1  module ActiveSupport #:nodoc:
   2    module CoreExtensions #:nodoc:
   3      module String #:nodoc:
   4        unless '1.9'.respond_to?(:force_encoding)
   5          # Makes it easier to access parts of a string, such as specific characters and substrings.
   6          module Access
   7            # Returns the character at the +position+ treating the string as an array (where 0 is the first character).
   8            #
   9            # Examples: 
  10            #   "hello".at(0)  # => "h"
  11            #   "hello".at(4)  # => "o"
  12            #   "hello".at(10) # => nil
  13            def at(position)
  14              mb_chars[position, 1].to_s
  15            end
  16            
  17            # Returns the remaining of the string from the +position+ treating the string as an array (where 0 is the first character).
  18            #
  19            # Examples: 
  20            #   "hello".from(0)  # => "hello"
  21            #   "hello".from(2)  # => "llo"
  22            #   "hello".from(10) # => nil
  23            def from(position)
  24              mb_chars[position..-1].to_s
  25            end
  26            
  27            # Returns the beginning of the string up to the +position+ treating the string as an array (where 0 is the first character).
  28            #
  29            # Examples: 
  30            #   "hello".to(0)  # => "h"
  31            #   "hello".to(2)  # => "hel"
  32            #   "hello".to(10) # => "hello"
  33            def to(position)
  34              mb_chars[0..position].to_s
  35            end
  36 
  37            # Returns the first character of the string or the first +limit+ characters.
  38            #
  39            # Examples: 
  40            #   "hello".first     # => "h"
  41            #   "hello".first(2)  # => "he"
  42            #   "hello".first(10) # => "hello"
  43            def first(limit = 1)
  44              if limit == 0
  45                ''
  46              elsif limit >= size
  47                self
  48              else
  49                mb_chars[0...limit].to_s
  50              end
  51            end
  52 
  53            # Returns the last character of the string or the last +limit+ characters.
  54            #
  55            # Examples: 
  56            #   "hello".last     # => "o"
  57            #   "hello".last(2)  # => "lo"
  58            #   "hello".last(10) # => "hello"
  59            def last(limit = 1)
  60              if limit == 0
  61                ''
  62              elsif limit >= size
  63                self
  64              else
  65                mb_chars[(-limit)..-1].to_s
  66              end
  67            end
  68          end
  69        else
  70          module Access #:nodoc:
  71            def at(position)
  72              self[position]
  73            end
  74 
  75            def from(position)
  76              self[position..-1]
  77            end
  78 
  79            def to(position)
  80              self[0..position]
  81            end
  82 
  83            def first(limit = 1)
  84              if limit == 0
  85                ''
  86              elsif limit >= size
  87                self
  88              else
  89                to(limit - 1)
  90              end
  91            end
  92 
  93            def last(limit = 1)
  94              if limit == 0
  95                ''
  96              elsif limit >= size
  97                self
  98              else
  99                from(-limit)
 100              end
 101            end
 102          end
 103        end
 104      end
 105    end
 106  end