public Expr Parse(ParserContext pcon, object frm)
{
ISeq form = (ISeq)frm;
// form => (let [var1 val1 var2 val2 ... ] body ... )
// or (loop [var1 val1 var2 val2 ... ] body ... )
bool isLoop = RT.first(form).Equals(Compiler.LoopSym);
if (!(RT.second(form) is IPersistentVector bindings))
{
throw new ParseException("Bad binding form, expected vector");
}
if ((bindings.count() % 2) != 0)
{
throw new ParseException("Bad binding form, expected matched symbol/value pairs.");
}
ISeq body = RT.next(RT.next(form));
if (pcon.Rhc == RHC.Eval ||
(pcon.Rhc == RHC.Expression && isLoop))
{
return(Compiler.Analyze(pcon, RT.list(RT.list(Compiler.FnOnceSym, PersistentVector.EMPTY, form)), "let__" + RT.nextID()));
}
ObjMethod method = (ObjMethod)Compiler.MethodVar.deref();
IPersistentMap backupMethodLocals = method.Locals;
IPersistentMap backupMethodIndexLocals = method.IndexLocals;
IPersistentVector recurMismatches = PersistentVector.EMPTY;
for (int i = 0; i < bindings.count() / 2; i++)
{
recurMismatches = recurMismatches.cons(false);
}
// may repeat once for each binding with a mismatch, return breaks
while (true)
{
IPersistentMap dynamicBindings = RT.map(
Compiler.LocalEnvVar, Compiler.LocalEnvVar.deref(),
Compiler.NextLocalNumVar, Compiler.NextLocalNumVar.deref());
method.SetLocals(backupMethodLocals, backupMethodIndexLocals);
if (isLoop)
{
dynamicBindings = dynamicBindings.assoc(Compiler.LoopLocalsVar, null);
}
try
{
Var.pushThreadBindings(dynamicBindings);
IPersistentVector bindingInits = PersistentVector.EMPTY;
IPersistentVector loopLocals = PersistentVector.EMPTY;
for (int i = 0; i < bindings.count(); i += 2)
{
if (!(bindings.nth(i) is Symbol))
{
throw new ParseException("Bad binding form, expected symbol, got " + bindings.nth(i));
}
Symbol sym = (Symbol)bindings.nth(i);
if (sym.Namespace != null)
{
throw new ParseException("Can't let qualified name: " + sym);
}
Expr init = Compiler.Analyze(pcon.SetRhc(RHC.Expression).SetAssign(false), bindings.nth(i + 1), sym.Name);
if (isLoop)
{
if (recurMismatches != null && RT.booleanCast(recurMismatches.nth(i / 2)))
{
HostArg ha = new HostArg(HostArg.ParameterType.Standard, init, null);
List <HostArg> has = new List <HostArg>(1)
{
ha
};
init = new StaticMethodExpr("", PersistentArrayMap.EMPTY, null, typeof(RT), "box", null, has, false);
if (RT.booleanCast(RT.WarnOnReflectionVar.deref()))
{
RT.errPrintWriter().WriteLine("Auto-boxing loop arg: " + sym);
}
}
else if (Compiler.MaybePrimitiveType(init) == typeof(int))
{
List <HostArg> args = new List <HostArg>
{
new HostArg(HostArg.ParameterType.Standard, init, null)
};
init = new StaticMethodExpr("", null, null, typeof(RT), "longCast", null, args, false);
}
else if (Compiler.MaybePrimitiveType(init) == typeof(float))
{
List <HostArg> args = new List <HostArg>
{
new HostArg(HostArg.ParameterType.Standard, init, null)
};
init = new StaticMethodExpr("", null, null, typeof(RT), "doubleCast", null, args, false);
}
}
// Sequential enhancement of env (like Lisp let*)
LocalBinding b = Compiler.RegisterLocal(sym, Compiler.TagOf(sym), init, typeof(Object), false);
BindingInit bi = new BindingInit(b, init);
bindingInits = bindingInits.cons(bi);
if (isLoop)
{
loopLocals = loopLocals.cons(b);
}
}
if (isLoop)
{
Compiler.LoopLocalsVar.set(loopLocals);
}
Expr bodyExpr;
bool moreMismatches = false;
try
{
if (isLoop)
{
object methodReturnContext = pcon.Rhc == RHC.Return ? Compiler.MethodReturnContextVar.deref() : null;
// stuff with clear paths,
Var.pushThreadBindings(RT.map(Compiler.NoRecurVar, null,
Compiler.MethodReturnContextVar, methodReturnContext));
}
bodyExpr = new BodyExpr.Parser().Parse(isLoop ? pcon.SetRhc(RHC.Return) : pcon, body);
}
finally
{
if (isLoop)
{
Var.popThreadBindings();
for (int i = 0; i < loopLocals.count(); i++)
{
LocalBinding lb = (LocalBinding)loopLocals.nth(i);
if (lb.RecurMismatch)
{
recurMismatches = (IPersistentVector)recurMismatches.assoc(i, true);
moreMismatches = true;
}
}
}
}
if (!moreMismatches)
{
return(new LetExpr(bindingInits, bodyExpr, isLoop));
}
}
finally
{
Var.popThreadBindings();
}
}
}
