diff options
Diffstat (limited to 'activesupport/lib/active_support/core_ext/string/access.rb')
| -rw-r--r-- | activesupport/lib/active_support/core_ext/string/access.rb | 185 |
1 files changed, 96 insertions, 89 deletions
diff --git a/activesupport/lib/active_support/core_ext/string/access.rb b/activesupport/lib/active_support/core_ext/string/access.rb index c0d5cdf2d5..5c32a2453d 100644 --- a/activesupport/lib/active_support/core_ext/string/access.rb +++ b/activesupport/lib/active_support/core_ext/string/access.rb @@ -1,99 +1,106 @@ -require "active_support/multibyte" +require 'active_support/multibyte' class String - unless '1.9'.respond_to?(:force_encoding) - # Returns the character at the +position+ treating the string as an array (where 0 is the first character). - # - # Examples: - # "hello".at(0) # => "h" - # "hello".at(4) # => "o" - # "hello".at(10) # => ERROR if < 1.9, nil in 1.9 - def at(position) - mb_chars[position, 1].to_s - end - - # Returns the remaining of the string from the +position+ treating the string as an array (where 0 is the first character). - # - # Examples: - # "hello".from(0) # => "hello" - # "hello".from(2) # => "llo" - # "hello".from(10) # => "" if < 1.9, nil in 1.9 - def from(position) - mb_chars[position..-1].to_s - end - - # Returns the beginning of the string up to the +position+ treating the string as an array (where 0 is the first character). - # - # Examples: - # "hello".to(0) # => "h" - # "hello".to(2) # => "hel" - # "hello".to(10) # => "hello" - def to(position) - mb_chars[0..position].to_s - end - - # Returns the first character of the string or the first +limit+ characters. - # - # Examples: - # "hello".first # => "h" - # "hello".first(2) # => "he" - # "hello".first(10) # => "hello" - def first(limit = 1) - if limit == 0 - '' - elsif limit >= size - self - else - mb_chars[0...limit].to_s - end - end - - # Returns the last character of the string or the last +limit+ characters. - # - # Examples: - # "hello".last # => "o" - # "hello".last(2) # => "lo" - # "hello".last(10) # => "hello" - def last(limit = 1) - if limit == 0 - '' - elsif limit >= size - self - else - mb_chars[(-limit)..-1].to_s - end - end - else - def at(position) - self[position] - end + # If you pass a single Fixnum, returns a substring of one character at that + # position. The first character of the string is at position 0, the next at + # position 1, and so on. If a range is supplied, a substring containing + # characters at offsets given by the range is returned. In both cases, if an + # offset is negative, it is counted from the end of the string. Returns nil + # if the initial offset falls outside the string. Returns an empty string if + # the beginning of the range is greater than the end of the string. + # + # str = "hello" + # str.at(0) #=> "h" + # str.at(1..3) #=> "ell" + # str.at(-2) #=> "l" + # str.at(-2..-1) #=> "lo" + # str.at(5) #=> nil + # str.at(5..-1) #=> "" + # + # If a Regexp is given, the matching portion of the string is returned. + # If a String is given, that given string is returned if it occurs in + # the string. In both cases, nil is returned if there is no match. + # + # str = "hello" + # str.at(/lo/) #=> "lo" + # str.at(/ol/) #=> nil + # str.at("lo") #=> "lo" + # str.at("ol") #=> nil + def at(position) + self[position] + end - def from(position) - self[position..-1] - end + # Returns a substring from the given position to the end of the string. + # If the position is negative, it is counted from the end of the string. + # + # str = "hello" + # str.from(0) #=> "hello" + # str.from(3) #=> "lo" + # str.from(-2) #=> "lo" + # + # You can mix it with +to+ method and do fun things like: + # + # str = "hello" + # str.from(0).to(-1) #=> "hello" + # str.from(1).to(-2) #=> "ell" + def from(position) + self[position..-1] + end - def to(position) - self[0..position] - end + # Returns a substring from the beginning of the string to the given position. + # If the position is negative, it is counted from the end of the string. + # + # str = "hello" + # str.to(0) #=> "h" + # str.to(3) #=> "hell" + # str.to(-2) #=> "hell" + # + # You can mix it with +from+ method and do fun things like: + # + # str = "hello" + # str.from(0).to(-1) #=> "hello" + # str.from(1).to(-2) #=> "ell" + def to(position) + self[0..position] + end - def first(limit = 1) - if limit == 0 - '' - elsif limit >= size - self - else - to(limit - 1) - end + # Returns the first character. If a limit is supplied, returns a substring + # from the beginning of the string until it reaches the limit value. If the + # given limit is greater than or equal to the string length, returns self. + # + # str = "hello" + # str.first #=> "h" + # str.first(1) #=> "h" + # str.first(2) #=> "he" + # str.first(0) #=> "" + # str.first(6) #=> "hello" + def first(limit = 1) + if limit == 0 + '' + elsif limit >= size + self + else + to(limit - 1) end + end - def last(limit = 1) - if limit == 0 - '' - elsif limit >= size - self - else - from(-limit) - end + # Returns the last character of the string. If a limit is supplied, returns a substring + # from the end of the string until it reaches the limit value (counting backwards). If + # the given limit is greater than or equal to the string length, returns self. + # + # str = "hello" + # str.last #=> "o" + # str.last(1) #=> "o" + # str.last(2) #=> "lo" + # str.last(0) #=> "" + # str.last(6) #=> "hello" + def last(limit = 1) + if limit == 0 + '' + elsif limit >= size + self + else + from(-limit) end end end |