public void EvaluateWithThreeExpressions()
{
Context context = new Context();
FunExpression expr1 = this.MakeExpression("fun(0) -> 1 end.");
FunExpression expr2 = this.MakeExpression("fun(1) -> 1 end.");
FunExpression expr3 = this.MakeExpression("fun(X) -> f(X-1) + f(X-2) end.");
MultiFunExpression mexpr = new MultiFunExpression(new FunExpression[] { expr1, expr2, expr3 });
var result = mexpr.Evaluate(context);
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(MultiFunction));
var mfunc = (MultiFunction)result;
Assert.IsNotNull(mfunc.Functions);
Assert.AreEqual(3, mfunc.Functions.Count);
}
public void RaiseIfArityIsWrong()
{
Context context = new Context();
FunExpression expr1 = this.MakeExpression("fun(0) -> 1 end.");
FunExpression expr2 = this.MakeExpression("fun(1) -> 1 end.");
FunExpression expr3 = this.MakeExpression("fun(X, Y) -> f(X-1) + f(X-2) end.");
MultiFunExpression mexpr = new MultiFunExpression(new FunExpression[] { expr1, expr2, expr3 });
try
{
mexpr.Evaluate(context);
Assert.Fail();
}
catch (Exception ex)
{
Assert.AreEqual("head mismatch", ex.Message);
}
}
public void EvaluateWithOneExpression()
{
Context context = new Context();
FunExpression expr = this.MakeExpression("fun(0) -> 1 end.");
MultiFunExpression mexpr = new MultiFunExpression(new FunExpression[] { expr });
Assert.IsFalse(mexpr.HasVariable());
var result = mexpr.Evaluate(context);
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(MultiFunction));
var mfunc = (MultiFunction)result;
Assert.IsNotNull(mfunc.Functions);
Assert.AreEqual(1, mfunc.Functions.Count);
}
public void DefineAndEvaluateFunction()
{
FunExpression expr = new FunExpression(new IExpression[] { new VariableExpression(new Variable("X")), new VariableExpression(new Variable("Y")) }, new AddExpression(new VariableExpression(new Variable("X")), new VariableExpression(new Variable("Y"))));
Context context = new Context();
Assert.IsFalse(expr.HasVariable());
var result = expr.Evaluate(context);
Assert.IsNotNull(result);
Assert.IsInstanceOfType(result, typeof(Function));
var func = (Function)result;
var newcontext = func.MakeContext(new object[] { 1, 2 });
Assert.IsNotNull(newcontext);
Assert.AreEqual(1, newcontext.GetValue("X"));
Assert.AreEqual(2, newcontext.GetValue("Y"));
Assert.AreEqual(3, func.Evaluate(newcontext));
}
