为什么relative_require不能在Ruby 1.8.6上运行？

Question

我在Windows 7上学习Ruby(使用版本1.8.6).

当我尝试运行下面的stock_stats.rb程序时,我收到以下错误:

C:\Users\Will\Desktop\ruby>ruby stock_stats.rb
stock_stats.rb:1: undefined method `require_relative' for main:Object (NoMethodE
rror)

我有三个v.small代码文件:

stock_stats.rb

require_relative 'csv_reader'

reader = CsvReader.new

ARGV.each do |csv_file_name|
  STDERR.puts "Processing #{csv_file_name}"
  reader.read_in_csv_data(csv_file_name)
end

puts "Total value = #{reader.total_value_in_stock}"

csv_reader.rb

require 'csv' 
require_relative 'book_in_stock'

class CsvReader

  def initialize
    @books_in_stock = []
  end

  def read_in_csv_data(csv_file_name)
    CSV.foreach(csv_file_name, headers: true) do |row|
      @books_in_stock << BookInStock.new(row["ISBN"], row["Amount"])
    end
  end  

  # later we'll see how to use inject to sum a collection
  def total_value_in_stock
    sum = 0.0        
    @books_in_stock.each {|book| sum += book.price}
    sum
  end  

  def number_of_each_isbn
    # ...
  end

end       

book_in_stock.rb

require 'csv' 
require_relative 'book_in_stock'

class CsvReader

  def initialize
    @books_in_stock = []
  end

  def read_in_csv_data(csv_file_name)
    CSV.foreach(csv_file_name, headers: true) do |row|
      @books_in_stock << BookInStock.new(row["ISBN"], row["Amount"])
    end
  end  

  # later we'll see how to use inject to sum a collection
  def total_value_in_stock
    sum = 0.0        
    @books_in_stock.each {|book| sum += book.price}
    sum
  end  

  def number_of_each_isbn
    # ...
  end

end       

在此先感谢您的帮助.

Answer 1

require_relative在您的Ruby版本中不存在.您可以升级Ruby,安装backports gem,require 'backports/1.9.1/kernel/require/relative'但最简单的修复方法是将您的需求更改为:

require File.join(File.dirname(__FILE__), 'csv_reader')

Answer 2

编辑:

回到问这个问题的日子里,它提到了Ruby 1.8.6,其中没有require_relative.到目前为止,Ruby 1.8.6已经过时,不应该再使用了.

原版的:

根本没有方法名称require_relative.你也可以require在那里使用.

该require_relative函数包含在Ruby核心库的扩展项目中,可在此处找到:http://www.rubyforge.org/projects/extensions

你应该能够安装它们gem install extensions.然后在您的代码中添加以下行require_relative:

require 'extensions/all'