ruby - 如何写一个复杂的条件

Question

当您有一个简单的条件和一个可能复杂的主体时，条件构造很容易编写:

if simple_condition_expressed_in_one_liner
  complicated_body_that_may_be_long
  complicated_body_that_may_be_long
  complicated_body_that_may_be_long
end

但有时候，你的情况很复杂， body 很简单，就像这样:

if condition1 and
condition2 and
condition3 and
some_more_complicated_condition_that_cannot_be_written_on_a_single_line and
still_some_more_complicated_condition_that_cannot_be_written_on_a_single_line
  simple_body
end

这样的话，有什么好的写法吗？

Answer 1

我总是尝试重构为更小的描述方法。

使用您的示例，而不是:

until (print "Username : "; gets.chomp == "user") and
      (print "Password : "; gets.chomp == "pa$$word")
  puts "Error, incorrect details"
end

我会使用:

def correct_user
  print "Username : "
  gets.chomp == "user"
end

def correct_password
  print "Password : "
  gets.chomp == "pa$$word"
end

until correct_user and correct_password
  puts "Error, incorrect details"
end