Specifies a new singularization rule and its replacement. The rule can either be a string or a regular expression. The replacement should always be a string that may include references to the matched data from the rule.
# File activesupport/lib/active_support/inflector/inflections.rb, line 90 def singular(rule, replacement) @uncountables.delete(rule) if rule.is_a?(String) @uncountables.delete(replacement) @singulars.insert(0, [rule, replacement]) end