ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.12/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             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