public Interpreter()
{
this.GlobalEnv = new Environment();
this.tokenizer = new Tokenizer();
this.parser = new PairParser();
this.evaluator = new Evaluator(this);
this.macroEvaluator = new Evaluator(this);
this.macroExpander = new MacroExpander(macroEvaluator);
DefinePrimitives();
}
public override IScheminType Execute(Environment env, Evaluator eval, ScheminPair args)
{
ScheminPort readFrom = eval.CurrentInputPort;
if (args.Length > 0)
{
readFrom = (ScheminPort) args.Car;
}
Tokenizer t = new Tokenizer();
PairParser p = new PairParser();
bool completeInput = false;
bool emptyInput = true;
int openParens = 0;
int closeParens = 0;
List<Token> partialInput = new List<Token>();
while (completeInput != true)
{
StringBuilder built = new StringBuilder();
char next;
for (;;)
{
int nextRead = readFrom.InputStream.Read();
next = (char)nextRead;
if (nextRead == -1 || (next == '\n' && !emptyInput))
{
break;
}
if (next != '\r')
{
built.Append(next);
emptyInput = false;
}
}
var lineTokens = t.Tokenize(built.ToString());
foreach (Token token in lineTokens)
{
partialInput.Add(token);
if (token.Type == TokenType.OpenParen)
{
openParens++;
}
else if (token.Type == TokenType.CloseParen)
{
closeParens++;
}
}
if (openParens == closeParens)
{
completeInput = true;
break;
}
}
var parsed = p.Parse(partialInput, true).Car;
return parsed;
}