Citation :1.2.2. Syntactic notation

This standard uses the Augmented Backus-Naur Form (ABNF) notation
specified in [RFC2234] for the formal definitions of the syntax of
messages. Characters will be specified either by a decimal value
(e.g., the value %d65 for uppercase A and %d97 for lowercase A) or by
a case-insensitive literal value enclosed in quotation marks (e.g.,
"A" for either uppercase or lowercase A). See [RFC2234] for the full
description of the notation.

# Dans ma classe Account.

before_save :convert_email_to_downcase

def :convert_email_to_downcase

  self.email = email.downcase

end

def email=(input_email)

  # self.email = input_email.downcase <= WRONG

  @email = input_email.downcase

end

class Account < ActiveRecord::Base

  def email=(email)

    self[:email] = email.downcase # ou write_attribute(:email, email.downcase)

  end

end

def email=(input_email)

  @email = input_email.downcase

end

# Example:

if condition

  method1

else

  method2

end

# est pareil que:

condition ? method1 : method2