1class String
2
3  ##
4  # call-seq:
5  #    string.clear    ->  string
6  #
7  # Makes string empty.
8  #
9  #    a = "abcde"
10  #    a.clear    #=> ""
11  #
12  def clear
13    self.replace("")
14  end
15
16  ##
17  # call-seq:
18  #    str.lstrip   -> new_str
19  #
20  # Returns a copy of <i>str</i> with leading whitespace removed. See also
21  # <code>String#rstrip</code> and <code>String#strip</code>.
22  #
23  #    "  hello  ".lstrip   #=> "hello  "
24  #    "hello".lstrip       #=> "hello"
25  #
26  def lstrip
27    a = 0
28    z = self.size - 1
29    a += 1 while a <= z and " \f\n\r\t\v".include?(self[a])
30    (z >= 0) ? self[a..z] : ""
31  end
32
33  ##
34  # call-seq:
35  #    str.rstrip   -> new_str
36  #
37  # Returns a copy of <i>str</i> with trailing whitespace removed. See also
38  # <code>String#lstrip</code> and <code>String#strip</code>.
39  #
40  #    "  hello  ".rstrip   #=> "  hello"
41  #    "hello".rstrip       #=> "hello"
42  #
43  def rstrip
44    a = 0
45    z = self.size - 1
46    z -= 1 while a <= z and " \f\n\r\t\v\0".include?(self[z])
47    (z >= 0) ? self[a..z] : ""
48  end
49
50  ##
51  # call-seq:
52  #    str.strip   -> new_str
53  #
54  # Returns a copy of <i>str</i> with leading and trailing whitespace removed.
55  #
56  #    "    hello    ".strip   #=> "hello"
57  #    "\tgoodbye\r\n".strip   #=> "goodbye"
58  #
59  def strip
60    a = 0
61    z = self.size - 1
62    a += 1 while a <= z and " \f\n\r\t\v".include?(self[a])
63    z -= 1 while a <= z and " \f\n\r\t\v\0".include?(self[z])
64    (z >= 0) ? self[a..z] : ""
65  end
66
67  ##
68  # call-seq:
69  #    str.lstrip!   -> self or nil
70  #
71  # Removes leading whitespace from <i>str</i>, returning <code>nil</code> if no
72  # change was made. See also <code>String#rstrip!</code> and
73  # <code>String#strip!</code>.
74  #
75  #    "  hello  ".lstrip   #=> "hello  "
76  #    "hello".lstrip!      #=> nil
77  #
78  def lstrip!
79    raise FrozenError, "can't modify frozen String" if frozen?
80    s = self.lstrip
81    (s == self) ? nil : self.replace(s)
82  end
83
84  ##
85  # call-seq:
86  #    str.rstrip!   -> self or nil
87  #
88  # Removes trailing whitespace from <i>str</i>, returning <code>nil</code> if
89  # no change was made. See also <code>String#lstrip!</code> and
90  # <code>String#strip!</code>.
91  #
92  #    "  hello  ".rstrip   #=> "  hello"
93  #    "hello".rstrip!      #=> nil
94  #
95  def rstrip!
96    raise FrozenError, "can't modify frozen String" if frozen?
97    s = self.rstrip
98    (s == self) ? nil : self.replace(s)
99  end
100
101  ##
102  #  call-seq:
103  #     str.strip!   -> str or nil
104  #
105  #  Removes leading and trailing whitespace from <i>str</i>. Returns
106  #  <code>nil</code> if <i>str</i> was not altered.
107  #
108  def strip!
109    raise FrozenError, "can't modify frozen String" if frozen?
110    s = self.strip
111    (s == self) ? nil : self.replace(s)
112  end
113
114  ##
115  # call-seq:
116  #    str.casecmp(other_str)   -> -1, 0, +1 or nil
117  #
118  # Case-insensitive version of <code>String#<=></code>.
119  #
120  #    "abcdef".casecmp("abcde")     #=> 1
121  #    "aBcDeF".casecmp("abcdef")    #=> 0
122  #    "abcdef".casecmp("abcdefg")   #=> -1
123  #    "abcdef".casecmp("ABCDEF")    #=> 0
124  #
125  def casecmp(str)
126    self.downcase <=> str.__to_str.downcase
127  rescue NoMethodError
128    nil
129  end
130
131  ##
132  # call-seq:
133  #   str.casecmp?(other)  -> true, false, or nil
134  #
135  # Returns true if str and other_str are equal after case folding,
136  # false if they are not equal, and nil if other_str is not a string.
137
138  def casecmp?(str)
139    c = self.casecmp(str)
140    return nil if c.nil?
141    return c == 0
142  end
143
144  def partition(sep)
145    raise TypeError, "type mismatch: #{sep.class} given" unless sep.is_a? String
146    n = index(sep)
147    unless n.nil?
148      m = n + sep.size
149      [ slice(0, n), sep, slice(m, size - m) ]
150    else
151      [ self, "", "" ]
152    end
153  end
154
155  def rpartition(sep)
156    raise TypeError, "type mismatch: #{sep.class} given" unless sep.is_a? String
157    n = rindex(sep)
158    unless n.nil?
159      m = n + sep.size
160      [ slice(0, n), sep, slice(m, size - m) ]
161    else
162      [ "", "", self ]
163    end
164  end
165
166  ##
167  # call-seq:
168  #    str.slice!(fixnum)           -> new_str or nil
169  #    str.slice!(fixnum, fixnum)   -> new_str or nil
170  #    str.slice!(range)            -> new_str or nil
171  #    str.slice!(other_str)        -> new_str or nil
172  #
173  # Deletes the specified portion from <i>str</i>, and returns the portion
174  # deleted.
175  #
176  #    string = "this is a string"
177  #    string.slice!(2)        #=> "i"
178  #    string.slice!(3..6)     #=> " is "
179  #    string.slice!("r")      #=> "r"
180  #    string                  #=> "thsa sting"
181  #
182  def slice!(arg1, arg2=nil)
183    raise FrozenError, "can't modify frozen String" if frozen?
184    raise "wrong number of arguments (for 1..2)" if arg1.nil? && arg2.nil?
185
186    if !arg1.nil? && !arg2.nil?
187      idx = arg1
188      idx += self.size if arg1 < 0
189      if idx >= 0 && idx <= self.size && arg2 > 0
190        str = self[idx, arg2]
191      else
192        return nil
193      end
194    else
195      validated = false
196      if arg1.kind_of?(Range)
197        beg = arg1.begin
198        ed = arg1.end
199        beg += self.size if beg < 0
200        ed += self.size if ed < 0
201        ed -= 1 if arg1.exclude_end?
202        validated = true
203      elsif arg1.kind_of?(String)
204        validated = true
205      else
206        idx = arg1
207        idx += self.size if arg1 < 0
208        validated = true if idx >=0 && arg1 < self.size
209      end
210      if validated
211        str = self[arg1]
212      else
213        return nil
214      end
215    end
216    unless str.nil? || str == ""
217      if !arg1.nil? && !arg2.nil?
218        idx = arg1 >= 0 ? arg1 : self.size+arg1
219        str2 = self[0...idx] + self[idx+arg2..-1].to_s
220      else
221        if arg1.kind_of?(Range)
222          idx = beg >= 0 ? beg : self.size+beg
223          idx2 = ed>= 0 ? ed : self.size+ed
224          str2 = self[0...idx] + self[idx2+1..-1].to_s
225        elsif arg1.kind_of?(String)
226          idx = self.index(arg1)
227          str2 = self[0...idx] + self[idx+arg1.size..-1] unless idx.nil?
228        else
229          idx = arg1 >= 0 ? arg1 : self.size+arg1
230          str2 = self[0...idx] + self[idx+1..-1].to_s
231        end
232      end
233      self.replace(str2) unless str2.nil?
234    end
235    str
236  end
237
238  ##
239  #  call-seq:
240  #     str.insert(index, other_str)   -> str
241  #
242  #  Inserts <i>other_str</i> before the character at the given
243  #  <i>index</i>, modifying <i>str</i>. Negative indices count from the
244  #  end of the string, and insert <em>after</em> the given character.
245  #  The intent is insert <i>aString</i> so that it starts at the given
246  #  <i>index</i>.
247  #
248  #     "abcd".insert(0, 'X')    #=> "Xabcd"
249  #     "abcd".insert(3, 'X')    #=> "abcXd"
250  #     "abcd".insert(4, 'X')    #=> "abcdX"
251  #     "abcd".insert(-3, 'X')   #=> "abXcd"
252  #     "abcd".insert(-1, 'X')   #=> "abcdX"
253  #
254  def insert(idx, str)
255    if idx == -1
256      return self << str
257    elsif idx < 0
258      idx += 1
259    end
260    self[idx, 0] = str
261    self
262  end
263
264  ##
265  #  call-seq:
266  #     str.ljust(integer, padstr=' ')   -> new_str
267  #
268  #  If <i>integer</i> is greater than the length of <i>str</i>, returns a new
269  #  <code>String</code> of length <i>integer</i> with <i>str</i> left justified
270  #  and padded with <i>padstr</i>; otherwise, returns <i>str</i>.
271  #
272  #     "hello".ljust(4)            #=> "hello"
273  #     "hello".ljust(20)           #=> "hello               "
274  #     "hello".ljust(20, '1234')   #=> "hello123412341234123"
275  def ljust(idx, padstr = ' ')
276    raise ArgumentError, 'zero width padding' if padstr == ''
277    return self if idx <= self.size
278    pad_repetitions = (idx / padstr.length).ceil
279    padding = (padstr * pad_repetitions)[0...(idx - self.length)]
280    self + padding
281  end
282
283  ##
284  #  call-seq:
285  #     str.rjust(integer, padstr=' ')   -> new_str
286  #
287  #  If <i>integer</i> is greater than the length of <i>str</i>, returns a new
288  #  <code>String</code> of length <i>integer</i> with <i>str</i> right justified
289  #  and padded with <i>padstr</i>; otherwise, returns <i>str</i>.
290  #
291  #     "hello".rjust(4)            #=> "hello"
292  #     "hello".rjust(20)           #=> "               hello"
293  #     "hello".rjust(20, '1234')   #=> "123412341234123hello"
294  def rjust(idx, padstr = ' ')
295    raise ArgumentError, 'zero width padding' if padstr == ''
296    return self if idx <= self.size
297    pad_repetitions = (idx / padstr.length).ceil
298    padding = (padstr * pad_repetitions)[0...(idx - self.length)]
299    padding + self
300  end
301
302  def chars(&block)
303    if block_given?
304      self.split('').each do |i|
305        block.call(i)
306      end
307      self
308    else
309      self.split('')
310    end
311  end
312
313  ##
314  # Call the given block for each character of
315  # +self+.
316  def each_char(&block)
317    return to_enum :each_char unless block
318    pos = 0
319    while pos < self.size
320      block.call(self[pos])
321      pos += 1
322    end
323    self
324  end
325
326  def codepoints(&block)
327    len = self.size
328
329    if block_given?
330      self.split('').each do|x|
331        block.call(x.ord)
332      end
333      self
334    else
335      self.split('').map{|x| x.ord}
336    end
337  end
338  alias each_codepoint codepoints
339
340  ##
341  # call-seq:
342  #    str.prepend(other_str)  -> str
343  #
344  # Prepend---Prepend the given string to <i>str</i>.
345  #
346  #    a = "world"
347  #    a.prepend("hello ") #=> "hello world"
348  #    a                   #=> "hello world"
349  def prepend(arg)
350    self[0, 0] = arg
351    self
352  end
353
354  ##
355  #  call-seq:
356  #    string.lines                ->  array of string
357  #    string.lines {|s| block}    ->  array of string
358  #
359  #  Returns strings per line;
360  #
361  #    a = "abc\ndef"
362  #    a.lines    #=> ["abc\n", "def"]
363  #
364  #  If a block is given, it works the same as <code>each_line</code>.
365  def lines(&blk)
366    lines = self.__lines
367    if blk
368      lines.each do |line|
369        blk.call(line)
370      end
371    end
372    lines
373  end
374
375  ##
376  #  call-seq:
377  #     str.upto(other_str, exclusive=false) {|s| block }   -> str
378  #     str.upto(other_str, exclusive=false)                -> an_enumerator
379  #
380  #  Iterates through successive values, starting at <i>str</i> and
381  #  ending at <i>other_str</i> inclusive, passing each value in turn to
382  #  the block. The <code>String#succ</code> method is used to generate
383  #  each value.  If optional second argument exclusive is omitted or is false,
384  #  the last value will be included; otherwise it will be excluded.
385  #
386  #  If no block is given, an enumerator is returned instead.
387  #
388  #     "a8".upto("b6") {|s| print s, ' ' }
389  #     for s in "a8".."b6"
390  #       print s, ' '
391  #     end
392  #
393  #  <em>produces:</em>
394  #
395  #     a8 a9 b0 b1 b2 b3 b4 b5 b6
396  #     a8 a9 b0 b1 b2 b3 b4 b5 b6
397  #
398  #  If <i>str</i> and <i>other_str</i> contains only ascii numeric characters,
399  #  both are recognized as decimal numbers. In addition, the width of
400  #  string (e.g. leading zeros) is handled appropriately.
401  #
402  #     "9".upto("11").to_a   #=> ["9", "10", "11"]
403  #     "25".upto("5").to_a   #=> []
404  #     "07".upto("11").to_a  #=> ["07", "08", "09", "10", "11"]
405  def upto(max, exclusive=false, &block)
406    return to_enum(:upto, max, exclusive) unless block
407    raise TypeError, "no implicit conversion of #{max.class} into String" unless max.kind_of? String
408
409    len = self.length
410    maxlen = max.length
411    # single character
412    if len == 1 and maxlen == 1
413      c = self.ord
414      e = max.ord
415      while c <= e
416        break if exclusive and c == e
417        yield c.chr(__ENCODING__)
418        c += 1
419      end
420      return self
421    end
422    # both edges are all digits
423    bi = self.to_i(10)
424    ei = max.to_i(10)
425    len = self.length
426    if (bi > 0 or bi == "0"*len) and (ei > 0 or ei == "0"*maxlen)
427      while bi <= ei
428        break if exclusive and bi == ei
429        s = bi.to_s
430        s = s.rjust(len, "0") if s.length < len
431        yield s
432        bi += 1
433      end
434      return self
435    end
436    bs = self
437    while true
438      n = (bs <=> max)
439      break if n > 0
440      break if exclusive and n == 0
441      yield bs
442      break if n == 0
443      bs = bs.succ
444    end
445    self
446  end
447end
448