public override LispObject Eval(Cons body, LispEnvironment env)
{
var varForms = body.Car.As<Cons>();
var varSymbols = varForms.Select(x => x.As<Cons>().Car.As<Symbol>()).ToList();
var varInitForms = varForms.Select(x => x.As<Cons>().Cdr.As<Cons>().Car).ToList();
var varStepForms = varForms.Select(x => x.As<Cons>().Cdr.As<Cons>().Cdr.As<Cons>().Car).ToList();
var cadr = body.Cdr.As<Cons>().Car.As<Cons>();
var testForm = cadr.Car;
var resultForms = cadr.Cdr.As<Cons>();
var doBody = body.Cdr.As<Cons>().Cdr.As<Cons>();
var doEnv = new LispEnvironment(env);
SetInitValues(doEnv, varSymbols, varInitForms);
while (doEnv.Eval(testForm).IsNil)
{
new Progn().Eval(doBody, doEnv);
SetStepValues(doEnv, varSymbols, varStepForms);
}
return new Progn().Eval(resultForms, doEnv);
}
public override LispObject Eval(Cons body, LispEnvironment env)
{
var lambdaList = body.Car.As<Cons>();
var progn = Progn.Wrap(body.Cdr.As<Cons>(), env);
return new Lambda(lambdaList, progn, env);
}
protected override void SetInitValues(LispEnvironment doEnv, List<Symbol> varSymbols, List<LispObject> varInitForms)
{
for (int i = 0; i < varSymbols.Count; i++)
{
var val = doEnv.Eval(varInitForms[i]);
doEnv.AddBinding(varSymbols[i], val);
}
}
protected override void SetStepValues(LispEnvironment doEnv, List<Symbol> varSymbols, List<LispObject> varStepForms)
{
for (int i = 0; i < varSymbols.Count; i++)
{
var val = doEnv.Eval(varStepForms[i]);
doEnv.SetValue(varSymbols[i], val);
}
}
public override LispObject Apply(Cons argumentValues, LispEnvironment env)
{
var fun = argumentValues.Car.As<Function>();
var args = argumentValues.Cdr.As<Cons>();
var spread = Spread(args);
return fun.Apply(spread, env);
}
protected virtual void SetStepValues(LispEnvironment doEnv, List<Symbol> varSymbols, List<LispObject> varStepForms)
{
var stepValues = varStepForms.Select(doEnv.Eval).ToList();
for (int i = 0; i < varSymbols.Count; i++)
{
doEnv.SetValue(varSymbols[i], stepValues[i]);
}
}
public Repl(TextReader input, TextWriter output)
{
this.environment = new LibraryEnvironment(reader);
this.stars = InternStars();
this.input = input;
this.output = output;
}
public override LispObject Eval(Cons body, LispEnvironment env)
{
var symbol = Car.Of(body).As<Symbol>();
var value = env.Eval(Car.Of(Cdr.Of(body)));
env.SetValue(symbol, value);
return value;
}
public override LispObject Apply(Cons arguments, LispEnvironment env)
{
if (arguments.Car.IsAtom)
{
return T.True;
}
return LispNull.Nil;
}
protected virtual void SetInitValues(LispEnvironment doEnv, List<Symbol> varSymbols, List<LispObject> varInitForms)
{
var varInitValues = varInitForms.Select(doEnv.Eval).ToList();
for (int i = 0; i < varSymbols.Count; i++)
{
doEnv.AddBinding(varSymbols[i], varInitValues[i]);
}
}
public LispEnvironment(LispEnvironment parent)
{
this.parent = parent;
this.symbols = parent.symbols;
this.specials = parent.specials;
if (Level >= 256)
{
throw new EnvironmentException("Stack overflow!");
}
}
public override LispObject Apply(Cons argumentsValues, LispEnvironment env)
{
LispNumber sum = new LispInteger(0);
foreach (var addend in argumentsValues)
{
var num = addend.As<LispNumber>();
sum = sum.Add(num);
}
return sum;
}
public override LispObject Eval(Cons body, LispEnvironment env)
{
var testForm = Car.Of(body);
var thenForm = Car.Of(Cdr.Of(body));
var elseForm = Car.Of(Cdr.Of(Cdr.Of(body)));
if (env.Eval(testForm).IsTrue)
{
return env.Eval(thenForm);
}
return env.Eval(elseForm);
}
public override LispObject Eval(Cons defmacroBody, LispEnvironment env)
{
var symbol = defmacroBody.Car.As<Symbol>();
var lambdaList = Car.Of(Cdr.Of(defmacroBody));
var macroBody = Cdr.Of(Cdr.Of(defmacroBody)).As<Cons>();
var progn = Progn.Wrap(macroBody, env);
var macro = new Macro(symbol.Name, lambdaList, progn, env);
env.AddBinding(symbol, macro);
return macro;
}
public override LispObject Apply(Cons arguments, LispEnvironment env)
{
var argList = new List<LispObject>(arguments);
if (argList.Count < 2)
{
throw new EvaluateException("Too few arguments to " + this.Name);
}
if (argList.Count > 2)
{
throw new EvaluateException("Too many arguments to " + this.Name);
}
return argList[0].As<LispNumber>().DivideBy(argList[1].As<LispNumber>());
}
public override LispObject Apply(Cons arguments, LispEnvironment env)
{
if (arguments.IsNil)
{
throw new EvaluationException("Too few arguments to " + Name);
}
if (arguments.Cdr.IsNil)
{
return arguments.Car.As<LispNumber>().Negate();
}
var difference = arguments.Car.As<LispNumber>();
foreach (var subtrahend in arguments.Cdr.As<Cons>())
{
difference = difference.Add(subtrahend.As<LispNumber>().Negate());
}
return difference;
}
public override LispObject Apply(Cons arguments, LispEnvironment env)
{
if (arguments.IsNil)
{
throw new EvaluationException("Too few arguments to " + Name);
}
var previous = arguments.Car.As<LispNumber>();
foreach (var arg in arguments.Cdr.As<Cons>())
{
var num = arg.As<LispNumber>();
if (!test(previous, num))
{
return LispNull.Nil;
}
previous = num;
}
return T.True;
}
public Cons Expand(Cons form, LispEnvironment env)
{
var argumentValues = form.Cdr.As<Cons>();
return this.expander.Apply(argumentValues, this.macroEnv).As<Cons>();
}
public Macro(string name, LispObject lambdaList, Cons macroBody, LispEnvironment macroEnv)
{
this.name = name;
this.expander = new Lambda(lambdaList, macroBody, macroEnv);
this.macroEnv = macroEnv;
}
public override LispObject Apply(Cons argumentValues, LispEnvironment env)
{
return Car.Of(argumentValues.Car);
}
public override LispObject Apply(Cons arguments, LispEnvironment env)
{
return env.Eval(arguments.Car);
}
public IntegrationTest()
{
this.reader = new Reader();
this.env = new LibraryEnvironment(this.reader);
}
public override LispObject Apply(Cons arguments, LispEnvironment env)
{
return fun();
}
private LispEnvironment GetLoopEnvironment(Action action)
{
var symbol = environment.Symbols.Intern("QUIT");
var builtin = new DelegateBuiltin(symbol.Name, () => { action(); return T.True; });
var loopEnv = new LispEnvironment(environment);
loopEnv.AddBinding(symbol, builtin);
for (int i = 0; i < stars.Length; i++)
{
loopEnv.AddBinding(stars[i], LispNull.Nil);
}
return loopEnv;
}
public override LispObject Eval(Cons body, LispEnvironment env)
{
return Car.Of(body);
}
public abstract LispObject Eval(Cons body, LispEnvironment env);
