public static BacktraceException Push(Exception inner, BacktraceFrame frame, Interpreter interpreter)
{
if (inner is BacktraceException) {
((BacktraceException)inner).Frames.Add(frame);
return (BacktraceException)inner;
}
return new BacktraceException(inner, frame, interpreter);
}
public IExpression Analyze(Object expr, IEnvironment env, Location enclosingLoc)
{
Symbol symbol = expr as Symbol;
if (symbol != null) {
if (symbol.IsDynamic)
return new DynamicVar(symbol);
Object var = env.Lookup(symbol);
if (var is LocalVariable)
return new LocalVar((LocalVariable)var);
else
return new GlobalVar((Symbol)var);
}
if (!(expr is Cons)) //must be literal
return new QuoteExpr(expr);
Cons exprs = (Cons)expr;
Location loc = (Location)InnerReader.LocationTable[expr];
if (loc != null)
InnerReader.LocationTable.Remove(expr);
else
loc = enclosingLoc;
Object f = exprs.First;
Cons args = exprs.Rest;
//see if it's a macro
Symbol s = f as Symbol;
if (s != null && s.IsDefined && s.GlobalValue is Macro) {
Macro m = (Macro)s.GlobalValue;
Object[] argarray = Cons.ToVector(args);
Object mexprs = null;
try {
mexprs = m.Invoke(argarray);
} catch (Exception ex) {
BacktraceFrame frame = new BacktraceFrame(loc, s, args);
throw BacktraceException.Push(ex, frame, this);
}
try {
return Analyze(mexprs, env, loc);
} catch (Exception ex) {
BacktraceFrame frame = new BacktraceFrame(loc, "when expanding ", exprs);
throw BacktraceException.Push(ex, frame, this);
}
}
Int32 numargs = Cons.GetLength(args);
if (f == DLET)
return new DynamicLet(args, env, this, loc);
else if (f == FN)
return new Closure(args, env, this, loc);
else if (f == MACRO)
return new Macro(args, env, this, loc);
else if (f == WHILE)
return new WhileExpression(args, env, this, loc);
else if (f == BLOCK) {
if (numargs == 0)
return new QuoteExpr(null);
//remove block from block of one
else if (numargs == 1)
return Analyze(args.First, env, loc);
else
return new BlockExpression(args, env, this, loc);
} else if (f == OR) {
if (numargs == 0)
return new QuoteExpr(null);
else
return new OrExpression(args, env, this, loc);
} else if (f == IF)
return new IfExpression(args, env, this, loc);
else if (f == QUOTE)
return new QuoteExpr(args.First);
else if (f == SET)
return new SetExpression(args, env, this, loc);
else //presume funcall
return new ApplyExpression(exprs, env, this, loc);
}
//.........................................................................
public BacktraceException(Exception inner, BacktraceFrame frame, Interpreter interpreter)
: base(inner.Message, inner)
{
InnerFrames.Add(frame);
InnerInterpreter = interpreter;
}