Module: KPeg::Position

Included in:
CompiledParser, Parser
Defined in:
lib/kpeg/position.rb

Defined Under Namespace

Classes: KpegPosInfo

Instance Method Summary collapse

Instance Method Details

#current_character(target = pos) ⇒ Object 



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# File 'lib/kpeg/position.rb', line 44

def current_character(target=pos)
  if target < 0 || target >= string.size
    raise "Target position #{target} is outside of string"
  end
  string[target, 1]
end

#current_column(target = pos) ⇒ Object

STANDALONE START



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# File 'lib/kpeg/position.rb', line 5

def current_column(target=pos)
  if string[target] == "\n" && (c = string.rindex("\n", target-1) || -1)
    return target - c
  elsif c = string.rindex("\n", target)
    return target - c
  end

  target + 1
end

#current_line(target = pos) ⇒ Object 



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# File 'lib/kpeg/position.rb', line 28

def current_line(target=pos)
  if line = position_line_offsets.bsearch_index {|x| x > target }
    return line + 1
  end
  raise "Target position #{target} is outside of string"
end

#current_pos_info(target = pos) ⇒ Object 



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# File 'lib/kpeg/position.rb', line 53

def current_pos_info(target=pos)
  l = current_line target
  c = current_column target
  ln = get_line(l-1)
  chr = string[target,1]
  KpegPosInfo.new(target, l, c, ln, chr)
end

#get_line(no) ⇒ Object 



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# File 'lib/kpeg/position.rb', line 65

def get_line(no)
  loff = position_line_offsets
  if no < 0
    raise "Line No is out of range: #{no} < 0"
  elsif no >= loff.size
    raise "Line No is out of range: #{no} >= #{loff.size}"
  end
  lend = loff[no]-1
  lstart = no > 0 ? loff[no-1] : 0
  string[lstart..lend]
end

#lines ⇒ Object 



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# File 'lib/kpeg/position.rb', line 61

def lines
  string.lines
end

#position_line_offsets ⇒ Object 



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# File 'lib/kpeg/position.rb', line 15

def position_line_offsets
  unless @position_line_offsets
    @position_line_offsets = []
    total = 0
    string.each_line do |line|
      total += line.size
      @position_line_offsets << total
    end
  end
  @position_line_offsets
end