class String

Constants

BLANK_RE
ENCODED_BLANKS

Public Instance Methods

at(position) click to toggle source

If you pass a single integer, 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
# File lib/simple_ext/string/access.rb, line 29
def at(position)
  self[position]
end
blank?() click to toggle source

A string is blank if it's empty or contains whitespaces only:

''.blank?       # => true
'   '.blank?    # => true
"\t\n\r".blank? # => true
' blah '.blank? # => false

Unicode whitespace is supported:

"\u00a0".blank? # => true

@return [true, false]

# File lib/simple_ext/object/blank.rb, line 120
def blank?
  # The regexp that matches blank strings is expensive. For the case of empty
  # strings we can speed up this method (~3.5x) with an empty? call. The
  # penalty for the rest of strings is marginal.
  empty? ||
    begin
      BLANK_RE.match?(self)
    rescue Encoding::CompatibilityError
      ENCODED_BLANKS[self.encoding].match?(self)
    end
end
exclude?(string) click to toggle source

The inverse of String#include?. Returns true if the string does not include the other string.

"hello".exclude? "lo" # => false
"hello".exclude? "ol" # => true
"hello".exclude? ?h   # => false
# File lib/simple_ext/string/access.rb, line 102
def exclude?(string)
  !include?(string)
end
first(limit = 1) click to toggle source

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 a copy of self.

str = "hello"
str.first    # => "h"
str.first(1) # => "h"
str.first(2) # => "he"
str.first(0) # => ""
str.first(6) # => "hello"
# File lib/simple_ext/string/access.rb, line 78
def first(limit = 1)
  self[0, limit] || raise(ArgumentError, "negative limit")
end
from(position) click to toggle source

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"
# File lib/simple_ext/string/access.rb, line 46
def from(position)
  self[position, length]
end
last(limit = 1) click to toggle source

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 a copy of self.

str = "hello"
str.last    # => "o"
str.last(1) # => "o"
str.last(2) # => "lo"
str.last(0) # => ""
str.last(6) # => "hello"
# File lib/simple_ext/string/access.rb, line 92
def last(limit = 1)
  self[[length - limit, 0].max, limit] || raise(ArgumentError, "negative limit")
end
remove(*patterns) click to toggle source

Returns a new string with all occurrences of the patterns removed.

str = "foo bar test"
str.remove(" test")                 # => "foo bar"
str.remove(" test", /bar/)          # => "foo "
str                                 # => "foo bar test"
# File lib/simple_ext/string/filters.rb, line 32
def remove(*patterns)
  dup.remove!(*patterns)
end
remove!(*patterns) click to toggle source

Alters the string by removing all occurrences of the patterns.

str = "foo bar test"
str.remove!(" test", /bar/)         # => "foo "
str                                 # => "foo "
# File lib/simple_ext/string/filters.rb, line 40
def remove!(*patterns)
  patterns.each do |pattern|
    gsub! pattern, ""
  end

  self
end
squish() click to toggle source

Returns the string, first removing all whitespace on both ends of the string, and then changing remaining consecutive whitespace groups into one space each.

Note that it handles both ASCII and Unicode whitespace.

%{ Multi-line
   string }.squish                   # => "Multi-line string"
" foo   bar    \n   \t   boo".squish # => "foo bar boo"
# File lib/simple_ext/string/filters.rb, line 13
def squish
  dup.squish!
end
squish!() click to toggle source

Performs a destructive squish. See String#squish.

str = " foo   bar    \n   \t   boo"
str.squish!                         # => "foo bar boo"
str                                 # => "foo bar boo"
# File lib/simple_ext/string/filters.rb, line 21
def squish!
  gsub!(/[[:space:]]+/, " ")
  strip!
  self
end
to(position) click to toggle source

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"
# File lib/simple_ext/string/access.rb, line 63
def to(position)
  position += size if position < 0
  self[0, position + 1] || +""
end
truncate(truncate_at, options = {}) click to toggle source

Truncates a given text after a given length if text is longer than length:

'Once upon a time in a world far far away'.truncate(27)
# => "Once upon a time in a wo..."

Pass a string or regexp :separator to truncate text at a natural break:

'Once upon a time in a world far far away'.truncate(27, separator: ' ')
# => "Once upon a time in a..."

'Once upon a time in a world far far away'.truncate(27, separator: /\s/)
# => "Once upon a time in a..."

The last characters will be replaced with the :omission string (defaults to “…”) for a total length not exceeding length:

'And they found that many people were sleeping better.'.truncate(25, omission: '... (continued)')
# => "And they f... (continued)"
# File lib/simple_ext/string/filters.rb, line 66
def truncate(truncate_at, options = {})
  return dup unless length > truncate_at

  omission = options[:omission] || "..."
  length_with_room_for_omission = truncate_at - omission.length
  stop = \
    if options[:separator]
      rindex(options[:separator], length_with_room_for_omission) || length_with_room_for_omission
    else
      length_with_room_for_omission
    end

  +"#{self[0, stop]}#{omission}"
end
truncate_bytes(truncate_at, omission: "…") click to toggle source

Truncates text to at most bytesize bytes in length without breaking string encoding by splitting multibyte characters or breaking grapheme clusters (“perceptual characters”) by truncating at combining characters.

>> "🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪".size
=> 20
>> "🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪".bytesize
=> 80
>> "🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪🔪".truncate_bytes(20)
=> "🔪🔪🔪🔪…"

The truncated text ends with the :omission string, defaulting to “…”, for a total length not exceeding bytesize.

# File lib/simple_ext/string/filters.rb, line 95
def truncate_bytes(truncate_at, omission: "…")
  omission ||= ""

  case
  when bytesize <= truncate_at
    dup
  when omission.bytesize > truncate_at
    raise ArgumentError, "Omission #{omission.inspect} is #{omission.bytesize}, larger than the truncation length of #{truncate_at} bytes"
  when omission.bytesize == truncate_at
    omission.dup
  else
    self.class.new.tap do |cut|
      cut_at = truncate_at - omission.bytesize

      scan(/\X/) do |grapheme|
        if cut.bytesize + grapheme.bytesize <= cut_at
          cut << grapheme
        else
          break
        end
      end

      cut << omission
    end
  end
end
truncate_words(words_count, options = {}) click to toggle source

Truncates a given text after a given number of words (words_count):

'Once upon a time in a world far far away'.truncate_words(4)
# => "Once upon a time..."

Pass a string or regexp :separator to specify a different separator of words:

'Once<br>upon<br>a<br>time<br>in<br>a<br>world'.truncate_words(5, separator: '<br>')
# => "Once<br>upon<br>a<br>time<br>in..."

The last characters will be replaced with the :omission string (defaults to “…”):

'And they found that many people were sleeping better.'.truncate_words(5, omission: '... (continued)')
# => "And they found that many... (continued)"
# File lib/simple_ext/string/filters.rb, line 136
def truncate_words(words_count, options = {})
  sep = options[:separator] || /\s+/
  sep = Regexp.escape(sep.to_s) unless Regexp === sep
  if self =~ /\A((?>.+?#{sep}){#{words_count - 1}}.+?)#{sep}.*/m
    $1 + (options[:omission] || "...")
  else
    dup
  end
end