class

Talgene::System(T)

Inherits Iterator < Enumerable < Reference < Object

Talgene::System is an iterator over types that define an #advance method. See Talgene::Advanceable module.

require "talgene"

record Integer, value : Int32 do
  include Talgene::Advanceable(Integer)

  def advance : Integer
    Integer.new @value + 1
  end
end

system = Talgene::System.new Integer.new(0)
system.next # => Integer(@value=1)

# Use `include_first` to include the initial entry
system = Talgene::System.new Integer.new(0), include_first: true
system.next # => Integer(@value=0)

Constructors

new(initial current : T, *, max_advances : Int32 | Nil = nil, include_first at_start : Bool = false)

Creates a new Talgene::System instance from an initial value and given options.

When max_advances is nil the iterator never stops. When include_first is true the initial entry is used as first value of the iteration. This will not affect the number of total advances.

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new(initial : T, **options, &)

Creates a new Talgene::System instance and yields with that newly created instance as the default receiver for method calls within the block.

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Instance methods

advances

Returns the number of advances made in the iteration.

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current

Returns the current element of the iteration.

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Returns the next element in this iterator, or Iterator::Stop::INSTANCE if there are no more elements.

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Returns the previous element of the iteration or nil if currently on the first iteration.

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stop_on

Defines an early stop condition that will be checked at every iteration step until max_advances is reached. On condition matched the iterator stops immediately.

It yields the current element, the previous one and the total number of advances made.

require "talgene"

record Integer, value : Int32 do
  include Talgene::Advanceable(Integer)

  def advance : Integer
    Integer.new @value + 1
  end
end

system = Talgene::System.new Integer.new(0)

system.stop_on do |int|
  int.value > 93.0
end

system.size # => 94

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