private static DisjunctiveExamplesSpec deduceSubstrBasedKey(FunctionalDisjunctiveOutputSpec spec, ComparatorCreator cmpCreator)
{
var strExamples = new Dictionary <State, IEnumerable <object> >();
foreach (State input in spec.ProvidedInputs)
{
var validStrings = new List <string>();
var relation = spec.Relation[input];
var superString = "";
// To find a super-string, find a mapping that contains exactly
// one value (i.e. a strict ordering)
foreach (var mapping in relation)
{
var key = (Tuple <string, string>)mapping.Key;
var possibleResults = mapping.Value;
if (possibleResults.Count == 1)
{
var resultsEnumerator = possibleResults.GetEnumerator();
resultsEnumerator.MoveNext();
var onlyResult = (int)resultsEnumerator.Current;
if (onlyResult == 0)
{
throw new Exception("strict comparisons cannot be zero");
}
// If we have found a strict ordering, the super-string is
// the item corresponding to the larger value
superString = (string)((onlyResult > 0) ? key.Item1 : key.Item2);
break;
}
}
if (superString.Length == 0)
{
throw new Exception("No strict ordering found");
}
// Generate all possible sub-strings from superString
for (var i = 0; i < superString.Length - 1; i++)
{
for (var len = 1; i + len <= superString.Length; len++)
{
// Extract sub-string
var subStr = superString.Substring(i, len);
// Create comparator from provided lambda
var cmp = cmpCreator(subStr);
// Check if this subStr is consistent for all mappings
if (validateComparator(relation, cmp))
{
validStrings.Add(subStr);
}
}
}
strExamples[input] = validStrings;
}
return(DisjunctiveExamplesSpec.From(strExamples));
}
public static DisjunctiveExamplesSpec WitnessLastStr(GrammarRule rule, FunctionalDisjunctiveOutputSpec spec)
{
return(deduceSubstrBasedKey(spec, s => Semantics.Semantics.Last(s)));
}