public void ComplexTermsShouldUnifyWithEqualComplexTerms(string str, string cmp, bool expectedLR, bool expectedRL)
{
ITerm left = ErgolParser.Parse(str, ErgolParser.TryParseComplex);
ITerm right = ErgolParser.Parse(cmp, ErgolParser.TryParseComplex);
Assert.Equal(expectedLR, left.UnifyWith(right).TryGetValue(out _));
Assert.Equal(expectedRL, right.UnifyWith(left).TryGetValue(out _));
}
public void KnowledgeBaseShouldMatchFacts()
{
var kb = new InMemoryKnowledgeBase();
kb.AssertLast(ErgolParser.Parse("fact.", ErgolParser.TryParseClause));
kb.AssertLast(ErgolParser.Parse("not_a_fact :--> false.", ErgolParser.TryParseClause));
var res = kb.Solve(ErgolParser.Parse("fact.", ErgolParser.TryParseQuery));
Assert.Single(res.Root.Children);
res = kb.Solve(ErgolParser.Parse("not_a_fact.", ErgolParser.TryParseQuery));
Assert.Empty(res.Root.Children);
}
static void Main(string[] args)
{
var kb = new InMemoryKnowledgeBase();
kb.AssertLast(ErgolParser.Parse("loves(john, jane).", ErgolParser.TryParseClause));
kb.AssertLast(ErgolParser.Parse("loves(jack, jane).", ErgolParser.TryParseClause));
kb.AssertLast(ErgolParser.Parse("jealous(A, B) :-\n\tloves(A, C),\n\tloves(B, C).", ErgolParser.TryParseClause));
Console.Write("?- ");
while (Console.ReadLine() is { } line&& line != "q")
{
try {
if (line.StartsWith(":") && ErgolParser.TryParseClause(line[1..]).TryGetValue(out var clause))
public void VariablesShouldUnifyWithAnything(string variableName, string constantName)
{
var variable = ErgolParser.Parse(variableName, ErgolParser.TryParseVariable);
var otherVariable = ErgolParser.Parse("Other", ErgolParser.TryParseVariable);
ITerm constant = ErgolParser.Parse(constantName, ErgolParser.TryParseConstant);
Assert.True(variable.UnifyWith(variable).TryGetValue(out _));
Assert.True(otherVariable.UnifyWith(otherVariable).TryGetValue(out _));
Assert.True(variable.UnifyWith(otherVariable).TryGetValue(out _));
Assert.True(otherVariable.UnifyWith(variable).TryGetValue(out _));
Assert.True(variable.UnifyWith(constant).TryGetValue(out _));
Assert.False(constant.UnifyWith(variable).TryGetValue(out _));
}
public void KnowledgeBaseShouldSolveJealousXY()
{
var kb = new InMemoryKnowledgeBase();
kb.AssertLast(ErgolParser.Parse("loves(marcellus, mia).", ErgolParser.TryParseClause));
kb.AssertLast(ErgolParser.Parse("loves(vincent, mia).", ErgolParser.TryParseClause));
kb.AssertLast(ErgolParser.Parse("jealous(A, B) :-\n\tloves(A, C),\n\tloves(B, C).", ErgolParser.TryParseClause));
var res = kb.Solve(ErgolParser.Parse("jealous(X, Y).", ErgolParser.TryParseQuery));
var sol = res.Solutions().ToList();
Assert.Equal(4, sol.Count);
Assert.Equal("X = marcellus, Y = marcellus", sol[0].Canonical());
Assert.Equal("X = marcellus, Y = vincent", sol[1].Canonical());
Assert.Equal("X = vincent, Y = marcellus", sol[2].Canonical());
Assert.Equal("X = vincent, Y = vincent", sol[3].Canonical());
}
public void VariablesShouldUnifyThroughAssignment()
{
var kb = new InMemoryKnowledgeBase();
kb.AssertLast(ErgolParser.Parse("fact(a, b).", ErgolParser.TryParseClause));
var res = kb.Solve(ErgolParser.Parse("fact(A, B).", ErgolParser.TryParseQuery));
var sol = res.Solutions().ToList();
Assert.Single(sol);
res = kb.Solve(ErgolParser.Parse("fact(A, A).", ErgolParser.TryParseQuery));
Assert.Null(res.Root);
kb.AssertLast(ErgolParser.Parse("fact(one, one, two).", ErgolParser.TryParseClause));
res = kb.Solve(ErgolParser.Parse("fact(A, A, B).", ErgolParser.TryParseQuery));
sol = res.Solutions().ToList();
Assert.Single(sol);
}
public void ConstantShouldUnifyWithEqualConstants(string _a, string _b, string _c)
{
ITerm a = ErgolParser.Parse(_a, ErgolParser.TryParseConstant);
ITerm b = ErgolParser.Parse(_b, ErgolParser.TryParseConstant);
ITerm c = ErgolParser.Parse(_c, ErgolParser.TryParseConstant);
Assert.True(a.UnifyWith(a).TryGetValue(out _));
Assert.True(b.UnifyWith(b).TryGetValue(out _));
Assert.True(c.UnifyWith(c).TryGetValue(out _));
Assert.True(a.UnifyWith(b).TryGetValue(out _));
Assert.True(b.UnifyWith(a).TryGetValue(out _));
Assert.False(a.UnifyWith(c).TryGetValue(out _));
Assert.False(c.UnifyWith(a).TryGetValue(out _));
Assert.False(b.UnifyWith(c).TryGetValue(out _));
Assert.False(c.UnifyWith(b).TryGetValue(out _));
}