public CompileRpn(
Rpn rpn,
List <NameAndType> entityFields = null)
{
_original = rpn.Result.ToList();
var operatorEvaluator = new Dictionary <Operator, Action <ILGenerator> >
{
{ Operator.Negation, _ => _.Emit(OpCodes.Neg) },
{ Operator.Not, _ => _.Emit(OpCodes.Not) },
{ Operator.Division, _ => _.Emit(OpCodes.Div) },
{ Operator.Minus, _ => _.Emit(OpCodes.Sub) },
{ Operator.Multiplication, _ => _.Emit(OpCodes.Mul) },
{ Operator.Addition, _ => _.Emit(OpCodes.Add) }, // how to handle strings?
{ Operator.And, _ => _.Emit(OpCodes.And) },
{ Operator.Or, _ => _.Emit(OpCodes.Or) },
{ Operator.Equal, _ => _.Emit(OpCodes.Ceq) },
{ Operator.Lt, _ => _.Emit(OpCodes.Clt) },
{ Operator.Gt, _ => _.Emit(OpCodes.Cgt) },
{
Operator.NotEqual, _ =>
{
_.Emit(OpCodes.Ceq);
_.Emit(OpCodes.Ldc_I4_0);
_.Emit(OpCodes.Ceq);
}
},
{
Operator.EqGt, _ =>
{
_.Emit(OpCodes.Clt);
_.Emit(OpCodes.Ldc_I4_0);
_.Emit(OpCodes.Ceq);
}
},
{
Operator.EqLt, _ =>
{
_.Emit(OpCodes.Cgt);
_.Emit(OpCodes.Ldc_I4_0);
_.Emit(OpCodes.Ceq);
}
},
//{Operator.Question, calcQuestion},
};
_operatorEvaluator = new Action <ILGenerator> [operatorEvaluator.Keys.Max(_ => (int)_) + 1];
foreach (var p in operatorEvaluator)
{
_operatorEvaluator[(int)p.Key] = p.Value;
}
var method = new DynamicMethod("", typeof(object), new[] { typeof(object[]) }, GetType().Module);
var il = method.GetILGenerator();
var typeStack = new Stack <Type>();
foreach (var item in _original)
{
var itemNumeric = item as RpnItemOperandNumeric;
if (itemNumeric != null)
{
il.Emit(OpCodes.Ldc_R8, itemNumeric.Numeric);
typeStack.Push(typeof(double));
continue;
}
var itemOperator = item as RpnItemOperator;
if (itemOperator != null)
{
if (itemOperator.IsUnary())
{
typeStack.Pop();
}
else
{
typeStack.Pop();
typeStack.Pop();
}
operatorEvaluator[itemOperator.Operator](il);
typeStack.Push(typeof(double));
continue;
}
var itemVariable = item as RpnItemOperandVariable;
if (itemVariable != null)
{
var x = entityFields.FindIndex(_ => _.Name == itemVariable.Name);
if (x < 0)
{
throw new ArgumentException($"Unknown varable '{itemVariable.Name}'");
}
if (entityFields[x].Type != typeof(double))
{
throw new NotImplementedException();
}
else
{
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldc_I4, x);
il.Emit(OpCodes.Ldelem_Ref);
il.Emit(OpCodes.Unbox_Any, typeof(double));
}
//_original[i] = new RpnItemOperandNumeric2(() => (_variables[x] as IConvertible)?.ToDouble(null) ?? 0);
typeStack.Push(typeof(double));
continue;
}
throw new Exception("What the hell happened here?");
}
if (typeStack.Count != 1)
{
throw new Exception("What the hell happened here?");
}
il.Emit(OpCodes.Box, typeof(double));
il.Emit(OpCodes.Ret);
Evaluate = (Func <object[], object>)method.CreateDelegate(typeof(Func <object[], object>));
}
public EvaluateRpn(
Rpn rpn,
List <NameAndType> entityFields = null)
{
_functions = new Dictionary <string, FunctionDescriptor>
{
{ "min", new FunctionDescriptor(-1, funcMin, typeof(double)) },
{ "max", new FunctionDescriptor(-1, funcMax, typeof(double)) },
{ "first", new FunctionDescriptor(-1, funcFirst, typeof(string)) },
{ "str", new FunctionDescriptor(1, (stack, args) => push(stack, stack.Pop().String), typeof(string)) },
{ "val", new FunctionDescriptor(1, (stack, args) => push(stack, stack.Pop().Numeric), typeof(double)) },
{ "int", new FunctionDescriptor(1, (stack, args) => push(stack, (int)stack.Pop().Numeric), typeof(double)) },
{ "len", new FunctionDescriptor(1, (stack, args) => push(stack, stack.Pop().String?.Length), typeof(double)) },
};
_original = rpn.Result.ToList();
var operatorEvaluator = new Dictionary <Operator, Action <Stack <RpnItemOperand> > >
{
{ Operator.Negation, stack => calcUnary(stack, x => - x) },
{ Operator.Not, stack => calcUnary(stack, x => x != 0 ? 1 : 0) },
{ Operator.Division, stack => calcBinary(stack, (x, y) => x / y) },
{ Operator.Mod, stack => calcBinary(stack, (x, y) => (int)x % (int)y) },
{ Operator.Minus, stack => calcBinary(stack, (x, y) => x - y) },
{ Operator.Multiplication, stack => calcBinary(stack, (x, y) => x * y) },
{ Operator.Addition, stack => calcBinary(stack, (x, y) => x + y) },
{ Operator.Concat, concat },
{ Operator.And, stack => calcBinary(stack, (x, y) => (x != 0) && (y != 0) ? 1 : 0) },
{ Operator.Or, stack => calcBinary(stack, (x, y) => (x != 0) || (y != 0) ? 1 : 0) },
{ Operator.Question, calcQuestion },
{ Operator.NullCoalescing, calcNullCoalescing },
{
Operator.Equal, stack => calcBinary(stack, (x, y) => x == y ? 1 : 0,
(x, y) => new RpnItemOperandNumeric(string.CompareOrdinal(x, y) == 0 ? 1 : 0))
},
{
Operator.Lt, stack => calcBinary(stack, (x, y) => x < y ? 1 : 0,
(x, y) => new RpnItemOperandNumeric(string.CompareOrdinal(x, y) < 0 ? 1 : 0))
},
{
Operator.EqLt, stack => calcBinary(stack, (x, y) => x <= y ? 1 : 0,
(x, y) => new RpnItemOperandNumeric(string.CompareOrdinal(x, y) <= 0 ? 1 : 0))
},
{
Operator.Gt, stack => calcBinary(stack, (x, y) => x > y ? 1 : 0,
(x, y) => new RpnItemOperandNumeric(string.CompareOrdinal(x, y) > 0 ? 1 : 0))
},
{
Operator.EqGt, stack => calcBinary(stack, (x, y) => x >= y ? 1 : 0,
(x, y) => new RpnItemOperandNumeric(string.CompareOrdinal(x, y) >= 0 ? 1 : 0))
},
{
Operator.NotEqual, stack => calcBinary(stack, (x, y) => x != y ? 1 : 0,
(x, y) => new RpnItemOperandNumeric(string.CompareOrdinal(x, y) != 0 ? 1 : 0))
},
};
if (entityFields != null)
{
for (var i = 0; i < _original.Count; i++)
{
var itm = _original[i] as RpnItemOperandVariable;
if (itm == null)
{
continue;
}
var x = entityFields.FindIndex(_ => _.Name == itm.Name);
if (x < 0)
{
throw new ArgumentException($"Unknown varable '{itm.Name}'");
}
_original[i] = new RpnIndexedVariable(x, entityFields[x].Type);
}
}
typeEval();
for (var i = 0; i < _original.Count; i++)
{
var itmOperator = _original[i] as RpnItemOperator;
if (itmOperator != null)
{
Action <Stack <RpnItemOperand> > action = stack => operatorEvaluator[itmOperator.Operator](stack);
_original[i] = new RpnItemAction {
Action = action
};
continue;
}
var itmFunction = _original[i] as RpnItemFunction;
if (itmFunction != null)
{
var argumentCount = itmFunction.ArgumentCount;
var descriptor = _functions[itmFunction.Name];
if (descriptor.NumberOfArguments != -1 && descriptor.NumberOfArguments != argumentCount)
{
throw new ArgumentException(
$"Wrong number of arguments to '{itmFunction.Name}' function. Expected {descriptor.NumberOfArguments}, but was {argumentCount}");
}
Action <Stack <RpnItemOperand> > action = stack => descriptor.Evaluate(stack, argumentCount);
_original[i] = new RpnItemAction {
Action = action
};
continue;
}
}
}