lib/monkey/lexer.rb
def peek_char
      if @read_position >= @input.length
        "\x0"
      else
        @input[@read_position]
      end
    end
# Initialize the lexer with the given input.
#
# @param input [String] the text that will be lexed
Initialize the lexer with the given input.
Initialize the lexer with the given input .
def peek_char
      if @read_position >= @input.length
        "\x0"
      else
        @input[@read_position]
      end
    end
def peek_char if @read_position >= @input . length "\x0" else @input [ @read_position ] end end
Initialize the lexer with the given input.
Initialize the lexer with the given input .
input
the text that will be lexed
the text that will be lexed