vendor/rails/activesupport/lib/active_support/core_ext/string/access.rb

   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             mb_chars[0..(limit - 1)].to_s
  45           end
  46
  47           # Returns the last character of the string or the last +limit+ characters.
  48           #
  49           # Examples:
  50           #   "hello".last     # => "o"
  51           #   "hello".last(2)  # => "lo"
  52           #   "hello".last(10) # => "hello"
  53           def last(limit = 1)
  54             (mb_chars[(-limit)..-1] || self).to_s
  55           end
  56         end
  57       else
  58         module Access #:nodoc:
  59           def at(position)
  60             self[position]
  61           end
  62
  63           def from(position)
  64             self[position..-1]
  65           end
  66
  67           def to(position)
  68             self[0..position]
  69           end
  70
  71           def first(limit = 1)
  72             self[0..(limit - 1)]
  73           end
  74
  75           def last(limit = 1)
  76             from(-limit) || self
  77           end
  78         end
  79       end
  80     end
  81   end
  82 end