public override void Visit(TernaryExpression expression)
{
expression.LeftExpression.Accept(this);
var test = _result;
expression.MiddleExpression.Accept(this);
var ifTrue = _result;
expression.RightExpression.Accept(this);
var ifFalse = _result;
_result = L.Expression.Condition(test, ifTrue, ifFalse);
}
private L.Expression UnwrapNullable(L.Expression expression)
{
var ti = expression.Type.GetTypeInfo();
if (ti.IsGenericType && ti.GetGenericTypeDefinition() == typeof(Nullable <>))
{
return(L.Expression.Condition(
L.Expression.Property(expression, "HasValue"),
L.Expression.Property(expression, "Value"),
L.Expression.Default(expression.Type.GetTypeInfo().GenericTypeArguments[0])));
}
return(expression);
}
public override void Visit(Identifier function)
{
if (_context == null)
{
_result = L.Expression.Constant(_parameters[function.Name]);
}
else
{
var args = new ParameterArgs();
OnEvaluateParameter(function.Name, args);
if (args.HasResult)
{
_result = L.Expression.Constant(args.Result);
return;
}
_result = L.Expression.PropertyOrField(_context, function.Name);
}
}
AlignFloatingPointTypes(
L.Expression originalTrue,
L.Expression originalFalse)
{
bool TryConvert(L.Expression from, Type to, out L.Expression converted)
{
try
{
converted = L.Expression.Convert(from, to);
return(true);
}
catch (InvalidOperationException)
{
converted = null;
return(false);
}
}
var(originalTrueType, originalFalseType) =
(originalTrue.Type, originalFalse.Type);
if (originalTrueType == originalFalseType)
{
return(originalTrue, originalFalse);
}
if (TryConvert(
originalTrue,
originalFalseType,
out var convertedTrue))
{
return(convertedTrue, originalFalse);
}
if (TryConvert(
originalFalse,
originalTrueType,
out var convertedFalse))
{
return(originalTrue, convertedFalse);
}
return(originalTrue, originalFalse);
}
public override void Visit(UnaryExpression expression)
{
expression.Expression.Accept(this);
switch (expression.Type)
{
case UnaryExpressionType.Not:
_result = L.Expression.Not(_result);
break;
case UnaryExpressionType.Negate:
_result = L.Expression.Negate(_result);
break;
case UnaryExpressionType.BitwiseNot:
_result = L.Expression.Not(_result);
break;
default:
throw new ArgumentOutOfRangeException();
}
}
private L.Expression WithCommonNumericType(L.Expression left, L.Expression right,
Func <L.Expression, L.Expression, L.Expression> action, BinaryExpressionType expressiontype = BinaryExpressionType.Unknown)
{
left = UnwrapNullable(left);
right = UnwrapNullable(right);
if (_options.HasFlag(EvaluateOptions.BooleanCalculation))
{
if (left.Type == typeof(bool))
{
left = L.Expression.Condition(left, L.Expression.Constant(1.0), L.Expression.Constant(0.0));
}
if (right.Type == typeof(bool))
{
right = L.Expression.Condition(right, L.Expression.Constant(1.0), L.Expression.Constant(0.0));
}
}
var precedence = new[]
{
typeof(decimal),
typeof(double),
typeof(float),
typeof(ulong),
typeof(long),
typeof(uint),
typeof(int),
typeof(ushort),
typeof(short),
typeof(byte),
typeof(sbyte)
};
int l = Array.IndexOf(precedence, left.Type);
int r = Array.IndexOf(precedence, right.Type);
if (l >= 0 && r >= 0)
{
var type = precedence[Math.Min(l, r)];
if (left.Type != type)
{
left = L.Expression.Convert(left, type);
}
if (right.Type != type)
{
right = L.Expression.Convert(right, type);
}
}
L.Expression comparer = null;
if (IgnoreCaseString)
{
if (Ordinal)
{
comparer = L.Expression.Property(null, typeof(StringComparer).GetProperty("OrdinalIgnoreCase"));
}
else
{
comparer = L.Expression.Property(null, typeof(StringComparer).GetProperty("CurrentCultureIgnoreCase"));
}
}
else
{
comparer = L.Expression.Property(null, typeof(StringComparer).GetProperty("Ordinal"));
}
if (comparer != null && (typeof(string).Equals(left.Type) || typeof(string).Equals(right.Type)))
{
switch (expressiontype)
{
case BinaryExpressionType.Equal: return(L.Expression.Call(comparer, typeof(StringComparer).GetRuntimeMethod("Equals", new[] { typeof(string), typeof(string) }), new L.Expression[] { left, right }));
case BinaryExpressionType.NotEqual: return(L.Expression.Not(L.Expression.Call(comparer, typeof(StringComparer).GetRuntimeMethod("Equals", new[] { typeof(string), typeof(string) }), new L.Expression[] { left, right })));
case BinaryExpressionType.GreaterOrEqual: return(L.Expression.GreaterThanOrEqual(L.Expression.Call(comparer, typeof(StringComparer).GetRuntimeMethod("Compare", new[] { typeof(string), typeof(string) }), new L.Expression[] { left, right }), L.Expression.Constant(0)));
case BinaryExpressionType.LesserOrEqual: return(L.Expression.LessThanOrEqual(L.Expression.Call(comparer, typeof(StringComparer).GetRuntimeMethod("Compare", new[] { typeof(string), typeof(string) }), new L.Expression[] { left, right }), L.Expression.Constant(0)));
case BinaryExpressionType.Greater: return(L.Expression.GreaterThan(L.Expression.Call(comparer, typeof(StringComparer).GetRuntimeMethod("Compare", new[] { typeof(string), typeof(string) }), new L.Expression[] { left, right }), L.Expression.Constant(0)));
case BinaryExpressionType.Lesser: return(L.Expression.LessThan(L.Expression.Call(comparer, typeof(StringComparer).GetRuntimeMethod("Compare", new[] { typeof(string), typeof(string) }), new L.Expression[] { left, right }), L.Expression.Constant(0)));
}
}
return(action(left, right));
}
public override void Visit(BinaryExpression expression)
{
expression.LeftExpression.Accept(this);
var left = _result;
expression.RightExpression.Accept(this);
var right = _result;
switch (expression.Type)
{
case BinaryExpressionType.And:
_result = L.Expression.AndAlso(left, right);
break;
case BinaryExpressionType.Or:
_result = L.Expression.OrElse(left, right);
break;
case BinaryExpressionType.NotEqual:
_result = WithCommonNumericType(left, right, L.Expression.NotEqual, expression.Type);
break;
case BinaryExpressionType.LesserOrEqual:
_result = WithCommonNumericType(left, right, L.Expression.LessThanOrEqual, expression.Type);
break;
case BinaryExpressionType.GreaterOrEqual:
_result = WithCommonNumericType(left, right, L.Expression.GreaterThanOrEqual, expression.Type);
break;
case BinaryExpressionType.Lesser:
_result = WithCommonNumericType(left, right, L.Expression.LessThan, expression.Type);
break;
case BinaryExpressionType.Greater:
_result = WithCommonNumericType(left, right, L.Expression.GreaterThan, expression.Type);
break;
case BinaryExpressionType.Equal:
_result = WithCommonNumericType(left, right, L.Expression.Equal, expression.Type);
break;
case BinaryExpressionType.Minus:
if (Checked)
{
_result = WithCommonNumericType(left, right, L.Expression.SubtractChecked);
}
else
{
_result = WithCommonNumericType(left, right, L.Expression.Subtract);
}
break;
case BinaryExpressionType.Plus:
if (Checked)
{
_result = WithCommonNumericType(left, right, L.Expression.AddChecked);
}
else
{
_result = WithCommonNumericType(left, right, L.Expression.Add);
}
break;
case BinaryExpressionType.Modulo:
_result = WithCommonNumericType(left, right, L.Expression.Modulo);
break;
case BinaryExpressionType.Div:
_result = WithCommonNumericType(left, right, L.Expression.Divide);
break;
case BinaryExpressionType.Times:
if (Checked)
{
_result = WithCommonNumericType(left, right, L.Expression.MultiplyChecked);
}
else
{
_result = WithCommonNumericType(left, right, L.Expression.Multiply);
}
break;
case BinaryExpressionType.BitwiseOr:
_result = L.Expression.Or(left, right);
break;
case BinaryExpressionType.BitwiseAnd:
_result = L.Expression.And(left, right);
break;
case BinaryExpressionType.BitwiseXOr:
_result = L.Expression.ExclusiveOr(left, right);
break;
case BinaryExpressionType.LeftShift:
_result = L.Expression.LeftShift(left, right);
break;
case BinaryExpressionType.RightShift:
_result = L.Expression.RightShift(left, right);
break;
default:
throw new ArgumentOutOfRangeException();
}
}
private L.Expression[] PrepareMethodArgumentsIfValid(ParameterInfo[] parameters, L.Expression[] arguments)
{
if (!parameters.Any() && !arguments.Any())
{
return(arguments);
}
if (!parameters.Any())
{
return(null);
}
bool paramsMatchArguments = true;
var lastParameter = parameters.Last();
bool hasParamsKeyword = lastParameter.IsDefined(typeof(ParamArrayAttribute));
if (hasParamsKeyword && parameters.Length > arguments.Length)
{
return(null);
}
L.Expression[] newArguments = new L.Expression[parameters.Length];
L.Expression[] paramsKeywordArgument = null;
Type paramsElementType = null;
int paramsParameterPosition = 0;
if (!hasParamsKeyword)
{
paramsMatchArguments &= parameters.Length == arguments.Length;
if (!paramsMatchArguments)
{
return(null);
}
}
else
{
paramsParameterPosition = lastParameter.Position;
paramsElementType = lastParameter.ParameterType.GetElementType();
paramsKeywordArgument = new L.Expression[arguments.Length - parameters.Length + 1];
}
for (int i = 0; i < arguments.Length; i++)
{
var isParamsElement = hasParamsKeyword && i >= paramsParameterPosition;
var argumentType = arguments[i].Type;
var parameterType = isParamsElement ? paramsElementType : parameters[i].ParameterType;
paramsMatchArguments &= argumentType == parameterType;
if (!paramsMatchArguments)
{
return(null);
}
if (!isParamsElement)
{
newArguments[i] = arguments[i];
}
else
{
paramsKeywordArgument[i - paramsParameterPosition] = arguments[i];
}
}
if (hasParamsKeyword)
{
newArguments[paramsParameterPosition] = L.Expression.NewArrayInit(paramsElementType, paramsKeywordArgument);
}
return(newArguments);
}
public LambdaExpressionVistor(L.ParameterExpression context, EvaluateOptions options)
{
_context = context;
_options = options;
}
public override void Visit(Function function)
{
var functionArgs = new FunctionArgs
{
Parameters = new Expression[function.Expressions.Length]
};
// Don't call parameters right now, instead let the function do it as needed.
// Some parameters shouldn't be called, for instance, in a if(), the "not" value might be a division by zero
// Evaluating every value could produce unexpected behaviour
for (int i = 0; i < function.Expressions.Length; i++)
{
functionArgs.Parameters[i] = new Expression(function.Expressions[i], _options);
functionArgs.Parameters[i].EvaluateFunction += EvaluateFunction;
functionArgs.Parameters[i].EvaluateParameter += EvaluateParameter;
// Assign the parameters of the Expression to the arguments so that custom Functions and Parameters can use them
functionArgs.Parameters[i].Parameters = Parameters;
}
OnEvaluateFunction(IgnoreCaseString ? function.Identifier.Name.ToLower() : function.Identifier.Name, functionArgs);
var args = new L.Expression[function.Expressions.Length];
for (int i = 0; i < function.Expressions.Length; i++)
{
function.Expressions[i].Accept(this);
args[i] = _result;
}
switch (function.Identifier.Name.ToLowerInvariant())
{
case "abs":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Abs() takes exactly 1 argument");
}
var useDouble = _options.HasFlag(
EvaluateOptions.UseDoubleForAbsFunction);
MethodInfo absMethod;
L.Expression absArg0;
if (useDouble)
{
absMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Abs),
new[] { typeof(double) });
absArg0 = L.Expression.Convert(args[0], typeof(double));
}
else
{
absMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Abs),
new[] { typeof(decimal) });
absArg0 = L.Expression.Convert(args[0], typeof(decimal));
}
_result = L.Expression.Call(absMethod, absArg0);
break;
case "acos":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Acos() takes exactly 1 argument");
}
var acosMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Acos),
new[] { typeof(double) });
var acosArg0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(acosMethod, acosArg0);
break;
case "asin":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Asin() takes exactly 1 argument");
}
var asinMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Asin),
new[] { typeof(double) });
var asinArg0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(asinMethod, asinArg0);
break;
case "atan":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Atan() takes exactly 1 argument");
}
var atanMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Atan),
new[] { typeof(double) });
var atanArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(atanMethod, atanArgs0);
break;
case "ceiling":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Ceiling() takes exactly 1 argument");
}
var ceilingMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Ceiling),
new[] { typeof(double) });
var ceilingArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(ceilingMethod, ceilingArgs0);
break;
case "cos":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Cos() takes exactly 1 argument");
}
var cosMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Cos),
new[] { typeof(double) });
var cosArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(cosMethod, cosArgs0);
break;
case "exp":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Exp() takes exactly 1 argument");
}
var expMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Exp),
new[] { typeof(double) });
var expArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(expMethod, expArgs0);
break;
case "floor":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Floor() takes exactly 1 argument");
}
var floorMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Floor),
new[] { typeof(double) });
var floorArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(floorMethod, floorArgs0);
break;
case "ieeeremainder":
if (function.Expressions.Length != 2)
{
throw new ArgumentException("IEEEReaminer() takes exactly 2 arguments");
}
var ieeeMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.IEEERemainder),
new[] { typeof(double), typeof(double) });
var ieeeMethodArgs0 = L.Expression.Convert(
args[0],
typeof(double));
var ieeeMethodArgs1 = L.Expression.Convert(
args[1],
typeof(double));
_result = L.Expression.Call(ieeeMethod, ieeeMethodArgs0, ieeeMethodArgs1);
break;
case "log":
if (function.Expressions.Length != 2)
{
throw new ArgumentException("Log() takes exactly 2 arguments");
}
var logMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Log),
new[] { typeof(double), typeof(double) });
var logMethodArgs0 = L.Expression.Convert(
args[0],
typeof(double));
var logMethodArgs1 = L.Expression.Convert(
args[1],
typeof(double));
_result = L.Expression.Call(logMethod, logMethodArgs0, logMethodArgs1);
break;
case "log10":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Log10() takes exactly 1 argument");
}
var log10Method = typeof(Math).GetRuntimeMethod(
nameof(Math.Log10),
new[] { typeof(double) });
var log10Args0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(log10Method, log10Args0);
break;
case "round":
var roundParameterCount = function.Expressions.Length;
if (roundParameterCount == 0 || roundParameterCount > 2)
{
throw new ArgumentException("Round() takes exactly 1 or 2 arguments");
}
var rounding =
_options.HasFlag(EvaluateOptions.RoundAwayFromZero)
? MidpointRounding.AwayFromZero
: MidpointRounding.ToEven;
if (roundParameterCount == 1)
{
var roundMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Round),
new[]
{
typeof(double),
typeof(MidpointRounding)
});
var roundMethodArg0 = L.Expression.Convert(
args[0],
typeof(double));
_result = L.Expression.Call(
roundMethod,
roundMethodArg0,
L.Expression.Constant(rounding));
}
else
{
var roundMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Round),
new[]
{
typeof(double), typeof(int),
typeof(MidpointRounding)
});
var roundMethodArg0 = L.Expression.Convert(
args[0],
typeof(double));
var roundMethodArg1 = L.Expression.Convert(
args[1],
typeof(int));
_result = L.Expression.Call(
roundMethod,
roundMethodArg0,
roundMethodArg1,
L.Expression.Constant(rounding));
}
break;
case "sign":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Sign() takes exactly 1 argument");
}
var signMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Sign),
new[] { typeof(double) });
var signArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(signMethod, signArgs0);
break;
case "sin":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Sin() takes exactly 1 argument");
}
var sinMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Sin),
new[] { typeof(double) });
var sinArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(sinMethod, sinArgs0);
break;
case "sqrt":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Sqrt() takes exactly 1 argument");
}
var sqrtMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Sqrt),
new[] { typeof(double) });
var sqrtArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(sqrtMethod, sqrtArgs0);
break;
case "tan":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Tan() takes exactly 1 argument");
}
var tanMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Tan),
new[] { typeof(double) });
var tanArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(tanMethod, tanArgs0);
break;
case "truncate":
if (function.Expressions.Length != 1)
{
throw new ArgumentException("Truncate() takes exactly 1 argument");
}
var truncateMethod = typeof(Math).GetRuntimeMethod(
nameof(Math.Truncate),
new[] { typeof(double) });
var truncateArgs0 = L.Expression.Convert(args[0], typeof(double));
_result = L.Expression.Call(truncateMethod, truncateArgs0);
break;
case "if":
if (args[0].Type != typeof(bool))
{
throw new ArgumentException("if statement must have a boolean condition to process");
}
var(args1, args2) = AlignFloatingPointTypes(args[1], args[2]);
_result = L.Expression.Condition(args[0], args1, args2);
break;
case "in":
var items = L.Expression.NewArrayInit(args[0].Type,
new ArraySegment <L.Expression>(args, 1, args.Length - 1).ToArray());
var smi = typeof(Array).GetRuntimeMethod("IndexOf", new[] { typeof(Array), typeof(object) });
var r = L.Expression.Call(smi, L.Expression.Convert(items, typeof(Array)), L.Expression.Convert(args[0], typeof(object)));
_result = L.Expression.GreaterThanOrEqual(r, L.Expression.Constant(0));
break;
case "min":
var min_arg0 = L.Expression.Convert(args[0], typeof(double));
var min_arg1 = L.Expression.Convert(args[1], typeof(double));
_result = L.Expression.Condition(L.Expression.LessThan(min_arg0, min_arg1), min_arg0, min_arg1);
break;
case "max":
var max_arg0 = L.Expression.Convert(args[0], typeof(double));
var max_arg1 = L.Expression.Convert(args[1], typeof(double));
_result = L.Expression.Condition(L.Expression.GreaterThan(max_arg0, max_arg1), max_arg0, max_arg1);
break;
case "pow":
var pow_arg0 = L.Expression.Convert(args[0], typeof(double));
var pow_arg1 = L.Expression.Convert(args[1], typeof(double));
_result = L.Expression.Power(pow_arg0, pow_arg1);
break;
default:
if (functionArgs.HasResult)
{
_result = L.Expression.Constant(functionArgs.Result);
break;
}
var mi = FindMethod(function.Identifier.Name, args);
_result = L.Expression.Call(_context, mi.BaseMethodInfo, mi.PreparedArguments);
break;
}
}
public override void Visit(ValueExpression expression)
{
_result = L.Expression.Constant(expression.Value);
}