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($"Couldn't locate word {word}");
}
if (evaluable.IsImmediate)
{
evaluable.Eval(tokenizer, wlb);
continue;
}
wlb.Add(evaluable);
}
}
internal static void Begin(Tokenizer tokenizer, WordListBuilder wlbParent)
{
var wlbBegin = new WordListBuilder();
Evaluable evalCond = null;
while (true)
{
var word = tokenizer.NextToken().ToLower();
switch (word)
{
case "again":
wlbParent.Add(new BeginPrim(wlbBegin.Realize()));
return;
case "until":
wlbParent.Add(new BeginPrim(wlbBegin.Realize(), true));
return;
case "while":
evalCond = wlbBegin.Realize();
wlbBegin.Clear();
continue;
case "repeat" when evalCond == null:
throw new NfException("\"begin...repeat\" with no while");
case "repeat":
wlbParent.Add(new BeginPrim(wlbBegin.Realize(), false, evalCond));
return;
}
var evaluable = Interpreter.ParseWord(word);
if (evaluable == null)
{
// TODO: get more robust error handling
throw new NfException($"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 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);
}
}