public static LithpOpChain Factorial()
{
// (
LithpOpChain result = new LithpOpChain();
// (if (== 1 N) (
// (1)
// ) (else (
// (* N (fac (- N 1)))
// )))
LithpOpChain facBody = new LithpOpChain(result);
LithpOpChain return1 = new LithpOpChain(facBody);
return1.Add(new LithpLiteral(1));
LithpOpChain elseBody = new LithpOpChain(facBody);
elseBody.Add(
LithpFunctionCall.New("*/*",
LithpFunctionCall.New("get/1", new LithpVariableReference("N")),
LithpFunctionCall.New("fac/1",
LithpFunctionCall.New("-/*",
LithpFunctionCall.New("get/1", new LithpVariableReference("N")),
new LithpLiteral(1)
)
)
)
);
facBody.Add(
LithpFunctionCall.New("if/3",
LithpFunctionCall.New("==/2",
new LithpLiteral(1),
LithpFunctionCall.New("get/1", new LithpVariableReference("N"))
),
return1,
LithpFunctionCall.New("else/1", elseBody)
)
);
// (def fac #N :: (
LithpFunctionCall def = LithpFunctionCall.New("def/2", LithpAtom.Atom("fac"),
LithpFunctionDefinition.New(result, "fac", facBody, "N")
);
// )
result.Add(def);
int n;
#if DEBUG
n = 10;
#else
n = 500;
#endif
result.Add(LithpFunctionCall.New("print/*", "Factorial result: ", LithpFunctionCall.New("fac/1", n)));
return(result);
}
static void RunTests()
{
LithpOpChain chain = new LithpOpChain();
LithpInteger one = 1;
LithpAtom test = "test";
LithpDict dict = new LithpDict();
dict["foo"] = "bar";
dict["num"] = 1;
dict["list"] = LithpList.New("Hello, world!", one, test);
Console.WriteLine(dict.ToLiteral());
LithpFunctionCall fncall = LithpFunctionCall.New("print/*", dict);
Console.WriteLine("fncall tostring: {0}", fncall);
LithpBuiltins builtins = new LithpBuiltins();
LithpInterpreter interp = new LithpInterpreter();
builtins[fncall.Function].Invoke(fncall.Parameters, chain, interp);
// Now put it all together
chain.Add(fncall);
chain.ImportBuiltins(builtins);
Console.WriteLine("Result of print: {0}", interp.Run(chain));
// More complex
LithpFunctionCall addStrings = LithpFunctionCall.New("+/*", "foo", "bar");
LithpFunctionCall printAddString = LithpFunctionCall.New("print/*",
"Adding two strings: ", addStrings);
chain.Add(printAddString);
interp.Run(chain);
chain.Add(addStrings);
Console.WriteLine("Result of add strings: {0}", interp.Run(chain));
LithpFunctionCall setVar = LithpFunctionCall.New("set/2",
new LithpVariableReference("Test"), "Foo");
LithpFunctionCall printVar = LithpFunctionCall.New("print/*",
"Value of Test:", LithpFunctionCall.New(
"get/1", new LithpVariableReference("Test")
));
chain.Add(setVar);
chain.Add(printVar);
// Now run entire chain from the start
chain.Rewind();
interp.Run(chain);
// Try a user-defined function
LithpOpChain addBody = new LithpOpChain(chain);
addBody.Add(LithpFunctionCall.New(
LithpAtom.Atom("+/*"),
LithpFunctionCall.New("get/1", new LithpVariableReference("A")),
LithpFunctionCall.New("get/1", new LithpVariableReference("B"))
));
chain.Add(LithpFunctionCall.New("def/2",
LithpAtom.Atom("add"),
LithpFunctionDefinition.New(chain, "add", addBody, "A", "B")
));
chain.Add(LithpFunctionCall.New("print/*",
"Calling user function add:", LithpFunctionCall.New(
"add/2", 2, 5
)
));
interp.Run(chain);
}