private IEnumerable<Holder> FindCandidates(MethodDeclaration right, int count)
{
var rights_primitives = right.AllPrimitiveExpressions();
// Find all PrimitiveExpressions except the keyword 'null'
IEnumerable<PrimitiveExpression> primitives = rights_primitives.Where(x => x.ValueType != null);
// find the position of each primitive
var prims_with_position = from p in primitives
select new {p.Value, p.ValueType, Index = rights_primitives.IndexOf(p)};
// Group them together by literal value. The groups then are candidates for replacement by a single param.
var prim_groups = from p in prims_with_position
group p by new {p.Value, p.ValueType}
into g select new PrimExpSet {Value = g.Key.Value, ValueType = g.Key.ValueType, Positions = g.Select(x => x.Index)};
// The powerset of the primitive positions is all the possible ways a single primitive value can be converted to a param.
var all_param_possibles = from pes in prim_groups
let expanded = from positions in Sets<int>.PowerSet(pes.Positions.ToArray())
select new PrimExpSet {Value = pes.Value, ValueType = pes.ValueType, Positions = positions}
select expanded;
foreach (var e1 in Sets<PrimExpSet>.CartesianProduct(all_param_possibles, count))
{
// If count is neg, let anything through.
if (count < 0 || e1.Count() == count)
{
var md = MakePermutation(right, e1);
const string QUOTE = "\"";
var parameters = e1.Select(x => x.ValueType == typeof (string) ? QUOTE + x.Value + QUOTE : x.Value).ToList();
yield return new Holder {md = md, parameters = parameters};
}
}
}
private MethodDeclaration MakePermutation(MethodDeclaration right, IEnumerable<PrimExpSet> prim_groups)
{
ResetNameCount();
right = right.DeepCopy();
var rights_primitives = right.AllPrimitiveExpressions();
foreach (var prim_grp in prim_groups)
{
var param_name = NextName();
var typeRef = new TypeReference(prim_grp.ValueType.FullName);
right.Parameters.Add(new ParameterDeclarationExpression(typeRef, param_name));
var replacer = new PrimitiveReplacer();
foreach (var pos in prim_grp.Positions)
{
replacer.AddReplacement(rights_primitives[pos], new IdentifierExpression(param_name));
}
right.AcceptVisitor(replacer, null);
}
return right;
}