Class: Mon::Monad::FuturePromise

Inherits:
Future show all
Defined in:
lib/monads/future.rb

Overview

FuturePromise represents an asynchronous operation that is still inflight, or complete.

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Future

#==, [], #eql?, #equals?, eventually, valid?

Methods included from ChainableMonad

#_, #coerce, #method_missing, #respond_to?

Constructor Details

#initialize(thread) ⇒ FuturePromise

Returns a new instance of FuturePromise.



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# File 'lib/monads/future.rb', line 74

def initialize(thread)
  @thread = thread
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Mon::Monad::ChainableMonad

Class Method Details

.perform(fun, args) ⇒ Object

Equivalent to calling Future::eventually { … }



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# File 'lib/monads/future.rb', line 79

def self::perform(fun, args)
  if args.length == 1 and args[0].is_a? FuturePromise
    # We're waiting on something, but we don't want to block
    FuturePromise.new(Thread.new { fun.call(args[0].unwrap) })
  else
    FuturePromise.new(Thread.new(args) { |args| fun.call(*args) })
  end
end

Instance Method Details

#bind(&fun) ⇒ Object

Take a block, and apply it to the value asynchronously, returing a future to represent the result



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# File 'lib/monads/future.rb', line 90

def bind &fun
  FuturePromise::perform(fun, [self])
end

#finalize ⇒ Object

Block until the operation completes, then return the result (wrapped as a FutureComplete)



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# File 'lib/monads/future.rb', line 100

def finalize
  value = @thread.value
  FutureComplete[(value.is_a? Future) ? value.unwrap : value]
end

#pending? ⇒ Boolean

Are we still inflight?

Returns:

  • (Boolean) 


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# File 'lib/monads/future.rb', line 106

def pending?
  @thread.alive?
end

#to_s ⇒ Object 



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# File 'lib/monads/future.rb', line 110

def to_s
  "FuturePromise[#{ @thread }]"
end

#unwrap ⇒ Object

Block, then return the result (unwrapped)



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# File 'lib/monads/future.rb', line 95

def unwrap
  @thread.value
end