'rb') { |f| Marshal.load f.read }
rescue => e
raise IOError.new("Couldn't load the Unicode tables for UTF8Handler (#{e.message}), CoreExt::Multibyte is unusable")
end
# Redefine the === method so we can write shorter rules for grapheme cluster breaks
@boundary.each_key do |k|
@boundary[k].instance_eval do
def ===(other)
detect { |i| i === other } ? true : false
end
end if @boundary[k].kind_of?(Array)
end
# define attr_reader methods for the instance variables
class << self
attr_reader(*ATTRIBUTES)
end
end
# Returns the directory in which the data files are stored.
def self.dirname
File.dirname(__FILE__) + '/../values/'
end
# Returns the filename for the data file for this version.
def self.filename
File.expand_path File.join(dirname, "unicode_tables.dat")
end
end
private
def apply_mapping(string, mapping) #:nodoc:
database.codepoints
string.each_codepoint.map do |codepoint|
cp = database.codepoints[codepoint]
if cp and (ncp = cp.send(mapping)) and ncp > 0
ncp
else
codepoint
end
end.pack('U*')
end
def recode_windows1252_chars(string)
string.encode(Encoding::UTF_8, Encoding::Windows_1252, invalid: :replace, undef: :replace)
end
def database
@database ||= UnicodeDatabase.new
end
end
end
end