internal BacktraceException(Exception inner,
BacktraceFrame frame,Interpreter interpreter)
: base(inner.Message,inner)
{
frames.Add(frame);
this.interpreter = interpreter;
}
internal 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);
}
internal IExpression analyze(Object expr, Env env, Loc 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;
Loc loc = (Loc)reader.locTable[expr];
if (loc != null)
reader.locTable.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.getGlobalValue() is Macro)
{
Macro m = (Macro)s.getGlobalValue();
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.Length(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);
}
