grammar BasicTypes

  # space really is just space. ruby is newline sensitive, so there is more whitespace footwork
  # rule of thumb is that anything eats space behind it, but only space, no newlines
  rule space  [ \t]*  end

  rule linebreak "\n" end

  rule comment
    "#" (/.*/ !linebreak) linebreak
  end

  rule name_expression
     (name:([a-z_] [a-zA-Z0-9_]*) space?) { Ast::NameExpression.new(capture(:name).to_str)}
  end

  rule digits
    [0-9] [0-9]*
  end

  rule integer_expression
    (digits space?) { Ast::IntegerExpression.new(to_str.to_i) }
  end

  rule instance_variable
    ('@' ivar:name_expression) { Ast::VariableExpression.new (capture(:ivar).value).name }
  end

  rule basic_expression
    name_expression | integer_expression | instance_variable
  end
end