Class: RegexpExamples::CharGroup

Inherits:
Object
  • Object
show all
Defined in:
lib/regexp-examples/groups.rb

Instance Method Summary collapse

Constructor Details

#initialize(chars) ⇒ CharGroup

Returns a new instance of CharGroup.



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# File 'lib/regexp-examples/groups.rb', line 31

def initialize(chars)
  @chars = chars
  if chars[0] == "^"
    @negative = true
    @chars = @chars[1..-1]
  else
    @negative = false
  end

  init_backslash_chars
  init_ranges
end

Instance Method Details

#init_backslash_chars ⇒ Object 



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# File 'lib/regexp-examples/groups.rb', line 66

def init_backslash_chars
  @chars.each_with_index do |char, i|
    if char == "\\"
      if BackslashCharMap.keys.include?(@chars[i+1])
        @chars[i..i+1] = move_backslash_to_front( BackslashCharMap[@chars[i+1]] )
      elsif @chars[i+1] == 'b'
        @chars[i..i+1] = "\b"
      elsif @chars[i+1] == "\\"
        @chars.delete_at(i+1)
      else
        @chars.delete_at(i)
      end
    end
  end
end

#init_ranges ⇒ Object 



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# File 'lib/regexp-examples/groups.rb', line 44

def init_ranges
  # save first and last "-" if present
  first = nil
  last = nil
  first = @chars.shift if @chars.first == "-"
  last = @chars.pop if @chars.last == "-"
  # Replace all instances of e.g. ["a", "-", "z"] with ["a", "b", ..., "z"]
  while i = @chars.index("-")
    # Prevent infinite loops from expanding [",", "-", "."] to itself
    # (Since ",".ord = 44, "-".ord = 45, ".".ord = 46)
    if (@chars[i-1] == ',' && @chars[i+1] == '.')
      first = '-'
      @chars.delete_at(i)
    else
      @chars[i-1..i+1] = (@chars[i-1]..@chars[i+1]).to_a
    end
  end
  # restore them back
  @chars.unshift(first) if first
  @chars.push(last) if last
end

#result ⇒ Object 



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# File 'lib/regexp-examples/groups.rb', line 82

def result
  (@negative ? (CharSets::Any - @chars) : @chars).map do |result|
    GroupResult.new(result)
  end
end