public void EvaluateMultiFunctionWithTwoFunctions()
{
Function func1 = this.MakeFunction("f(0) -> 1.");
Function func2 = this.MakeFunction("f(1) -> 2.");
MultiFunction mfunc = new MultiFunction(new Function[] { func1, func2 });
Assert.AreEqual(2, mfunc.Apply(null, new object[] { 1 }));
}
public void EvaluateMultiFunctionWithOneFunction()
{
Function func = this.MakeFunction("f(0) -> 1.");
MultiFunction mfunc = new MultiFunction(new Function[] { func });
Assert.IsNotNull(mfunc.Functions);
Assert.AreEqual(1, mfunc.Functions.Count);
Assert.AreEqual(1, mfunc.Apply(null, new object[] { 0 }));
}
public void RaiseIfNoClauseToMatch()
{
Function func1 = this.MakeFunction("f(0) -> 1.");
Function func2 = this.MakeFunction("f(1) -> 2.");
MultiFunction mfunc = new MultiFunction(new Function[] { func1, func2 });
try
{
mfunc.Apply(null, new object[] { 2 });
Assert.Fail();
}
catch (Exception ex)
{
Assert.AreEqual("no function clause to match", ex.Message);
}
}
public object Evaluate(Context context, bool withvars = false)
{
int arity = this.expressions[0].ParameterExpressions.Count;
if (!this.expressions.Skip(1).All(f => f.ParameterExpressions.Count == arity))
throw new Exception("head mismatch");
IList<Function> functions = new List<Function>();
foreach (var form in this.Expressions)
functions.Add((Function)form.Evaluate(context, true));
var func = new MultiFunction(functions);
return func;
}
public object Evaluate(Context context)
{
string name = this.forms[0].Name;
int arity = this.forms[0].ParameterExpressions.Count;
if (!this.forms.Skip(1).All(f => f.Name == name && f.ParameterExpressions.Count == arity))
throw new Exception("head mismatch");
IList<Function> functions = new List<Function>();
foreach (var form in this.Forms)
functions.Add((Function)form.Evaluate(context));
var func = new MultiFunction(functions);
context.SetValue(string.Format("{0}/{1}", name, arity), func);
return func;
}