Class: Promise

Inherits:
Object
  • Object
show all
Includes:
Progress
Defined in:
lib/promise.rb,
lib/promise/group.rb,
lib/promise/version.rb,
lib/promise/callback.rb,
lib/promise/progress.rb

Defined Under Namespace

Modules: Progress

Constant Summary collapse

Error =
Class.new(RuntimeError)
VERSION =
'0.7.0'.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Progress

#on_progress, #progress

Constructor Details

#initializePromise


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# File 'lib/promise.rb', line 25

def initialize
  @state = :pending
  @callbacks = []
end

Instance Attribute Details

#reasonObject (readonly)

Returns the value of attribute reason


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# File 'lib/promise.rb', line 14

def reason
  @reason
end

#stateObject (readonly)

Returns the value of attribute state


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# File 'lib/promise.rb', line 14

def state
  @state
end

#valueObject (readonly)

Returns the value of attribute value


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# File 'lib/promise.rb', line 14

def value
  @value
end

Class Method Details

.all(enumerable) ⇒ Object


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# File 'lib/promise.rb', line 21

def self.all(enumerable)
  Group.new(new, enumerable).promise
end

.resolve(obj) ⇒ Object


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# File 'lib/promise.rb', line 16

def self.resolve(obj)
  return obj if obj.is_a?(self)
  new.tap { |promise| promise.fulfill(obj) }
end

Instance Method Details

#deferObject


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# File 'lib/promise.rb', line 80

def defer
  yield
end

#fulfill(value = nil) ⇒ Object


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# File 'lib/promise.rb', line 61

def fulfill(value = nil)
  if Promise === value
    Callback.assume_state(value, self)
  else
    dispatch do
      @state = :fulfilled
      @value = value
    end
  end
  nil
end

#fulfilled?Boolean


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# File 'lib/promise.rb', line 34

def fulfilled?
  state.equal?(:fulfilled)
end

#pending?Boolean


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# File 'lib/promise.rb', line 30

def pending?
  state.equal?(:pending)
end

#reject(reason = nil) ⇒ Object


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# File 'lib/promise.rb', line 73

def reject(reason = nil)
  dispatch do
    @state = :rejected
    @reason = reason_coercion(reason || Error)
  end
end

#rejected?Boolean


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# File 'lib/promise.rb', line 38

def rejected?
  state.equal?(:rejected)
end

#rescue(&block) ⇒ Object Also known as: catch


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# File 'lib/promise.rb', line 50

def rescue(&block)
  self.then(nil, block)
end

#syncObject


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# File 'lib/promise.rb', line 55

def sync
  wait if pending?
  raise reason if rejected?
  value
end

#then(on_fulfill = nil, on_reject = nil, &block) ⇒ Object


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# File 'lib/promise.rb', line 42

def then(on_fulfill = nil, on_reject = nil, &block)
  on_fulfill ||= block
  next_promise = self.class.new

  add_callback(Callback.new(self, on_fulfill, on_reject, next_promise))
  next_promise
end