tests/org.eclipse.qvtd.atl.tests/models/tree2list/Tree2List_usingATLResolveAlgorithm.atl

-- @name Tree structure to List structure (using ATL Resolve Algorithm)
-- @version 1.0
-- @domains 
-- @authors Cyril Faure, Freddy Allilaire
-- @date 01/07/2007
-- @description "toy example" of model transformation usually made with a DFS (Depth First Search) imperative algorithms
-- @see http://en.wikipedia.org/wiki/Depth-first_search
-- @path MMTree=/Tree2List/metamodels/MMTree.ecore
-- @path MMElementList=/Tree2List/metamodels/MMElementList.ecore

module Tree2List;
create elmList : MMElementList from aTree : MMTree;

uses Lib4MMTree;

-- we want to process the tree via DFS and create an ordered list containing :
-- all big leafs, then all medium leafs, then all small leafs. We add the
-- constraint we want all three "sublists" to be ordered on the DFS traversal order
-- Note : the nodes (other than the tree root) are not kept in the destination model

-- Rule to transform "Tree Node Root" in "Element List Root"
rule TreeNodeRoot2RootElement { 
	from 	-- should be unique
		rt : MMTree!Node (rt.isTreeNodeRoot()) 
	to
		lstRt : MMElementList!RootElement (
			name <- rt.name,
			elements <- rt.getLeavesInOrder() -- reference copy,
			-- Correspondance "Leaf to CommonElement" will be made thanks to a traceability link.
			-- Traceability links record correspondences between source and target elements established during transformation execution.
		)
}

-- Rule to transform Leaf to CommonElement
rule Leaf2CommonElement {
	from
		s : MMTree!Leaf
	to
		t : MMElementList!CommonElement(
			name <- s.name
		)
}