Class: SrcLexer::Lexer::StringIterator

Inherits:
Object
  • Object
show all
Defined in:
lib/src_lexer.rb

Instance Method Summary collapse

Constructor Details

#initialize(str) ⇒ StringIterator

Returns a new instance of StringIterator.



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# File 'lib/src_lexer.rb', line 64

def initialize(str)
  @str = str
  @current_pos = PosInfo.new
  @marked_pos = PosInfo.new
  mark_clear()
end

Instance Method Details

#<(index) ⇒ Object 



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# File 'lib/src_lexer.rb', line 121

def <(index)
  @current_pos.index < index
end

#is(target_string) ⇒ Object 



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# File 'lib/src_lexer.rb', line 81

def is(target_string)
  return false if target_string.length.zero?
  end_pos = (@current_pos.index + target_string.length - 1)
  @str[@current_pos.index..end_pos] == target_string
end

#is_in(target_list) ⇒ Object 



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# File 'lib/src_lexer.rb', line 87

def is_in(target_list)
  target_list.find { |target| is(target) } != nil
end

#is_white_space ⇒ Object 



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# File 'lib/src_lexer.rb', line 125

def is_white_space
  /\s/.match(@str[@current_pos.index])
end

#mark_clear ⇒ Object 



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# File 'lib/src_lexer.rb', line 71

def mark_clear
  @marked_pos.index = -1
  @marked_pos.line_no = 0
  @marked_pos.char_no = 0
end

#mark_set ⇒ Object 



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# File 'lib/src_lexer.rb', line 77

def mark_set
  @marked_pos = @current_pos.clone
end

#marked? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/src_lexer.rb', line 129

def marked?
  @marked_pos.index != -1
end

#move_next ⇒ Object 



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# File 'lib/src_lexer.rb', line 91

def move_next
  if /\n/.match @str[@current_pos.index]
    @current_pos.line_no += 1
    @current_pos.char_no = 1
  else
    @current_pos.char_no += 1
  end
  @current_pos.index += 1
end

#move_to(target) ⇒ Object 



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# File 'lib/src_lexer.rb', line 107

def move_to(target)
  char_count_to_target = (@str[@current_pos.index..-1] =~ /#{Regexp.escape(target)}/m) + target.length - 1
  chopped_string = @str[@current_pos.index..@current_pos.index + char_count_to_target]
  @current_pos.index += char_count_to_target
  match = /.*\n(.*)$/m.match(chopped_string)
  p match[1].length if match
  if match
    @current_pos.char_no = match[1].length
  else
    @current_pos.char_no += char_count_to_target
  end
  @current_pos.line_no += chopped_string.each_char.select{|char| /\n/.match char}.length
end

#move_to_the_end_of_the_line ⇒ Object 



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# File 'lib/src_lexer.rb', line 101

def move_to_the_end_of_the_line
  char_count_to_the_end_of_the_line = (@str[@current_pos.index..-1] =~ /$/) - 1
  @current_pos.index += char_count_to_the_end_of_the_line
  @current_pos.char_no += char_count_to_the_end_of_the_line
end

#shift ⇒ Object 



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# File 'lib/src_lexer.rb', line 133

def shift
  result = [@str[@marked_pos.index..(@current_pos.index - 1)], @marked_pos.line_no, @marked_pos.char_no]
  mark_clear()
  return result
end