Ruby Best Practices

Workarounds for Common Issues

Although we have seen that some functionality is simply not portable between Ruby 1.8 and 1.9, there are many more areas in which Ruby 1.9 just does things a little differently or more conveniently. In these cases, we can develop suitable workarounds that allow our code to run on both versions of Ruby. Let’s take a look at a few of these issues and how we can deal with them.

Using Enumerator

In Ruby 1.9, you can get back an Enumerator for pretty much every method that iterates over a collection:

>> [1,2,3,4].map.with_index { |e,i| e + i }
=> [1, 3, 5, 7]

In Ruby 1.8, Enumerator is part of the standard library instead of core, and isn’t quite as feature-packed. However, we can still accomplish the same goals by being a bit more verbose:

>> require "enumerator"
=> true
>> [1,2,3,4].enum_for(:each_with_index).map { |e,i| e + i }
=> [1, 3, 5, 7]

Because Ruby 1.9’s implementation of Enumerator is mostly backward-compatible with Ruby 1.8, you can write your code in this legacy style without fear of breaking anything.

String Iterators

In Ruby 1.8, Strings are Enumerable, whereas in Ruby 1.9, they are not. Ruby 1.9 provides String#lines, String#each_line, String#each_char, and String#each_byte, all of which are not present in Ruby 1.8.

The best bet here is to backport the features you need to Ruby 1.8, and avoid treating a String as an Enumerable sequence of lines. When you need that functionality, use String#lines followed by whatever enumerable method you need.

The ...