Class: Stream::IntervalStream

Inherits:
BasicStream show all
Defined in:
lib/stream.rb

Overview

A simple Iterator for iterating over a sequence of integers starting from zero up to a given upper bound. Mainly used by Stream::FilteredStream. Could be made private but if somebody needs it here it is. Is there a better name for it?

The upper bound is stored in the instance variable @stop which can be incremented dynamically by the method increment_stop.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Stream

#+, #backward, #collect, #concatenate, #concatenate_collected, #create_stream, #current, #current_edge, #each, #empty?, #filtered, #first, #forward, #last, #modify, #move_backward_until, #move_forward_until, #peek, #remove_first, #remove_last, #reverse, #unwrapped

Methods included from Enumerable

#create_stream

Constructor Details

#initialize(stop = 0) ⇒ IntervalStream

Create a new IntervalStream with upper bound stop. stop - 1 is the last element. By default stop is zero which means that the stream is empty.



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# File 'lib/stream.rb', line 186

def initialize(stop=0)
  @stop = stop - 1
  set_to_begin
end

Instance Attribute Details

#pos ⇒ Object (readonly)

Returns the value of attribute pos.



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# File 'lib/stream.rb', line 182

def pos
  @pos
end

Instance Method Details

#at_beginning? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/stream.rb', line 191

def at_beginning?; @pos < 0; end

#at_end? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/stream.rb', line 192

def at_end?; @pos == @stop; end

#basic_backward ⇒ Object 



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# File 'lib/stream.rb', line 201

def basic_backward;  @pos -= 1; @pos + 1; end

#basic_forward ⇒ Object 



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# File 'lib/stream.rb', line 200

def basic_forward; @pos += 1; end

#increment_stop(incr = 1) ⇒ Object

Increment the upper bound by incr.



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# File 'lib/stream.rb', line 198

def increment_stop(incr=1); @stop += incr; end

#set_to_begin ⇒ Object 



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# File 'lib/stream.rb', line 195

def set_to_begin; @pos = -1; end

#set_to_end ⇒ Object 



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# File 'lib/stream.rb', line 194

def set_to_end; @pos = @stop; end