internal DynamicLet(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
Cons bindlist = (Cons)args.first;
Int32 blen = Cons.Length(bindlist);
if ((blen % 2) != 0) //odd
{
throw new Exception("Odd number of args in dynamic-let binding list");
}
binds = new BindPair[blen / 2];
for (int i = 0; i < binds.Length; i++)
{
// MEH: Better error instead of InvalidCastException
//binds[i].dvar = (DynamicVar)interpreter.analyze(bindlist.first, env,loc);
if ((binds[i].dvar = (interpreter.analyze(bindlist.first, env, loc) as DynamicVar)) == null)
{
throw new Exception("Dynamic vars must have prefix *");
}
bindlist = bindlist.rest;
binds[i].expr = interpreter.analyze(bindlist.first, env, loc);
bindlist = bindlist.rest;
}
this.body = interpreter.analyze(new Cons(interpreter.BLOCK, args.rest), env, loc);
}
internal OrExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
exprs = new IExpression[Cons.Length(args)];
for (Int32 i = 0; i < exprs.Length; i++, args = args.rest)
{
exprs[i] = interpreter.analyze(args.first, env, loc);
}
}
internal SetExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
Int32 len = Cons.Length(args);
if (len != 2)
{
throw new Exception("Wrong number of args for set");
}
var = (IVar)interpreter.analyze(args.first, env, loc);
val = interpreter.analyze(Cons.Second(args), env, loc);
}
internal ApplyExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
fexpr = interpreter.analyze(args.first, env, loc);
if (fexpr is IVar)
{
fsym = ((IVar)fexpr).getSymbol();
}
Int32 len = Cons.Length(args.rest);
argexprs = new IExpression[len];
args = args.rest;
for (Int32 i = 0; i < argexprs.Length; i++, args = args.rest)
{
argexprs[i] = interpreter.analyze(args.first, env, loc);
}
}
internal IfExpression(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
Int32 len = Cons.Length(args);
if (len < 2 || len > 3)
{
throw new Exception("Wrong number of args for if");
}
test = interpreter.analyze(args.first, env, loc);
brtrue = interpreter.analyze(Cons.Second(args), env, loc);
if (len == 3)
{
brfalse = interpreter.analyze(Cons.Third(args), env, loc);
}
else
{
brfalse = new QuoteExpr(null);
}
}
internal DynamicLet(Cons args, Env env, Interpreter interpreter, Loc loc)
{
this.loc = loc;
this.interpreter = interpreter;
Cons bindlist = (Cons)args.first;
Int32 blen = Cons.Length(bindlist);
if ((blen % 2) != 0) //odd
{
throw new Exception("Odd number of args in dynamic-let binding list");
}
binds = new BindPair[blen / 2];
for (int i = 0; i < binds.Length; i++)
{
binds[i].dvar = (DynamicVar)interpreter.analyze(bindlist.first, env, loc);
bindlist = bindlist.rest;
binds[i].expr = interpreter.analyze(bindlist.first, env, loc);
bindlist = bindlist.rest;
}
this.body = interpreter.analyze(new Cons(interpreter.BLOCK, args.rest), env, loc);
}
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));
}
}
public static Object listlength(params Object[] args)
{
Cons x = (Cons)arg(0, args);
return(Cons.Length(x));
}