private static void Define(Evaluator eval, StackFrame frame)
{
var(sym, value, context) = StructureUtils.Split3(frame.args);
if (sym.type != AtomType.Symbol)
{
throw new ArgumentException("Definition name must be symbol!");
}
if (eval.HaveReturn())
{
string name = (string)sym.value;
Atom result = eval.TakeReturn();
Context ctx = context?.value as Context ?? frame.context.value as Context;
if (result?.value is Closure function)
{
function.Name = name;
}
//Console.WriteLine($"DEFINE: '{name}' = '{result}' at -internal-state-{ctx}");
ContextUtils.Define(ctx, result, name);
eval.Return(result);
return;
}
eval.CreateFrame("-eval-", value, frame.context);
frame.state = Atoms.INTERNAL_STATE;
}
private static void Open(Evaluator eval, StackFrame frame)
{
var(path, accessType, modeType) = StructureUtils.Split3(frame.args);
if (path == null || !path.IsString)
{
throw new ArgumentException("Path must be string!");
}
string file = (string)path.value;
FileAccess access = ArgUtils.GetEnum <FileAccess>(accessType, 1, FileAccess.Read);
FileMode mode = ArgUtils.GetEnum <FileMode>(modeType, 2, FileMode.Open);
if (access == FileAccess.Read)
{
StreamReader reader = new StreamReader(File.Open(file, mode, access));
eval.Return(new Atom(AtomType.Native, reader));
return;
}
if (access == FileAccess.Write)
{
StreamWriter writer = new StreamWriter(File.Open(file, mode, access));
eval.Return(new Atom(AtomType.Native, writer));
return;
}
eval.Return(null);
}
public static void Substr(Evaluator eval, StackFrame frame)
{
var(strArg, starts, length) = StructureUtils.Split3(frame.args);
// if (!strArg.IsString) throw new ArgumentException("first argument must be string!");
// if (!starts.IsNumber) throw new ArgumentException("second argument must be string!");
// if (!length.IsNumber) throw new ArgumentException("third argument must be string!");
string str = strArg.value as string;
string res = str.Substring((int)starts.value, (int)length.value);
eval.Return(new Atom(AtomType.String, res));
}
private static void Filter(Evaluator eval, StackFrame frame)
{
(var list, var proc, var skip) = StructureUtils.Split3(frame.args);
bool skipNull = (bool?)skip?.value ?? false;
switch (frame.state.value)
{
case "-eval-sexp-body-":
frame.temp1 = list;
frame.state = new Atom("-built-in-map-");
break;
case "-built-in-map-":
if (eval.HaveReturn())
{
var pred = eval.TakeReturn();
bool add = (bool?)pred?.value ?? false;
if (add)
{
frame.temp2 = StructureUtils.BuildListContainer(frame.temp2, frame.temp3);
}
}
if (frame.temp1 != null)
{
while (skipNull && frame.temp1.atom == null)
{
frame.temp1 = frame.temp1.next;
}
var subExpression = frame.temp1.atom;
frame.temp3 = subExpression;
frame.temp1 = frame.temp1.next;
subExpression = new Atom(subExpression, null);
frame.temp1 = frame.temp1.next;
var newFrame = eval.CreateFrame(
"-eval-sexp-args-",
new Atom(proc, subExpression),
frame.context);
newFrame.function = proc;
newFrame.args = subExpression;
}
else
{
eval.SetReturn(frame.temp2.atom);
frame.state = new Atom("-eval-sexp-body-");
}
break;
}
}
public static void Replace(Evaluator eval, StackFrame frame)
{
var(strArg, subArg, newArg) = StructureUtils.Split3(frame.args);
// if (!strArg.IsString) throw new ArgumentException("first argument must be string!");
// if (!subArg.IsString) throw new ArgumentException("second argument must be string!");
// if (!newArg.IsString) throw new ArgumentException("third argument must be string!");
string str = strArg.value as string;
string sub = subArg.value as string;
string n_w = newArg.value as string;
string res = str.Replace(sub, n_w);
eval.Return(new Atom(AtomType.String, res));
}
private static void Each(Evaluator eval, StackFrame frame)
{
(var list, var proc, var skip) = StructureUtils.Split3(frame.args);
bool skipNull = (bool?)skip?.value ?? false;
switch (frame.state.value)
{
case "-eval-sexp-body-":
frame.temp1 = list;
frame.state = new Atom("-built-in-each-");
break;
case "-built-in-each-":
if (eval.HaveReturn())
{
frame.temp2 = StructureUtils.BuildListContainer(frame.temp2, eval.TakeReturn());
}
if (frame.temp1 != null)
{
while (skipNull && frame.temp1.atom == null)
{
frame.temp1 = frame.temp1.next;
}
var subExpression = new Atom(frame.temp1.atom, null);
var newFrame = eval.CreateFrame(
"-eval-sexp-body-",
StructureUtils.List(proc, frame.temp1.atom),
frame.context);
newFrame.function = proc;
newFrame.args = subExpression;
frame.temp1 = frame.temp1.next;
}
else
{
eval.SetReturn(null);
frame.state = new Atom("-eval-sexp-body-");
}
break;
}
}
private static void TableImport(Evaluator eval, StackFrame frame)
{
var(src, dst, names) = StructureUtils.Split3(frame.args);
if (names == null && dst.IsPair)
{
names = dst;
dst = frame.context.atom;
}
var srcCtx = GetDictionary(src);
var dstCtx = GetDictionary(dst);
string[] nameList = StructureUtils.ListToStringArray(names, "TABLE");
ContextUtils.ImportSymbols(srcCtx, dstCtx, nameList);
eval.Return(null);
}
private static void Syntax(Evaluator eval, StackFrame frame)
{
var args = frame.args;
// [tag before after]
var(tag, before, after) = StructureUtils.Split3(args.atom);
if (!tag.IsSymbol && !tag.IsString)
{
throw new ArgumentException("Tag must be string or symbol!");
}
if (!before.IsBool)
{
throw new ArgumentException("Eval args flag must be boolean!");
}
if (!after.IsBool)
{
throw new ArgumentException("Eval result flag must be boolean!");
}
Atom vars = StructureUtils.CloneTree(args?.next?.atom);
Atom body = StructureUtils.CloneTree(args?.next?.next);
if (vars.type != AtomType.Pair && vars.type != AtomType.Symbol)
{
throw new ArgumentException("Args must be list or symbol!");
}
var ctx = frame.context.value as Context;
var closure = new Closure(ctx, vars, body, (string)tag.value);
closure.EvalArgs = (bool)before.value;
closure.EvalResult = (bool)after.value;
eval.Return(new Atom(AtomType.Function, closure));
}
private static void If(Evaluator eval, StackFrame frame)
{
switch (frame.state.value)
{
case "-eval-sexp-body-":
{
// (cond BlockA BlockB)
(frame.temp1, frame.temp2, frame.temp3) = StructureUtils.Split3(frame.args);
frame.state = new Atom("-built-in-if-cond-");
}
break;
case "-built-in-if-cond-":
{
if (eval.HaveReturn())
{
var condition = eval.TakeReturn();
if (!condition.IsBool)
{
throw new ArgumentException($"Condition must return boolean atom, but found: {condition}!");
}
frame.state = new Atom((bool)condition.value ? "-built-in-if-then-" : "-built-in-if-else-");
}
else
{
eval.CreateFrame("-eval-", frame.temp1, frame.context);
}
}
break;
case "-built-in-if-then-":
{
if (frame.temp2 == null)
{
throw new ArgumentException($"If statement must have at least one block of code!");
}
if (eval.HaveReturn())
{
eval.CloseFrame();
break;
}
eval.CreateFrame("-eval-", frame.temp2, frame.context);
}
break;
case "-built-in-if-else-":
frame.state = new Atom("-eval-sexp-body-");
if (eval.HaveReturn())
{
eval.CloseFrame();
break;
}
if (frame.temp3 == null)
{
eval.Return(null);
}
else
{
eval.CreateFrame("-eval-", frame.temp3, frame.context);
}
break;
}
}