Class: Prime::PseudoPrimeGenerator

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/prime.rb

Overview

An abstract class for enumerating pseudo-prime numbers.

Concrete subclasses should override succ, next, rewind.

Instance Method Summary collapse

Constructor Details

#initialize(ubound = nil) ⇒ PseudoPrimeGenerator

Returns a new instance of PseudoPrimeGenerator


243
244
245
# File 'lib/prime.rb', line 243

def initialize(ubound = nil)
  @ubound = ubound
end

Instance Method Details

#eachObject

Iterates the given block for each prime number.


275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
# File 'lib/prime.rb', line 275

def each
  return self.dup unless block_given?
  if @ubound
    last_value = nil
    loop do
      prime = succ
      break last_value if prime > @ubound
      last_value = yield prime
    end
  else
    loop do
      yield succ
    end
  end
end

#nextObject

alias of succ.

Raises:

  • (NotImplementedError)

263
264
265
# File 'lib/prime.rb', line 263

def next
  raise NotImplementedError, "need to define `next'"
end

#rewindObject

Rewinds the internal position for enumeration.

See Enumerator#rewind.

Raises:

  • (NotImplementedError)

270
271
272
# File 'lib/prime.rb', line 270

def rewind
  raise NotImplementedError, "need to define `rewind'"
end

#succObject

returns the next pseudo-prime number, and move the internal position forward.

PseudoPrimeGenerator#succ raises NotImplementedError.

Raises:

  • (NotImplementedError)

258
259
260
# File 'lib/prime.rb', line 258

def succ
  raise NotImplementedError, "need to define `succ'"
end

#upper_boundObject


250
251
252
# File 'lib/prime.rb', line 250

def upper_bound
  @ubound
end

#upper_bound=(ubound) ⇒ Object


247
248
249
# File 'lib/prime.rb', line 247

def upper_bound=(ubound)
  @ubound = ubound
end

#with_object(obj) ⇒ Object

see Enumerator#with_object.


295
296
297
298
299
300
# File 'lib/prime.rb', line 295

def with_object(obj)
  return enum_for(:with_object) unless block_given?
  each do |prime|
    yield prime, obj
  end
end