Flex (lexer) - 匹配 unicode
Flex (lexer) - matching unicode
有没有办法让 flex 按照
的方式匹配 unicode
ascSymbol !|#|$|%|&|⋆|+|.|/|<|=|>|?|@|\|^|-|~|:
uniSymbol \p{Symbol}|\p{Other_Symbol}|\p{Punctuation}
symbol ascSymbol|uniSymbol{-}[^|_"',;]
我找到了 http://lists.gnu.org/archive/html/help-flex/2005-01/msg00043.html via Flex(lexer) support for unicode，但我希望能够以自动化的方式进行某些操作。
例如，我正在使用 cmake，它被配置为从 *.l 和 *.y 文件生成 lexer/parser。理想情况下，我想要一个不需要安装 GHC 或其他 Haskell 编译器的解决方法。
也愿意接受有关与 Bison 集成并支持 unicode 的另一个词法分析器的建议....
事实证明，在 Flex 中获得 unicode 支持会很痛苦，除非 Flex 源本身添加它。那里似乎有一些针对 unicode 的实验性内容，但从未将其发布到我能找到的版本中。
Ragel doc is insightful, and comes with built in support for Unicode. I've since found this article 给出了如何使 Ragel 和 C++ 更好地配合使用的示例。似乎是更好的选择，所以就这样吧。
希望这可以节省其他人解决这个问题的时间。
编辑
"Built in support" 上面说的可能有点夸张。获得 unicode 支持变得更加容易，但它不仅仅是开箱即用的东西。
我使用 cmake 从派生的 UCD 7 文件生成状态机。
在 CMakeLists.txt 我做：
#Ruby is required to generate a unicode Ragel machine
FIND_PACKAGE(Ruby REQUIRED)
MESSAGE("Found Ruby ${RUBY_VERSION}")
SET(UNICODE_MACHINE_PATH "${PROJECT_SOURCE_DIR}/src/unicode.rl")
if(NOT EXISTS ${UNICODE_MACHINE_PATH} OR gen_unicode)
MESSAGE("Attempting to generate unicode state machine")
EXECUTE_PROCESS(COMMAND ${RUBY_EXECUTABLE} ${PROJECT_SOURCE_DIR}/unicode2ragel.rb
OUTPUT_FILE ${UNICODE_MACHINE_PATH}
RESULT_VARIABLE RAGEL_UNICODE_GEN_RES)
if(${RAGEL_UNICODE_GEN_RES} EQUAL 0)
MESSAGE("Generaged Ragel Unicode state machine")
else()
MESSAGE(SEND_ERROR "Unable to generate unicode state machine")
endif()
endif()
然后在 unicode2ragel.rb（与 Ragel 一起发布并针对 UCD 7 稍作修改）
#!/usr/bin/env ruby
#
# This script uses the unicode spec to generate a Ragel state machine
# that recognizes unicode alphanumeric characters. It generates 5
# character classes: uupper, ulower, ualpha, udigit, and ualnum.
# Currently supported encodings are UTF-8 [default] and UCS-4.
#
# Usage: unicode2ragel.rb [options]
# -e, --encoding [ucs4 | utf8] Data encoding
# -h, --help Show this message
#
# This script was originally written as part of the Ferret search
# engine library.
#
# Author: Rakan El-Khalil <rakan@well.com>
require 'optparse'
require 'open-uri'
ENCODINGS = [ :utf8, :ucs4 ]
ALPHTYPES = { :utf8 => "unsigned char", :ucs4 => "unsigned int" }
CHART_URL = "http://www.unicode.org/Public/7.0.0/ucd/extracted/DerivedGeneralCategory.txt"#"http://www.unicode.org/Public/7.0.0/ucd/DerivedCoreProperties.txt"
###
# Display vars & default option
TOTAL_WIDTH = 80
RANGE_WIDTH = 23
@encoding = :utf8
###
# Option parsing
cli_opts = OptionParser.new do |opts|
opts.on("-e", "--encoding [ucs4 | utf8]", "Data encoding") do |o|
@encoding = o.downcase.to_sym
end
opts.on("-h", "--help", "Show this message") do
puts opts
exit
end
end
cli_opts.parse(ARGV)
unless ENCODINGS.member? @encoding
puts "Invalid encoding: #{@encoding}"
puts cli_opts
exit
end
##
# Downloads the document at url and yields every alpha line's hex
# range and description.
def each_alpha( url, property )
open( url ) do |file|
file.each_line do |line|
next if line =~ /^#/;
next if line !~ /; #{property} #/;
range, description = line.split(/;/)
range.strip!
description.gsub!(/.*#/, '').strip!
if range =~ /\.\./
start, stop = range.split '..'
else start = stop = range
end
yield start.hex .. stop.hex, description
end
end
end
###
# Formats to hex at minimum width
def to_hex( n )
r = "%0X" % n
r = "0#{r}" unless (r.length % 2).zero?
r
end
###
# UCS4 is just a straight hex conversion of the unicode codepoint.
def to_ucs4( range )
rangestr = "0x" + to_hex(range.begin)
rangestr << "..0x" + to_hex(range.end) if range.begin != range.end
[ rangestr ]
end
##
# 0x00 - 0x7f -> 0zzzzzzz[7]
# 0x80 - 0x7ff -> 110yyyyy[5] 10zzzzzz[6]
# 0x800 - 0xffff -> 1110xxxx[4] 10yyyyyy[6] 10zzzzzz[6]
# 0x010000 - 0x10ffff -> 11110www[3] 10xxxxxx[6] 10yyyyyy[6] 10zzzzzz[6]
UTF8_BOUNDARIES = [0x7f, 0x7ff, 0xffff, 0x10ffff]
def to_utf8_enc( n )
r = 0
if n <= 0x7f
r = n
elsif n <= 0x7ff
y = 0xc0 | (n >> 6)
z = 0x80 | (n & 0x3f)
r = y << 8 | z
elsif n <= 0xffff
x = 0xe0 | (n >> 12)
y = 0x80 | (n >> 6) & 0x3f
z = 0x80 | n & 0x3f
r = x << 16 | y << 8 | z
elsif n <= 0x10ffff
w = 0xf0 | (n >> 18)
x = 0x80 | (n >> 12) & 0x3f
y = 0x80 | (n >> 6) & 0x3f
z = 0x80 | n & 0x3f
r = w << 24 | x << 16 | y << 8 | z
end
to_hex(r)
end
def from_utf8_enc( n )
n = n.hex
r = 0
if n <= 0x7f
r = n
elsif n <= 0xdfff
y = (n >> 8) & 0x1f
z = n & 0x3f
r = y << 6 | z
elsif n <= 0xefffff
x = (n >> 16) & 0x0f
y = (n >> 8) & 0x3f
z = n & 0x3f
r = x << 10 | y << 6 | z
elsif n <= 0xf7ffffff
w = (n >> 24) & 0x07
x = (n >> 16) & 0x3f
y = (n >> 8) & 0x3f
z = n & 0x3f
r = w << 18 | x << 12 | y << 6 | z
end
r
end
###
# Given a range, splits it up into ranges that can be continuously
# encoded into utf8. Eg: 0x00 .. 0xff => [0x00..0x7f, 0x80..0xff]
# This is not strictly needed since the current [5.1] unicode standard
# doesn't have ranges that straddle utf8 boundaries. This is included
# for completeness as there is no telling if that will ever change.
def utf8_ranges( range )
ranges = []
UTF8_BOUNDARIES.each do |max|
if range.begin <= max
return ranges << range if range.end <= max
ranges << range.begin .. max
range = (max + 1) .. range.end
end
end
ranges
end
def build_range( start, stop )
size = start.size/2
left = size - 1
return [""] if size < 1
a = start[0..1]
b = stop[0..1]
###
# Shared prefix
if a == b
return build_range(start[2..-1], stop[2..-1]).map do |elt|
"0x#{a} " + elt
end
end
###
# Unshared prefix, end of run
return ["0x#{a}..0x#{b} "] if left.zero?
###
# Unshared prefix, not end of run
# Range can be 0x123456..0x56789A
# Which is equivalent to:
# 0x123456 .. 0x12FFFF
# 0x130000 .. 0x55FFFF
# 0x560000 .. 0x56789A
ret = []
ret << build_range(start, a + "FF" * left)
###
# Only generate middle range if need be.
if a.hex+1 != b.hex
max = to_hex(b.hex - 1)
max = "FF" if b == "FF"
ret << "0x#{to_hex(a.hex+1)}..0x#{max} " + "0x00..0xFF " * left
end
###
# Don't generate last range if it is covered by first range
ret << build_range(b + "00" * left, stop) unless b == "FF"
ret.flatten!
end
def to_utf8( range )
utf8_ranges( range ).map do |r|
build_range to_utf8_enc(r.begin), to_utf8_enc(r.end)
end.flatten!
end
##
# Perform a 3-way comparison of the number of codepoints advertised by
# the unicode spec for the given range, the originally parsed range,
# and the resulting utf8 encoded range.
def count_codepoints( code )
code.split(' ').inject(1) do |acc, elt|
if elt =~ /0x(.+)\.\.0x(.+)/
if @encoding == :utf8
acc * (from_utf8_enc() - from_utf8_enc() + 1)
else
acc * (.hex - .hex + 1)
end
else
acc
end
end
end
def is_valid?( range, desc, codes )
spec_count = 1
spec_count = .to_i if desc =~ /\[(\d+)\]/
range_count = range.end - range.begin + 1
sum = codes.inject(0) { |acc, elt| acc + count_codepoints(elt) }
sum == spec_count and sum == range_count
end
##
# Generate the state maching to stdout
def generate_machine( name, property )
pipe = " "
puts " #{name} = "
each_alpha( CHART_URL, property ) do |range, desc|
codes = (@encoding == :ucs4) ? to_ucs4(range) : to_utf8(range)
raise "Invalid encoding of range #{range}: #{codes.inspect}" unless
is_valid? range, desc, codes
range_width = codes.map { |a| a.size }.max
range_width = RANGE_WIDTH if range_width < RANGE_WIDTH
desc_width = TOTAL_WIDTH - RANGE_WIDTH - 11
desc_width -= (range_width - RANGE_WIDTH) if range_width > RANGE_WIDTH
if desc.size > desc_width
desc = desc[0..desc_width - 4] + "..."
end
codes.each_with_index do |r, idx|
desc = "" unless idx.zero?
code = "%-#{range_width}s" % r
puts " #{pipe} #{code} ##{desc}"
pipe = "|"
end
end
puts " ;"
puts ""
end
puts <<EOF
# The following Ragel file was autogenerated from: #{CHART_URL}
#
# It defines ualpha, udigit, ualnum.
#
# To use this, make sure that your alphtype is set to #{ALPHTYPES[@encoding]},
# and that your input is in #{@encoding}.
%%{
machine WChar;
EOF
generate_machine( :uUppercaseLetter, "Lu" )
generate_machine( :uLowercaseLetter, "Ll" )
generate_machine( :uTitlecaseLetter, "Lt" )
generate_machine( :uModifierLetter, "Lm" )
generate_machine( :uOtherLetter, "Lo" )
generate_machine( :uNonspacingMark, "Mn" )
generate_machine( :uEnclosingMark, "Me" )
generate_machine( :uSpacingMark, "Mc" )
generate_machine( :uDecimalNumber, "Nd" )
generate_machine( :uLetterNumber, "Nl" )
generate_machine( :uOtherNumber, "No" )
generate_machine( :uSpaceSeparator, "Zs" )
generate_machine( :uLineSeparator, "Zl" )
generate_machine( :uParagraphSeparator, "Zp" )
generate_machine( :uFormat, "Cf" )
generate_machine( :uPrivateUse, "Co" )
generate_machine( :uSurrogate, "Cs" )
generate_machine( :uDashPunctuation, "Pd" )
generate_machine( :uOpenPunctuation, "Ps" )
generate_machine( :uClosePunctuation, "Pe" )
generate_machine( :uConnectorPunctuation, "Pc" )
generate_machine( :uOtherPunctuation, "Po" )
generate_machine( :uMathSymbol, "Sm" )
generate_machine( :uCurrencySymbol, "Sc" )
generate_machine( :uModifierSymbol, "Sk" )
generate_machine( :uOtherSymbol, "So" )
generate_machine( :uInitialPunctuation, "Pi" )
generate_machine( :uFinalPunctuation, "Pf" )
puts <<EOF
}%%
EOF
然后在您的 ragel 机器文件中，您可以包含 unicode.rl 并访问定义的每个 unicode 组，例如 uUppercaseLetter 等等...
"Also open to suggestions for another lexer that integrates with Bison
and has unicode support...."
RE/flex project 为 C++ 提供了一个兼容 Flex 的词法分析器生成器，它支持 Unicode 并与 Bison 一起工作。
它接受您的示例（稍作修改，以修复语法）：
%option unicode
ascSymbol [!#$%&⋆+./<=>?@\^\-~:]
uniSymbol [\p{Symbol}\p{Other_Symbol}\p{Punctuation}]{-}[\^|_"',;]
symbol {ascSymbol}|{uniSymbol}
有没有办法让 flex 按照
的方式匹配 unicodeascSymbol !|#|$|%|&|⋆|+|.|/|<|=|>|?|@|\|^|-|~|:
uniSymbol \p{Symbol}|\p{Other_Symbol}|\p{Punctuation}
symbol ascSymbol|uniSymbol{-}[^|_"',;]
我找到了 http://lists.gnu.org/archive/html/help-flex/2005-01/msg00043.html via Flex(lexer) support for unicode，但我希望能够以自动化的方式进行某些操作。
例如，我正在使用 cmake，它被配置为从 *.l 和 *.y 文件生成 lexer/parser。理想情况下，我想要一个不需要安装 GHC 或其他 Haskell 编译器的解决方法。
也愿意接受有关与 Bison 集成并支持 unicode 的另一个词法分析器的建议....
事实证明，在 Flex 中获得 unicode 支持会很痛苦，除非 Flex 源本身添加它。那里似乎有一些针对 unicode 的实验性内容，但从未将其发布到我能找到的版本中。
Ragel doc is insightful, and comes with built in support for Unicode. I've since found this article 给出了如何使 Ragel 和 C++ 更好地配合使用的示例。似乎是更好的选择，所以就这样吧。
希望这可以节省其他人解决这个问题的时间。
编辑
"Built in support" 上面说的可能有点夸张。获得 unicode 支持变得更加容易，但它不仅仅是开箱即用的东西。 我使用 cmake 从派生的 UCD 7 文件生成状态机。 在 CMakeLists.txt 我做：
#Ruby is required to generate a unicode Ragel machine
FIND_PACKAGE(Ruby REQUIRED)
MESSAGE("Found Ruby ${RUBY_VERSION}")
SET(UNICODE_MACHINE_PATH "${PROJECT_SOURCE_DIR}/src/unicode.rl")
if(NOT EXISTS ${UNICODE_MACHINE_PATH} OR gen_unicode)
MESSAGE("Attempting to generate unicode state machine")
EXECUTE_PROCESS(COMMAND ${RUBY_EXECUTABLE} ${PROJECT_SOURCE_DIR}/unicode2ragel.rb
OUTPUT_FILE ${UNICODE_MACHINE_PATH}
RESULT_VARIABLE RAGEL_UNICODE_GEN_RES)
if(${RAGEL_UNICODE_GEN_RES} EQUAL 0)
MESSAGE("Generaged Ragel Unicode state machine")
else()
MESSAGE(SEND_ERROR "Unable to generate unicode state machine")
endif()
endif()
然后在 unicode2ragel.rb（与 Ragel 一起发布并针对 UCD 7 稍作修改）
#!/usr/bin/env ruby
#
# This script uses the unicode spec to generate a Ragel state machine
# that recognizes unicode alphanumeric characters. It generates 5
# character classes: uupper, ulower, ualpha, udigit, and ualnum.
# Currently supported encodings are UTF-8 [default] and UCS-4.
#
# Usage: unicode2ragel.rb [options]
# -e, --encoding [ucs4 | utf8] Data encoding
# -h, --help Show this message
#
# This script was originally written as part of the Ferret search
# engine library.
#
# Author: Rakan El-Khalil <rakan@well.com>
require 'optparse'
require 'open-uri'
ENCODINGS = [ :utf8, :ucs4 ]
ALPHTYPES = { :utf8 => "unsigned char", :ucs4 => "unsigned int" }
CHART_URL = "http://www.unicode.org/Public/7.0.0/ucd/extracted/DerivedGeneralCategory.txt"#"http://www.unicode.org/Public/7.0.0/ucd/DerivedCoreProperties.txt"
###
# Display vars & default option
TOTAL_WIDTH = 80
RANGE_WIDTH = 23
@encoding = :utf8
###
# Option parsing
cli_opts = OptionParser.new do |opts|
opts.on("-e", "--encoding [ucs4 | utf8]", "Data encoding") do |o|
@encoding = o.downcase.to_sym
end
opts.on("-h", "--help", "Show this message") do
puts opts
exit
end
end
cli_opts.parse(ARGV)
unless ENCODINGS.member? @encoding
puts "Invalid encoding: #{@encoding}"
puts cli_opts
exit
end
##
# Downloads the document at url and yields every alpha line's hex
# range and description.
def each_alpha( url, property )
open( url ) do |file|
file.each_line do |line|
next if line =~ /^#/;
next if line !~ /; #{property} #/;
range, description = line.split(/;/)
range.strip!
description.gsub!(/.*#/, '').strip!
if range =~ /\.\./
start, stop = range.split '..'
else start = stop = range
end
yield start.hex .. stop.hex, description
end
end
end
###
# Formats to hex at minimum width
def to_hex( n )
r = "%0X" % n
r = "0#{r}" unless (r.length % 2).zero?
r
end
###
# UCS4 is just a straight hex conversion of the unicode codepoint.
def to_ucs4( range )
rangestr = "0x" + to_hex(range.begin)
rangestr << "..0x" + to_hex(range.end) if range.begin != range.end
[ rangestr ]
end
##
# 0x00 - 0x7f -> 0zzzzzzz[7]
# 0x80 - 0x7ff -> 110yyyyy[5] 10zzzzzz[6]
# 0x800 - 0xffff -> 1110xxxx[4] 10yyyyyy[6] 10zzzzzz[6]
# 0x010000 - 0x10ffff -> 11110www[3] 10xxxxxx[6] 10yyyyyy[6] 10zzzzzz[6]
UTF8_BOUNDARIES = [0x7f, 0x7ff, 0xffff, 0x10ffff]
def to_utf8_enc( n )
r = 0
if n <= 0x7f
r = n
elsif n <= 0x7ff
y = 0xc0 | (n >> 6)
z = 0x80 | (n & 0x3f)
r = y << 8 | z
elsif n <= 0xffff
x = 0xe0 | (n >> 12)
y = 0x80 | (n >> 6) & 0x3f
z = 0x80 | n & 0x3f
r = x << 16 | y << 8 | z
elsif n <= 0x10ffff
w = 0xf0 | (n >> 18)
x = 0x80 | (n >> 12) & 0x3f
y = 0x80 | (n >> 6) & 0x3f
z = 0x80 | n & 0x3f
r = w << 24 | x << 16 | y << 8 | z
end
to_hex(r)
end
def from_utf8_enc( n )
n = n.hex
r = 0
if n <= 0x7f
r = n
elsif n <= 0xdfff
y = (n >> 8) & 0x1f
z = n & 0x3f
r = y << 6 | z
elsif n <= 0xefffff
x = (n >> 16) & 0x0f
y = (n >> 8) & 0x3f
z = n & 0x3f
r = x << 10 | y << 6 | z
elsif n <= 0xf7ffffff
w = (n >> 24) & 0x07
x = (n >> 16) & 0x3f
y = (n >> 8) & 0x3f
z = n & 0x3f
r = w << 18 | x << 12 | y << 6 | z
end
r
end
###
# Given a range, splits it up into ranges that can be continuously
# encoded into utf8. Eg: 0x00 .. 0xff => [0x00..0x7f, 0x80..0xff]
# This is not strictly needed since the current [5.1] unicode standard
# doesn't have ranges that straddle utf8 boundaries. This is included
# for completeness as there is no telling if that will ever change.
def utf8_ranges( range )
ranges = []
UTF8_BOUNDARIES.each do |max|
if range.begin <= max
return ranges << range if range.end <= max
ranges << range.begin .. max
range = (max + 1) .. range.end
end
end
ranges
end
def build_range( start, stop )
size = start.size/2
left = size - 1
return [""] if size < 1
a = start[0..1]
b = stop[0..1]
###
# Shared prefix
if a == b
return build_range(start[2..-1], stop[2..-1]).map do |elt|
"0x#{a} " + elt
end
end
###
# Unshared prefix, end of run
return ["0x#{a}..0x#{b} "] if left.zero?
###
# Unshared prefix, not end of run
# Range can be 0x123456..0x56789A
# Which is equivalent to:
# 0x123456 .. 0x12FFFF
# 0x130000 .. 0x55FFFF
# 0x560000 .. 0x56789A
ret = []
ret << build_range(start, a + "FF" * left)
###
# Only generate middle range if need be.
if a.hex+1 != b.hex
max = to_hex(b.hex - 1)
max = "FF" if b == "FF"
ret << "0x#{to_hex(a.hex+1)}..0x#{max} " + "0x00..0xFF " * left
end
###
# Don't generate last range if it is covered by first range
ret << build_range(b + "00" * left, stop) unless b == "FF"
ret.flatten!
end
def to_utf8( range )
utf8_ranges( range ).map do |r|
build_range to_utf8_enc(r.begin), to_utf8_enc(r.end)
end.flatten!
end
##
# Perform a 3-way comparison of the number of codepoints advertised by
# the unicode spec for the given range, the originally parsed range,
# and the resulting utf8 encoded range.
def count_codepoints( code )
code.split(' ').inject(1) do |acc, elt|
if elt =~ /0x(.+)\.\.0x(.+)/
if @encoding == :utf8
acc * (from_utf8_enc() - from_utf8_enc() + 1)
else
acc * (.hex - .hex + 1)
end
else
acc
end
end
end
def is_valid?( range, desc, codes )
spec_count = 1
spec_count = .to_i if desc =~ /\[(\d+)\]/
range_count = range.end - range.begin + 1
sum = codes.inject(0) { |acc, elt| acc + count_codepoints(elt) }
sum == spec_count and sum == range_count
end
##
# Generate the state maching to stdout
def generate_machine( name, property )
pipe = " "
puts " #{name} = "
each_alpha( CHART_URL, property ) do |range, desc|
codes = (@encoding == :ucs4) ? to_ucs4(range) : to_utf8(range)
raise "Invalid encoding of range #{range}: #{codes.inspect}" unless
is_valid? range, desc, codes
range_width = codes.map { |a| a.size }.max
range_width = RANGE_WIDTH if range_width < RANGE_WIDTH
desc_width = TOTAL_WIDTH - RANGE_WIDTH - 11
desc_width -= (range_width - RANGE_WIDTH) if range_width > RANGE_WIDTH
if desc.size > desc_width
desc = desc[0..desc_width - 4] + "..."
end
codes.each_with_index do |r, idx|
desc = "" unless idx.zero?
code = "%-#{range_width}s" % r
puts " #{pipe} #{code} ##{desc}"
pipe = "|"
end
end
puts " ;"
puts ""
end
puts <<EOF
# The following Ragel file was autogenerated from: #{CHART_URL}
#
# It defines ualpha, udigit, ualnum.
#
# To use this, make sure that your alphtype is set to #{ALPHTYPES[@encoding]},
# and that your input is in #{@encoding}.
%%{
machine WChar;
EOF
generate_machine( :uUppercaseLetter, "Lu" )
generate_machine( :uLowercaseLetter, "Ll" )
generate_machine( :uTitlecaseLetter, "Lt" )
generate_machine( :uModifierLetter, "Lm" )
generate_machine( :uOtherLetter, "Lo" )
generate_machine( :uNonspacingMark, "Mn" )
generate_machine( :uEnclosingMark, "Me" )
generate_machine( :uSpacingMark, "Mc" )
generate_machine( :uDecimalNumber, "Nd" )
generate_machine( :uLetterNumber, "Nl" )
generate_machine( :uOtherNumber, "No" )
generate_machine( :uSpaceSeparator, "Zs" )
generate_machine( :uLineSeparator, "Zl" )
generate_machine( :uParagraphSeparator, "Zp" )
generate_machine( :uFormat, "Cf" )
generate_machine( :uPrivateUse, "Co" )
generate_machine( :uSurrogate, "Cs" )
generate_machine( :uDashPunctuation, "Pd" )
generate_machine( :uOpenPunctuation, "Ps" )
generate_machine( :uClosePunctuation, "Pe" )
generate_machine( :uConnectorPunctuation, "Pc" )
generate_machine( :uOtherPunctuation, "Po" )
generate_machine( :uMathSymbol, "Sm" )
generate_machine( :uCurrencySymbol, "Sc" )
generate_machine( :uModifierSymbol, "Sk" )
generate_machine( :uOtherSymbol, "So" )
generate_machine( :uInitialPunctuation, "Pi" )
generate_machine( :uFinalPunctuation, "Pf" )
puts <<EOF
}%%
EOF
然后在您的 ragel 机器文件中，您可以包含 unicode.rl 并访问定义的每个 unicode 组，例如 uUppercaseLetter 等等...
"Also open to suggestions for another lexer that integrates with Bison and has unicode support...."
RE/flex project 为 C++ 提供了一个兼容 Flex 的词法分析器生成器，它支持 Unicode 并与 Bison 一起工作。
它接受您的示例（稍作修改，以修复语法）：
%option unicode
ascSymbol [!#$%&⋆+./<=>?@\^\-~:]
uniSymbol [\p{Symbol}\p{Other_Symbol}\p{Punctuation}]{-}[\^|_"',;]
symbol {ascSymbol}|{uniSymbol}