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# Contains all the handlers and helper classes
module ActiveSupport::Multibyte::Handlers
class EncodingError < ArgumentError; end
class Codepoint #:nodoc:
attr_accessor :code, :combining_class, :decomp_type, :decomp_mapping, :uppercase_mapping, :lowercase_mapping
end
class UnicodeDatabase #:nodoc:
attr_writer :codepoints, :composition_exclusion, :composition_map, :boundary, :cp1252
# self-expiring methods that lazily load the Unicode database and then return the value.
[:codepoints, :composition_exclusion, :composition_map, :boundary, :cp1252].each do |attr_name|
class_eval(<<-EOS, __FILE__, __LINE__)
def #{attr_name}
load
@#{attr_name}
end
EOS
end
# Shortcut to ucd.codepoints[]
def [](index); codepoints[index]; 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
# Loads the unicode database and returns all the internal objects of UnicodeDatabase
# Once the values have been loaded, define attr_reader methods for the instance variables.
def load
begin
@codepoints, @composition_exclusion, @composition_map, @boundary, @cp1252 = File.open(self.class.filename, 'rb') { |f| Marshal.load f.read }
rescue Exception => e
raise IOError.new("Couldn't load the unicode tables for UTF8Handler (#{e.message}), handler is unusable")
end
@codepoints ||= Hash.new(Codepoint.new)
@composition_exclusion ||= []
@composition_map ||= {}
@boundary ||= {}
@cp1252 ||= {}
# Redefine the === method so we can write shorter rules for grapheme cluster breaks
@boundary.each 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 :codepoints, :composition_exclusion, :composition_map, :boundary, :cp1252
end
end
end
# UTF8Handler implements Unicode aware operations for strings, these operations will be used by the Chars
# proxy when $KCODE is set to 'UTF8'.
class UTF8Handler
# 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
UNICODE_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
0x180E, # White_Space # Zs MONGOLIAN VOWEL SEPARATOR
(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.
UNICODE_LEADERS_AND_TRAILERS = UNICODE_WHITESPACE + [65279] # ZERO-WIDTH NO-BREAK SPACE aka BOM
# Borrowed from the Kconv library by Shinji KONO - (also as seen on the W3C site)
UTF8_PAT = /\A(?:
[\x00-\x7f] |
[\xc2-\xdf] [\x80-\xbf] |
\xe0 [\xa0-\xbf] [\x80-\xbf] |
[\xe1-\xef] [\x80-\xbf] [\x80-\xbf] |
\xf0 [\x90-\xbf] [\x80-\xbf] [\x80-\xbf] |
[\xf1-\xf3] [\x80-\xbf] [\x80-\xbf] [\x80-\xbf] |
\xf4 [\x80-\x8f] [\x80-\xbf] [\x80-\xbf]
)*\z/xn
# 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*' }.join('|')
end
UNICODE_TRAILERS_PAT = /(#{codepoints_to_pattern(UNICODE_LEADERS_AND_TRAILERS)})+\Z/
UNICODE_LEADERS_PAT = /\A(#{codepoints_to_pattern(UNICODE_LEADERS_AND_TRAILERS)})+/
class << self
# ///
# /// BEGIN String method overrides
# ///
# Inserts the passed string at specified codepoint offsets
def insert(str, offset, fragment)
str.replace(
u_unpack(str).insert(
offset,
u_unpack(fragment)
).flatten.pack('U*')
)
end
# Returns the position of the passed argument in the string, counting in codepoints
def index(str, *args)
bidx = str.index(*args)
bidx ? (u_unpack(str.slice(0...bidx)).size) : nil
end
# Does Unicode-aware rstrip
def rstrip(str)
str.gsub(UNICODE_TRAILERS_PAT, '')
end
# Does Unicode-aware lstrip
def lstrip(str)
str.gsub(UNICODE_LEADERS_PAT, '')
end
# Removed leading and trailing whitespace
def strip(str)
str.gsub(UNICODE_LEADERS_PAT, '').gsub(UNICODE_TRAILERS_PAT, '')
end
# Returns the number of codepoints in the string
def size(str)
u_unpack(str).size
end
alias_method :length, :size
# Reverses codepoints in the string.
def reverse(str)
u_unpack(str).reverse.pack('U*')
end
# Implements Unicode-aware slice with codepoints. Slicing on one point returns the codepoints for that
# character.
def slice(str, *args)
if (args.size == 2 && args.first.is_a?(Range))
raise TypeError, 'cannot convert Range into Integer' # Do as if we were native
elsif args[0].kind_of? Range
cps = u_unpack(str).slice(*args)
cps.nil? ? nil : cps.pack('U*')
elsif args.size == 1 && args[0].kind_of?(Numeric)
u_unpack(str)[args[0]]
else
u_unpack(str).slice(*args).pack('U*')
end
end
alias_method :[], :slice
# Convert characters in the string to uppercase
def upcase(str); to_case :uppercase_mapping, str; end
# Convert characters in the string to lowercase
def downcase(str); to_case :lowercase_mapping, str; end
# Returns a copy of +str+ with the first character converted to uppercase and the remainder to lowercase
def capitalize(str)
upcase(slice(str, 0..0)) + downcase(slice(str, 1..-1) || '')
end
# ///
# /// Extra String methods for unicode operations
# ///
# Returns the KC normalization of the string by default. NFKC is considered the best normalization form for
# passing strings to databases and validations.
#
# * <tt>str</tt>: The string to perform normalization on.
# * <tt>form</tt>: The form you want to normalize in. Should be one of the following: :c, :kc, :d or :kd.
def normalize(str, form=ActiveSupport::Multibyte::DEFAULT_NORMALIZATION_FORM)
# See http://www.unicode.org/reports/tr15, Table 1
codepoints = u_unpack(str)
case form
when :d
reorder_characters(decompose_codepoints(:canonical, codepoints))
when :c
compose_codepoints reorder_characters(decompose_codepoints(:canonical, codepoints))
when :kd
reorder_characters(decompose_codepoints(:compatability, codepoints))
when :kc
compose_codepoints reorder_characters(decompose_codepoints(:compatability, codepoints))
else
raise ArgumentError, "#{form} is not a valid normalization variant", caller
end.pack('U*')
end
# Perform decomposition on the characters in the string
def decompose(str)
decompose_codepoints(:canonical, u_unpack(str)).pack('U*')
end
# Perform composition on the characters in the string
def compose(str)
compose_codepoints u_unpack(str).pack('U*')
end
# ///
# /// BEGIN Helper methods for unicode operation
# ///
# Used to translate an offset from bytes to characters, for instance one received from a regular expression match
def translate_offset(str, byte_offset)
return 0 if str == ''
return nil if byte_offset.nil?
chunk = str[0..byte_offset]
begin
begin
chunk.unpack('U*').length - 1
rescue ArgumentError => e
chunk = str[0..(byte_offset+=1)]
# Stop retrying at the end of the string
raise e unless byte_offset < chunk.length
# We damaged a character, retry
retry
end
# Catch the ArgumentError so we can throw our own
rescue ArgumentError
raise EncodingError.new('malformed UTF-8 character')
end
end
# Checks if the string is valid UTF8.
def consumes?(str)
# Unpack is a little bit faster than regular expressions
begin
str.unpack('U*')
true
rescue ArgumentError
false
end
end
# Returns the number of grapheme clusters in the string. This method is very likely to be moved or renamed
# in future versions.
def g_length(str)
g_unpack(str).length
end
# Replaces all the non-utf-8 bytes by their iso-8859-1 or cp1252 equivalent resulting in a valid utf-8 string
def tidy_bytes(str)
str.split(//u).map do |c|
if !UTF8_PAT.match(c)
n = c.unpack('C')[0]
n < 128 ? n.chr :
n < 160 ? [UCD.cp1252[n] || n].pack('U') :
n < 192 ? "\xC2" + n.chr : "\xC3" + (n-64).chr
else
c
end
end.join
end
protected
# Detect whether the codepoint is in a certain character class. Primarily used by the
# grapheme cluster support.
def in_char_class?(codepoint, classes)
classes.detect { |c| UCD.boundary[c] === codepoint } ? true : false
end
# Unpack the string at codepoints boundaries
def u_unpack(str)
begin
str.unpack 'U*'
rescue ArgumentError
raise EncodingError.new('malformed UTF-8 character')
end
end
# Unpack the string at grapheme boundaries instead of codepoint boundaries
def g_unpack(str)
codepoints = u_unpack(str)
unpacked = []
pos = 0
marker = 0
eoc = codepoints.length
while(pos < eoc)
pos += 1
previous = codepoints[pos-1]
current = codepoints[pos]
if (
# CR X LF
one = ( previous == UCD.boundary[:cr] and current == UCD.boundary[:lf] ) or
# L X (L|V|LV|LVT)
two = ( UCD.boundary[:l] === previous and in_char_class?(current, [:l,:v,:lv,:lvt]) ) or
# (LV|V) X (V|T)
three = ( in_char_class?(previous, [:lv,:v]) and in_char_class?(current, [:v,:t]) ) or
# (LVT|T) X (T)
four = ( in_char_class?(previous, [:lvt,:t]) and UCD.boundary[:t] === current ) or
# X Extend
five = (UCD.boundary[:extend] === current)
)
else
unpacked << codepoints[marker..pos-1]
marker = pos
end
end
unpacked
end
# Reverse operation of g_unpack
def g_pack(unpacked)
unpacked.flatten
end
# Convert characters to a different case
def to_case(way, str)
u_unpack(str).map do |codepoint|
cp = UCD[codepoint]
unless cp.nil?
ncp = cp.send(way)
ncp > 0 ? ncp : codepoint
else
codepoint
end
end.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 = UCD[codepoints[pos]], UCD[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_codepoints(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 = UCD[cp].decomp_mapping) and (!UCD[cp].decomp_type || type == :compatability)
decomposed.concat decompose_codepoints(type, ncp.dup)
else
decomposed << cp
end
end
end
# Compose decomposed characters to the composed form
def compose_codepoints(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 = UCD[current_char]
if current.combining_class > previous_combining_class
if ref = UCD.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
# UniCode Database
UCD = UnicodeDatabase.new
end
end
end
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