summaryrefslogtreecommitdiff
path: root/numeric.rb
blob: c892cbe6ef85dde38ec47b4b886df5132976e9de (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
class Numeric
  #
  #  call-seq:
  #     num.real?  ->  true or false
  #
  #  Returns +true+ if +num+ is a real number (i.e. not Complex).
  #
  def real?
    return true
  end

  #
  #  call-seq:
  #     num.integer?  ->  true or false
  #
  #  Returns +true+ if +num+ is an Integer.
  #
  #      1.0.integer?   #=> false
  #      1.integer?     #=> true
  #
  def integer?
    return false
  end

  #
  #  call-seq:
  #     num.finite?  ->  true or false
  #
  #  Returns +true+ if +num+ is a finite number, otherwise returns +false+.
  #
  def finite?
    return true
  end

  #
  #  call-seq:
  #     num.infinite?  ->  -1, 1, or nil
  #
  #  Returns +nil+, -1, or 1 depending on whether the value is
  #  finite, <code>-Infinity</code>, or <code>+Infinity</code>.
  #
  def infinite?
    return nil
  end
end

class Integer
  # call-seq:
  #    -int  ->  integer
  #
  # Returns +int+, negated.
  def -@
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_uminus(self)'
  end

  # call-seq:
  #   ~int  ->  integer
  #
  # One's complement: returns a number where each bit is flipped.
  #
  # Inverts the bits in an Integer. As integers are conceptually of
  # infinite length, the result acts as if it had an infinite number of
  # one bits to the left. In hex representations, this is displayed
  # as two periods to the left of the digits.
  #
  #   sprintf("%X", ~0x1122334455)    #=> "..FEEDDCCBBAA"
  def ~
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_comp(self)'
  end

  def abs
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_abs(self)'
  end

  # call-seq:
  #    int.bit_length  ->  integer
  #
  # Returns the number of bits of the value of +int+.
  #
  # "Number of bits" means the bit position of the highest bit
  # which is different from the sign bit
  # (where the least significant bit has bit position 1).
  # If there is no such bit (zero or minus one), zero is returned.
  #
  # I.e. this method returns <i>ceil(log2(int < 0 ? -int : int+1))</i>.
  #
  #    (-2**1000-1).bit_length   #=> 1001
  #    (-2**1000).bit_length     #=> 1000
  #    (-2**1000+1).bit_length   #=> 1000
  #    (-2**12-1).bit_length     #=> 13
  #    (-2**12).bit_length       #=> 12
  #    (-2**12+1).bit_length     #=> 12
  #    -0x101.bit_length         #=> 9
  #    -0x100.bit_length         #=> 8
  #    -0xff.bit_length          #=> 8
  #    -2.bit_length             #=> 1
  #    -1.bit_length             #=> 0
  #    0.bit_length              #=> 0
  #    1.bit_length              #=> 1
  #    0xff.bit_length           #=> 8
  #    0x100.bit_length          #=> 9
  #    (2**12-1).bit_length      #=> 12
  #    (2**12).bit_length        #=> 13
  #    (2**12+1).bit_length      #=> 13
  #    (2**1000-1).bit_length    #=> 1000
  #    (2**1000).bit_length      #=> 1001
  #    (2**1000+1).bit_length    #=> 1001
  #
  # This method can be used to detect overflow in Array#pack as follows:
  #
  #    if n.bit_length < 32
  #      [n].pack("l") # no overflow
  #    else
  #      raise "overflow"
  #    end
  def bit_length
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_bit_length(self)'
  end

  #  call-seq:
  #     int.even?  ->  true or false
  #
  #  Returns +true+ if +int+ is an even number.
  def even?
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_even_p(self)'
  end

  #  call-seq:
  #     int.integer?  ->  true
  #
  #  Since +int+ is already an Integer, this always returns +true+.
  def integer?
    return true
  end

  def magnitude
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_abs(self)'
  end

  #  call-seq:
  #     int.odd?  ->  true or false
  #
  #  Returns +true+ if +int+ is an odd number.
  def odd?
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_odd_p(self)'
  end

  #  call-seq:
  #     int.ord  ->  self
  #
  #  Returns the +int+ itself.
  #
  #     97.ord   #=> 97
  #
  #  This method is intended for compatibility to character literals
  #  in Ruby 1.9.
  #
  #  For example, <code>?a.ord</code> returns 97 both in 1.8 and 1.9.
  def ord
    return self
  end

  #
  #  Document-method: Integer#size
  #  call-seq:
  #     int.size  ->  int
  #
  #  Returns the number of bytes in the machine representation of +int+
  #  (machine dependent).
  #
  #     1.size               #=> 8
  #     -1.size              #=> 8
  #     2147483647.size      #=> 8
  #     (256**10 - 1).size   #=> 10
  #     (256**20 - 1).size   #=> 20
  #     (256**40 - 1).size   #=> 40
  #
  def size
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_size(self)'
  end

  #  call-seq:
  #     int.to_i    ->  integer
  #
  #  Since +int+ is already an Integer, returns +self+.
  #
  #  #to_int is an alias for #to_i.
  def to_i
    return self
  end

  #  call-seq:
  #     int.to_int  ->  integer
  #
  #  Since +int+ is already an Integer, returns +self+.
  def to_int
    return self
  end

  # call-seq:
  #    int.zero? -> true or false
  #
  # Returns +true+ if +int+ has a zero value.
  def zero?
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_int_zero_p(self)'
  end
end

class Float
  #
  # call-seq:
  #    float.to_f  ->  self
  #
  # Since +float+ is already a Float, returns +self+.
  #
  def to_f
    return self
  end

  #
  #  call-seq:
  #     float.abs        ->  float
  #     float.magnitude  ->  float
  #
  #  Returns the absolute value of +float+.
  #
  #     (-34.56).abs   #=> 34.56
  #     -34.56.abs     #=> 34.56
  #     34.56.abs      #=> 34.56
  #
  #  Float#magnitude is an alias for Float#abs.
  #
  def abs
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_float_abs(self)'
  end

  def magnitude
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_float_abs(self)'
  end

  #
  # call-seq:
  #    -float  ->  float
  #
  # Returns +float+, negated.
  #
  def -@
    Primitive.attr! 'inline'
    Primitive.cexpr! 'rb_float_uminus(self)'
  end

  #
  #  call-seq:
  #     float.zero?  ->  true or false
  #
  #  Returns +true+ if +float+ is 0.0.
  #
  def zero?
    Primitive.attr! 'inline'
    Primitive.cexpr! 'FLOAT_ZERO_P(self) ? Qtrue : Qfalse'
  end

  #
  #  call-seq:
  #     float.positive?  ->  true or false
  #
  #  Returns +true+ if +float+ is greater than 0.
  #
  def positive?
    Primitive.attr! 'inline'
    Primitive.cexpr! 'RFLOAT_VALUE(self) > 0.0 ? Qtrue : Qfalse'
  end

  #
  #  call-seq:
  #     float.negative?  ->  true or false
  #
  #  Returns +true+ if +float+ is less than 0.
  #
  def negative?
    Primitive.attr! 'inline'
    Primitive.cexpr! 'RFLOAT_VALUE(self) < 0.0 ? Qtrue : Qfalse'
  end
end