public static object CompileQuasiQuote(int level, object arg, Environment environment)
{
if (level == 0)
{
return(Compile1(arg, environment));
}
if (arg is ISequence)
{
ISequence c = (ISequence)arg;
if (c.First() == UNQUOTE)
{
return(new Pair(UNQUOTE, new Pair(CompileQuasiQuote(level - 1, Runtime.Car(Runtime.Cdr(arg)), environment))));
}
if ((level == 1) && (c.First() == UNQUOTE_SPLICING))
{
return(new Pair(UNQUOTE_SPLICING, new Pair(CompileQuasiQuote(level - 1, Runtime.Car(Runtime.Cdr(arg)), environment))));
}
if (c.First() == QUASIQUOTE)
{
return(new Pair(QUASIQUOTE, new Pair(CompileQuasiQuote(level + 1, Runtime.Car(Runtime.Cdr(arg)), environment))));
}
Pair r = null;
foreach (object o in c)
{
r = new Pair(CompileQuasiQuote(level, o, environment), r);
}
return(r.Reverse());
}
return(arg);
}
public static Expression Compile1(Object s, Environment environment)
{
// Literals are constants
if (Runtime.IsLiteral(s))
{
return(Expression.Constant(s));
}
// Special Syntax gets expanded and compiled
if (Runtime.IsSsyntax(s))
{
return(Compile1(Runtime.ExpandSSyntax(s), environment));
}
// Symbols are variable references
if (s is Symbol)
{
return(CompileVarRef((Symbol)s));
}
// Special Syntax gets expanded and compiled
if (Runtime.IsSsyntax(Runtime.Car(s)))
{
object expansion = Runtime.ExpandSSyntax(((Pair)s).First());
return(Compile1(new Pair(expansion, (Pair)s), environment));
}
if (s is Pair)
{
object f = ((Pair)s).First();
// Special Forms
if (f == Symbol.FromName("if"))
{
return(Compiler.CompileIf(((Pair)s).Rest(), environment));
}
if (f == Symbol.FromName("quote"))
{
return(Compiler.CompileQuote(((Pair)s).Rest(), environment));
}
if (f == Symbol.FromName("call-clr"))
{
return(Compiler.CompileCall((Pair)((Pair)s).Rest(), environment));
}
if (f == Symbol.FromName("call-instance"))
{
return(Compiler.CompileInstanceCall((Pair)((Pair)s).Rest(), environment));
}
if (f == Symbol.FromName("fn"))
{
return(Compiler.CompileFn((Pair)((Pair)s).Rest(), environment));
}
if (f == Symbol.FromName("macro"))
{
return(Compiler.CompileMac((Pair)((Pair)s).Rest(), environment));
}
if (f == Symbol.FromName("quasiquote"))
{
return(Compiler.CompileQuasiQuote((Pair)((Pair)s).Rest(), environment));
}
if ((f is Symbol) && (environment.Contains((Symbol)f)))
{
object value = environment.GetValue((Symbol)f);
// Macros get invoked at compile time, then their results are themeselves compiled
if (value is Macro)
{
object expansion = ((Macro)value).Call(Runtime.AsArray(((Pair)s).Rest()));
return(Compile1(expansion, environment));
}
}
// It must be a function call
return(CompileFunctionCall(f, ((Pair)s).Rest(), environment));
}
throw new LSharpException(string.Format("Bad object in expression: ", s), environment);
}