static SymbolCache()
{
IF = SymbolFactory.Create("if");
SET = SymbolFactory.Create("set!");
DEFINE = SymbolFactory.Create("define");
LAMBDA = SymbolFactory.Create("lambda");
QUOTE = SymbolFactory.Create("quote");
LETREC = SymbolFactory.Create("letrec");
BEGIN = SymbolFactory.Create("begin");
AND = SymbolFactory.Create("and");
OR = SymbolFactory.Create("or");
EXPANDER = SymbolFactory.Create("_expander");
QUASIQUOTE = SymbolFactory.Create("quasiquote");
UNQUOTE = SymbolFactory.Create("unquote");
UNQUOTESPLICING = SymbolFactory.Create("unquote-splicing");
CALLWITHVALUES = SymbolFactory.Create("call-with-values");
CALLWITHCURRENTCONTINUATION =
SymbolFactory.Create("call-with-current-continuation");
CALLCC = SymbolFactory.Create("call/cc");
}
private object _Read(Token t)
{
switch (t.Type)
{
case TokenType.Boolean:
return(Boolean.Create(t.Text));
case TokenType.Character:
return(new Character(t.Text[0]));
case TokenType.EOF:
return(null);
case TokenType.Integer:
try {
return(long.Parse(t.Text));
} catch (System.FormatException) {
throw new System.Exception(
"Invalid integer format: " + t.Text
);
}
case TokenType.LeftParen:
return(ReadList());
case TokenType.Quote:
object[] quoteArr = new object[2];
quoteArr[0] = SymbolCache.QUOTE;
quoteArr[1] = Read();
return(List.Create(quoteArr));
case TokenType.Quasiquote:
object[] qquoteArr = new object[2];
qquoteArr[0] = SymbolCache.QUASIQUOTE;
qquoteArr[1] = Read();
return(List.Create(qquoteArr));
case TokenType.Unquote:
object[] unquoteArr = new object[2];
unquoteArr[0] = SymbolCache.UNQUOTE;
unquoteArr[1] = Read();
return(List.Create(unquoteArr));
case TokenType.UnquoteSplicing:
object[] unqspliceArr = new object[2];
unqspliceArr[0] = SymbolCache.UNQUOTESPLICING;
unqspliceArr[1] = Read();
return(List.Create(unqspliceArr));
case TokenType.RightParen:
throw new System.Exception("Unmatched right parenthesis.");
case TokenType.Dot:
throw new System.Exception("Unrecognized use of dot notation");
case TokenType.String:
return(t.Text);
case TokenType.Symbol:
return(SymbolFactory.Create(t.Text));
case TokenType.Vector:
Token nt = _s.NextToken();
if (nt.Type == TokenType.LeftParen)
{
return(List.ToVector((Pair)ReadList()));
}
else
{
throw new System.Exception("Invalid vector literal");
}
default:
throw new System.Exception("Unrecognized token");
}
}
