

def solve_ordering(nodes):
    " Solve for the desired order of the list of nodes.\n\n    This function is an implementation detail and should not be\n    consumed by code outside of this module.\n\n    Parameters\n    ----------\n    nodes : list\n        The list of PathNode objects which should be ordered. It\n        is assumed that all nodes reside in the same group.\n\n    Returns\n    -------\n    result : list\n        The PathNode objects ordered according to the constraints\n        specified by the 'before' and 'after' items attributes.\n\n    "
    variables = {
        
    }
    for node in nodes:
        variables[node.id] = kiwi.Variable(str(node.id))
    prev_var = None
    constraints = []
    for node in nodes:
        this_var = variables[node.id]
        constraints.append((this_var >= 0))
        if (prev_var is not None):
            constraints.append((((prev_var + 0.1) <= this_var) | 'weak'))
        before = node.item.before
        if before:
            if (before not in variables):
                msg = "item '%s' has invalid `before` reference '%s'"
                raise ValueError((msg % (node.path, before)))
            target_var = variables[before]
            constraints.append((((this_var + 0.1) <= target_var) | 'strong'))
        after = node.item.after
        if after:
            if (after not in variables):
                msg = "item '%s' has invalid `after` reference '%s'"
                raise ValueError((msg % (node.path, after)))
            target_var = variables[after]
            constraints.append((((target_var + 0.1) <= this_var) | 'strong'))
        prev_var = this_var
    solver = kiwi.Solver()
    for cn in constraints:
        solver.addConstraint(prev_var)
    solver.updateVariables()
    flat = []
    for node in nodes:
        node_var = variables[node.id]
        flat.append((node_var.value(), node))
    flat.sort()
    return [pair[1] for pair in flat]

dataset/ETHPy150Open nucleic/enaml/enaml/workbench/ui/menu_helper.py solve_ordering/VarMisuse@278/559 `cn`->`prev_var`