The problem was that the expression to be evaluated (predicate.call(a)
) was drawn from one CompModule
object (namely the predicate
function was taken from there) while the solution object, against which the expression was evaluated, was not obtained from the same CompModule, but was read from a file.
Generally, when reading a solution from an xml file, to be on the safe side, it is recommended to reread and reconstruct everything from that xml file, e.g.,
XMLNode xmlNode = new XMLNode(new File("my_solution.xml"));
String alloySourceFilename = xmlNode.iterator().next().getAttribute("filename");
Module module = CompUtil.parseEverything_fromFile(rep, null, alloySourceFilename);
A4Solution ans = A4SolutionReader.read(module.getAllReachableSigs(), xmlNode);
In some cases it suffices to just pass the sigs from the original CompModule to the reconstructed solution:
XMLNode xmlNode = new XMLNode(new File("my_solution.xml"));
A4Solution ans = A4SolutionReader.read(originalModule.getAllReachableSigs(), xmlNode);