Move Unit stuff from Imbecile::Regex to Imbecile::Regex::Unit
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@ -1,6 +1,7 @@
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require_relative "imbecile/cli"
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require_relative "imbecile/grammar"
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require_relative "imbecile/regex"
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require_relative "imbecile/regex/unit"
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require_relative "imbecile/version"
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require "erb"
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@ -14,204 +14,7 @@ module Imbecile
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end
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def initialize(pattern)
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@pattern = pattern.dup
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parse
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end
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private
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class Unit
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end
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class SequenceUnit < Unit
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attr_accessor :units
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def initialize
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@units = []
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end
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def method_missing(*args)
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@units.__send__(*args)
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end
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end
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class AlternatesUnit < Unit
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attr_accessor :alternates
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attr_accessor :negate
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def initialize
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@alternates = []
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@negate = false
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end
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def new_alternate!
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@alternates << SequenceUnit.new
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end
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def append_alternate(unit)
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@alternates << unit
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end
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def <<(unit)
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new_alternate! if @alternates.empty?
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@alternates[-1] << unit
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end
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def last_unit
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new_alternate! if @alternates.empty?
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@alternates[-1][-1]
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end
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def replace_last!(new_unit)
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@alternates[-1][-1] = new_unit
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end
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end
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class CharacterUnit < Unit
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attr_accessor :code_point
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def initialize(c)
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@code_point = c.ord
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end
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end
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class CharacterRangeUnit < Unit
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attr_accessor :start_code_point
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attr_accessor :end_code_point
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def initialize(c1, c2)
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@start_code_point = c1.ord
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@end_code_point = c2.ord
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end
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end
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class MultiplicityUnit < Unit
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attr_accessor :unit
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attr_accessor :min_count
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attr_accessor :max_count
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def initialize(unit, min_count, max_count)
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@unit = unit
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@min_count = min_count
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@max_count = max_count
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end
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end
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def parse
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@unit = parse_alternates
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if @pattern != ""
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raise "Invalid pattern: #{@pattern}"
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end
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end
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def parse_alternates
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au = AlternatesUnit.new
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while @pattern != ""
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c = @pattern[0]
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return au if c == ")"
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@pattern.slice!(0)
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case c
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when "["
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au << parse_character_class
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when "("
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au << parse_group
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when "*", "+", "?", "{"
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if last_unit = au.last_unit
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case c
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when "*"
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min_count, max_count = 0, nil
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when "+"
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min_count, max_count = 1, nil
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when "?"
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min_count, max_count = 0, 1
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when "{"
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min_count, max_count = parse_curly_count
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end
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mu = MultiplicityUnit.new(last_unit, min_count, max_count)
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au.replace_last!(mu)
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else
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raise Error.new("#{c} follows nothing")
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end
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when "|"
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au.new_alternate!
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when "\\"
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au << parse_backslash
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else
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au << CharacterUnit.new(c)
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end
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end
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au
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end
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def parse_group
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au = parse_alternates
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if @pattern[0] != ")"
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raise Error.new("Unterminated group in pattern")
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end
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@pattern.slice!(0)
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au
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end
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def parse_character_class
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au = AlternatesUnit.new
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index = 0
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loop do
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if @pattern == ""
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raise Error.new("Unterminated character class")
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end
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c = @pattern.slice!(0)
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if c == "]"
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break
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elsif c == "^" && index == 0
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au.negate = true
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elsif c == "-" && (index == 0 || @pattern[0] == "]")
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au.append_alternate(CharacterUnit.new(c))
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elsif c == "\\"
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au.append_alternate(parse_backslash)
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elsif c == "-" && @pattern[0] != "]"
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begin_cu = au.last_unit
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unless begin_cu.is_a?(CharacterUnit)
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raise Error.new("Character range must be between single characters")
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end
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if @pattern[0] == "\\"
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@pattern.slice!(0)
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end_cu = parse_backslash
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unless end_cu.is_a?(CharacterUnit)
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raise Error.new("Character range must be between single characters")
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end
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end_code_point = end_cu.code_point
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else
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end_code_point = @pattern[0].ord
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@pattern.slice!(0)
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end
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cru = CharacterRangeUnit.new(begin_cu.code_point, end_code_point)
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au.replace_last!(cru)
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else
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au.append_alternate(CharacterUnit.new(c))
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end
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index += 1
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end
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au
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end
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def parse_curly_count
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if @pattern =~ /^(\d+)(?:,(\d+))?\}(.*)$/
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min_count = $1.to_i
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max_count = nil
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if $2 != ""
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max_count = $2.to_i
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if max_count < min_count
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raise Error.new("Maximum repetition count cannot be less than minimum repetition count")
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end
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end
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@pattern = $3
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[min_count, max_count]
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else
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raise Error.new("Unexpected match count at #{@pattern}")
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end
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end
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def parse_backslash
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if @pattern == ""
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raise Error.new("Error: unfollowed \\")
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else
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c = @pattern.slice!(0)
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case c
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when "d"
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CharacterRangeUnit.new("0", "9")
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else
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CharacterUnit.new(c)
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end
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end
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@unit = Unit.new(pattern)
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end
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end
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203
lib/imbecile/regex/unit.rb
Normal file
203
lib/imbecile/regex/unit.rb
Normal file
@ -0,0 +1,203 @@
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module Imbecile
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class Regex
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class Unit
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class SequenceUnit < Unit
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attr_accessor :units
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def initialize
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@units = []
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end
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def method_missing(*args)
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@units.__send__(*args)
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end
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end
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class AlternatesUnit < Unit
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attr_accessor :alternates
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attr_accessor :negate
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def initialize
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@alternates = []
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@negate = false
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end
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def new_alternate!
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@alternates << SequenceUnit.new
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end
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def append_alternate(unit)
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@alternates << unit
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end
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def <<(unit)
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new_alternate! if @alternates.empty?
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@alternates[-1] << unit
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end
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def last_unit
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new_alternate! if @alternates.empty?
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@alternates[-1][-1]
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end
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def replace_last!(new_unit)
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@alternates[-1][-1] = new_unit
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end
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end
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class CharacterUnit < Unit
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attr_accessor :code_point
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def initialize(c)
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@code_point = c.ord
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end
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end
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class CharacterRangeUnit < Unit
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attr_accessor :start_code_point
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attr_accessor :end_code_point
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def initialize(c1, c2)
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@start_code_point = c1.ord
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@end_code_point = c2.ord
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end
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end
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class MultiplicityUnit < Unit
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attr_accessor :unit
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attr_accessor :min_count
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attr_accessor :max_count
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def initialize(unit, min_count, max_count)
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@unit = unit
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@min_count = min_count
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@max_count = max_count
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end
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end
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def initialize(pattern)
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@pattern = pattern.dup
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@unit = parse_alternates
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if @pattern != ""
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raise "Invalid pattern: #{@pattern}"
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end
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end
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private
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def parse_alternates
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au = AlternatesUnit.new
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while @pattern != ""
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c = @pattern[0]
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return au if c == ")"
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@pattern.slice!(0)
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case c
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when "["
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au << parse_character_class
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when "("
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au << parse_group
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when "*", "+", "?", "{"
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if last_unit = au.last_unit
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case c
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when "*"
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min_count, max_count = 0, nil
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when "+"
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min_count, max_count = 1, nil
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when "?"
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min_count, max_count = 0, 1
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when "{"
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min_count, max_count = parse_curly_count
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end
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mu = MultiplicityUnit.new(last_unit, min_count, max_count)
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au.replace_last!(mu)
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else
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raise Error.new("#{c} follows nothing")
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end
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when "|"
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au.new_alternate!
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when "\\"
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au << parse_backslash
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else
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au << CharacterUnit.new(c)
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end
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end
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au
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end
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def parse_group
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au = parse_alternates
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if @pattern[0] != ")"
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raise Error.new("Unterminated group in pattern")
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end
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@pattern.slice!(0)
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au
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end
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def parse_character_class
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au = AlternatesUnit.new
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index = 0
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loop do
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if @pattern == ""
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raise Error.new("Unterminated character class")
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end
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c = @pattern.slice!(0)
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if c == "]"
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break
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elsif c == "^" && index == 0
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au.negate = true
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elsif c == "-" && (index == 0 || @pattern[0] == "]")
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au.append_alternate(CharacterUnit.new(c))
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elsif c == "\\"
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au.append_alternate(parse_backslash)
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elsif c == "-" && @pattern[0] != "]"
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begin_cu = au.last_unit
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unless begin_cu.is_a?(CharacterUnit)
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raise Error.new("Character range must be between single characters")
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end
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if @pattern[0] == "\\"
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@pattern.slice!(0)
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end_cu = parse_backslash
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unless end_cu.is_a?(CharacterUnit)
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raise Error.new("Character range must be between single characters")
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end
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end_code_point = end_cu.code_point
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else
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end_code_point = @pattern[0].ord
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@pattern.slice!(0)
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end
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cru = CharacterRangeUnit.new(begin_cu.code_point, end_code_point)
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au.replace_last!(cru)
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else
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au.append_alternate(CharacterUnit.new(c))
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end
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index += 1
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end
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au
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end
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def parse_curly_count
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if @pattern =~ /^(\d+)(?:,(\d+))?\}(.*)$/
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min_count = $1.to_i
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max_count = nil
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if $2 != ""
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max_count = $2.to_i
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if max_count < min_count
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raise Error.new("Maximum repetition count cannot be less than minimum repetition count")
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end
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end
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@pattern = $3
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[min_count, max_count]
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else
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raise Error.new("Unexpected match count at #{@pattern}")
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end
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end
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def parse_backslash
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if @pattern == ""
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raise Error.new("Error: unfollowed \\")
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else
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c = @pattern.slice!(0)
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case c
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when "d"
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CharacterRangeUnit.new("0", "9")
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else
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CharacterUnit.new(c)
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end
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end
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end
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end
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end
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end
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