describe "backcall", ->
	it "should support basic backcall with <-", ->
		results = {}
		mock_map = (list, fn) ->
			for item in *list
				table.insert results, fn(item)
		do
			(x) <- mock_map {1, 2, 3}
			x * 2
		assert.same results, {2, 4, 6}

	it "should support nested backcalls", ->
		results = {}
		mock_map = (list, fn) ->
			for item in *list
				fn(item)
		mock_map {1, 2, 3, 4}, (x) ->
			if x > 2
				table.insert results, x
		assert.same results, {3, 4}

	it "should work with method call backcall", ->
		results = {}
		obj = {
			process: (self, fn) ->
				fn 42
		}
		(value) <- obj\process
		table.insert results, value
		assert.same results, {42}