internal static void Begin(Tokenizer tokenizer, WordListBuilder wlbParent)
{
var wlbBegin = new WordListBuilder();
Evaluable evalCond = null;
while (true)
{
var word = tokenizer.NextToken().ToLower();
switch (word)
{
case "again":
wlbParent.Add(new BeginPrim(wlbBegin.Realize()));
return;
case "until":
wlbParent.Add(new BeginPrim(wlbBegin.Realize(), true));
return;
case "while":
evalCond = wlbBegin.Realize();
wlbBegin.Clear();
continue;
case "repeat" when evalCond == null:
throw new NfException("\"begin...repeat\" with no while");
case "repeat":
wlbParent.Add(new BeginPrim(wlbBegin.Realize(), false, evalCond));
return;
}
var evaluable = Interpreter.ParseWord(word);
if (evaluable == null)
{
// TODO: get more robust error handling
throw new NfException($"Couldn't locate word {word}");
}
if (evaluable.IsImmediate)
{
// Only runs at compile time so no need to supply a parent here.
evaluable.Eval(tokenizer, wlbBegin);
continue;
}
wlbBegin.Add(evaluable);
}
}
internal static void Definition(Tokenizer tokenizer)
{
var wlb = new WordListBuilder();
string currentDefWord = tokenizer.NextToken().ToLower();
Evaluable execute = null;
while (true)
{
var word = tokenizer.NextToken().ToLower();
if (word == "does>")
{
execute = wlb.Realize(true, currentDefWord);
wlb.Clear();
continue;
}
if (word == ";")
{
if (execute == null)
{
Vocabulary.CurrentVocabulary.AddDefinition(currentDefWord, wlb.Realize(true, currentDefWord));
}
else
{
var run = wlb.Realize(true, currentDefWord);
var compile = execute;
Vocabulary.CurrentVocabulary.AddDefinition(currentDefWord, new DoesWord(compile, run));
}
Session.LastDefinedWord = null;
return;
}
var evaluable = Interpreter.ParseWord(word);
if (evaluable == null)
{
// TODO: get more robust error handling
throw new NfException($"Couldn't locate word {word}");
}
if (evaluable.IsImmediate)
{
evaluable.Eval(tokenizer, wlb);
continue;
}
wlb.Add(evaluable);
}
}
internal static void Do(Tokenizer tokenizer, WordListBuilder wlbParent, bool isQuestDo)
{
var _wlbDo = new WordListBuilder();
while (true)
{
var word = tokenizer.NextToken().ToLower();
if (word == "loop")
{
wlbParent.Add(new DoPrim(_wlbDo.Realize(), false, isQuestDo));
return;
}
if (word == "+loop")
{
wlbParent.Add(new DoPrim(_wlbDo.Realize(), true, isQuestDo));
return;
}
var evaluable = Interpreter.ParseWord(word);
if (evaluable == null)
{
// TODO: get more robust error handling
throw new NfException($"Couldn't locate word {word}");
}
if (evaluable.IsImmediate)
{
evaluable.Eval(tokenizer, _wlbDo);
continue;
}
_wlbDo.Add(evaluable);
}
}
internal static void If(Tokenizer tokenizer, WordListBuilder wlbParent)
{
var wlbThenClause = new WordListBuilder();
var wlbElseClause = (WordListBuilder)null;
while (true)
{
var word = tokenizer.NextToken().ToLower();
// ReSharper disable once SwitchStatementMissingSomeCases
switch (word)
{
case "then":
wlbParent.Add(new IfPrim(wlbThenClause.Realize(), wlbElseClause?.Realize()));
return;
case "else":
wlbElseClause = wlbThenClause;
wlbThenClause = new WordListBuilder();
continue;
}
var evaluable = Interpreter.ParseWord(word);
if (evaluable == null)
{
// TODO: get more robust error handling
throw new NfException($"Couldn't locate word {word}");
}
if (evaluable.IsImmediate)
{
evaluable.Eval(tokenizer, wlbThenClause);
continue;
}
wlbThenClause.Add(evaluable);
}
}
internal static void FString(Tokenizer tokenizer, WordListBuilder wlbParent, StringType st = StringType.Forth)
{
var sbText = new StringBuilder();
var prependSpace = false;
var done = false;
// TODO: read tokenizer char by char to properly emulate white space
while (!done)
{
var word = tokenizer.NextToken();
if (word.EndsWith("\""))
{
done = true;
word = word.Substring(0, word.Length - 1);
}
if (prependSpace)
{
sbText.Append(" ");
}
prependSpace = true;
sbText.Append(word);
}
var text = sbText.ToString();
int finalValue = -1;
switch (st)
{
case StringType.Forth:
var pCountedString = Memory.Allocate(text.Length * sizeof(char) + Session.StringLengthSize);
Memory.StoreCString(pCountedString, text);
finalValue = pCountedString;
break;
case StringType.DotNet:
var index = SaveManagedObject(text);
finalValue = index;
break;
case StringType.Type:
var type = Type.GetType(text);
if (type == null)
{
throw new NfException($"Unrecognized .NET type in t\": {text}");
}
if (type.IsGenericType)
{
var genericParameterCount = type.GetGenericArguments().Length;
var parmTypes = CallAction.GetParmTypes($"Invalid types for generic type {text}", genericParameterCount);
type = type.MakeGenericType(parmTypes);
}
finalValue = SaveManagedObject(type);
break;
case StringType.Stack:
var pStackString = Memory.AllocateStackString(text.Length);
Memory.StoreString(pStackString, text);
finalValue = pStackString;
break;
}
if (wlbParent == null)
{
Stack.Push(finalValue);
if (st == StringType.Stack)
{
Stack.Push(text.Length);
}
}
else
{
wlbParent.Add(new IntPrim(finalValue));
if (st == StringType.Stack)
{
wlbParent.Add(new IntPrim(text.Length));
}
}
}