From: "Peña, Botp" <botp@...>
Date: 2007-07-24T14:04:32+09:00
Subject: Re: Is there a replacement for sub?

From: bbiker [mailto:renard3411@gmail.com] 
# str = "hello"
# str.downcase!.capitalize!    =>  NoMethodError: undefined method
# `captitalize!' for nil:NilClass
# 
# My point is that method chaining is a common ruby idiom and nil
# returns get in the way!!!

imnsh opinion, 

bang methods do _not_ look nice on chains. In fact, they look like they cut chains :)

use non-bang methods instead. syntax is very clean.

these are some stupid examples,

irb(main):001:0> "asdf".downcase
=> "asdf"
irb(main):002:0> "asdf".downcase!
=> nil
irb(main):003:0> "asdf".downcase.capitalize.capitalize
=> "Asdf"
irb(main):004:0> "asdf".downcase!
=> nil
irb(main):005:0> "asdf".downcase!.capitalize!
NoMethodError: undefined method `capitalize!' for nil:NilClass
        from (irb):5
        from :0
irb(main):006:0> "asdfX".downcase!.capitalize!
=> "Asdfx"
irb(main):007:0> "asdfX".downcase!.capitalize!.capitalize!
=> nil
irb(main):008:0> "asdfX".downcase!.capitalize!.capitalize!.capitalize!
NoMethodError: undefined method `capitalize!' for nil:NilClass
        from (irb):8
        from :0
irb(main):009:0> "asdfX".downcase.capitalize.capitalize.capitalize
=> "Asdfx"


kind regards -botp