//
// Expression.cs
//
// Author:
// Jb Evain (jbevain@novell.com)
// Miguel de Icaza (miguel@novell.com)
//
// (C) 2008 Novell, Inc. (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Globalization;
using System.Linq;
using System.Reflection;
using System.Reflection.Emit;
namespace System.Linq.Expressions{
public abstract class Expression {
ExpressionType node_type;
Type type;
internal const BindingFlags PublicInstance = BindingFlags.Public | BindingFlags.Instance | BindingFlags.FlattenHierarchy;
internal const BindingFlags NonPublicInstance = BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.FlattenHierarchy;
internal const BindingFlags PublicStatic = BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy;
internal const BindingFlags AllInstance = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.FlattenHierarchy;
internal const BindingFlags AllStatic = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static | BindingFlags.FlattenHierarchy;
internal const BindingFlags All = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static | BindingFlags.Instance | BindingFlags.FlattenHierarchy;
public ExpressionType NodeType {
get { return node_type; }
}
public Type Type {
get { return type; }
}
protected Expression (ExpressionType node_type, Type type)
{
this.node_type = node_type;
this.type = type;
}
public override string ToString ()
{
return ExpressionPrinter.ToString (this);
}
#region Binary Expressions
static MethodInfo GetUnaryOperator (string oper_name, Type declaring, Type param)
{
return GetUnaryOperator (oper_name, declaring, param, null);
}
static MethodInfo GetUnaryOperator (string oper_name, Type declaring, Type param, Type ret)
{
var methods = declaring.GetNotNullableType ().GetMethods (PublicStatic);
foreach (var method in methods) {
if (method.Name != oper_name)
continue;
var parameters = method.GetParameters ();
if (parameters.Length != 1)
continue;
if (method.IsGenericMethod)
continue;
if (!IsAssignableToParameterType (param.GetNotNullableType (), parameters [0]))
continue;
if (ret != null && method.ReturnType != ret.GetNotNullableType ())
continue;
return method;
}
return null;
}
internal static MethodInfo GetTrueOperator (Type self)
{
return GetBooleanOperator ("op_True", self);
}
internal static MethodInfo GetFalseOperator (Type self)
{
return GetBooleanOperator ("op_False", self);
}
static MethodInfo GetBooleanOperator (string op, Type self)
{
return GetUnaryOperator (op, self, self, typeof (bool));
}
static bool IsAssignableToParameterType (Type type, ParameterInfo param)
{
var ptype = param.ParameterType;
if (ptype.IsByRef)
ptype = ptype.GetElementType ();
return type.GetNotNullableType ().IsAssignableTo (ptype);
}
static MethodInfo CheckUnaryMethod (MethodInfo method, Type param)
{
if (method.ReturnType == typeof (void))
throw new ArgumentException ("Specified method must return a value", "method");
if (!method.IsStatic)
throw new ArgumentException ("Method must be static", "method");
var parameters = method.GetParameters ();
if (parameters.Length != 1)
throw new ArgumentException ("Must have only one parameters", "method");
if (!IsAssignableToParameterType (param.GetNotNullableType (), parameters [0]))
throw new InvalidOperationException ("left-side argument type does not match expression type");
return method;
}
static MethodInfo UnaryCoreCheck (string oper_name, Expression expression, MethodInfo method, Func<Type, bool> validator)
{
if (expression == null)
throw new ArgumentNullException ("expression");
if (method != null)
return CheckUnaryMethod (method, expression.Type);
var type = expression.Type.GetNotNullableType ();
if (validator (type))
return null;
if (oper_name != null) {
method = GetUnaryOperator (oper_name, type, expression.Type);
if (method != null)
return method;
}
throw new InvalidOperationException (
string.Format ("Operation {0} not defined for {1}", oper_name != null ? oper_name.Substring (3) : "is", expression.Type));
}
static MethodInfo GetBinaryOperator (string oper_name, Type on_type, Expression left, Expression right)
{
MethodInfo [] methods = on_type.GetMethods (PublicStatic);
foreach (var method in methods) {
if (method.Name != oper_name)
continue;
var parameters = method.GetParameters ();
if (parameters.Length != 2)
continue;
if (method.IsGenericMethod)
continue;
if (!IsAssignableToParameterType (left.Type, parameters [0]))
continue;
if (!IsAssignableToParameterType (right.Type, parameters [1]))
continue;
// Method has papers in order.
return method;
}
return null;
}
//
// Performs basic checks on the incoming expressions for binary expressions
// and any provided MethodInfo.
//
static MethodInfo BinaryCoreCheck (string oper_name, Expression left, Expression right, MethodInfo method)
{
if (left == null)
throw new ArgumentNullException ("left");
if (right == null)
throw new ArgumentNullException ("right");
if (method != null){
if (method.ReturnType == typeof (void))
throw new ArgumentException ("Specified method must return a value", "method");
if (!method.IsStatic)
throw new ArgumentException ("Method must be static", "method");
var parameters = method.GetParameters ();
if (parameters.Length != 2)
throw new ArgumentException ("Must have only two parameters", "method");
if (!IsAssignableToParameterType (left.Type, parameters [0]))
throw new InvalidOperationException ("left-side argument type does not match left expression type");
if (!IsAssignableToParameterType (right.Type, parameters [1]))
throw new InvalidOperationException ("right-side argument type does not match right expression type");
return method;
} else {
Type ltype = left.Type;
Type rtype = right.Type;
Type ultype = ltype.GetNotNullableType ();
Type urtype = rtype.GetNotNullableType ();
if (oper_name == "op_BitwiseOr" || oper_name == "op_BitwiseAnd") {
if (ultype == typeof (bool)) {
if (ultype == urtype && ltype == rtype)
return null;
}
}
// Use IsNumber to avoid expensive reflection.
if (IsNumber (ultype)) {
if (ultype == urtype && ltype == rtype)
return null;
if (oper_name != null){
method = GetBinaryOperator (oper_name, urtype, left, right);
if (method != null)
return method;
}
}
if (oper_name != null){
method = GetBinaryOperator (oper_name, ultype, left, right);
if (method != null)
return method;
}
if (oper_name == "op_Equality" || oper_name == "op_Inequality") {
//
// == and != allow reference types without operators defined.
//
if (!ltype.IsValueType && !rtype.IsValueType)
return null;
if (ltype == rtype && ultype.IsEnum)
return null;
if (ltype == rtype && ultype == typeof (bool))
return null;
}
if (oper_name == "op_LeftShift" || oper_name == "op_RightShift") {
if (IsInt (ultype) && urtype == typeof (int))
return null;
}
throw new InvalidOperationException (
String.Format ("Operation {0} not defined for {1} and {2}", oper_name != null ? oper_name.Substring (3) : "is", ltype, rtype));
}
}
//
// This is like BinaryCoreCheck, but if no method is used adds the restriction that
// only ints and bools are allowed
//
static MethodInfo BinaryBitwiseCoreCheck (string oper_name, Expression left, Expression right, MethodInfo method)
{
if (left == null)
throw new ArgumentNullException ("left");
if (right == null)
throw new ArgumentNullException ("right");
if (method == null) {
// avoid reflection shortcut and catches Ints/bools before we check Numbers in general
if (left.Type == right.Type && IsIntOrBool (left.Type))
return null;
}
method = BinaryCoreCheck (oper_name, left, right, method);
if (method == null) {
// The check in BinaryCoreCheck allows a bit more than we do
// (floats and doubles). Catch this here
if (left.Type == typeof (double) || left.Type == typeof (float))
throw new InvalidOperationException ("Types not supported");
}
return method;
}
static BinaryExpression MakeSimpleBinary (ExpressionType et, Expression left, Expression right, MethodInfo method)
{
bool is_lifted;
Type type;
if (method == null) {
is_lifted = left.Type.IsNullable ();
type = left.Type;
} else {
var parameters = method.GetParameters ();
var lp = parameters [0];
var rp = parameters [1];
if (IsAssignableToOperatorParameter (left, lp) && IsAssignableToOperatorParameter (right, rp)) {
is_lifted = false;
type = method.ReturnType;
} else if (left.Type.IsNullable ()
&& right.Type.IsNullable ()
&& left.Type.GetNotNullableType () == lp.ParameterType
&& right.Type.GetNotNullableType () == rp.ParameterType
&& !method.ReturnType.IsNullable ()) {
is_lifted = true;
type = method.ReturnType.MakeNullableType ();
} else
throw new InvalidOperationException ();
}
return new BinaryExpression (et, type, left, right, is_lifted, is_lifted, method, null);
}
static bool IsAssignableToOperatorParameter (Expression expression, ParameterInfo parameter)
{
if (expression.Type == parameter.ParameterType)
return true;
if ((!expression.Type.IsNullable () && !parameter.ParameterType.IsNullable ())
&& IsAssignableToParameterType (expression.Type, parameter))
return true;
return false;
}
static UnaryExpression MakeSimpleUnary (ExpressionType et, Expression expression, MethodInfo method)
{
bool is_lifted;
Type type;
if (method == null) {
type = expression.Type;
is_lifted = type.IsNullable ();
} else {
var parameter = method.GetParameters () [0];
if (IsAssignableToOperatorParameter (expression, parameter)) {
is_lifted = false;
type = method.ReturnType;
} else if (expression.Type.IsNullable ()
&& expression.Type.GetNotNullableType () == parameter.ParameterType
&& !method.ReturnType.IsNullable ()) {
is_lifted = true;
type = method.ReturnType.MakeNullableType ();
} else
throw new InvalidOperationException ();
}
return new UnaryExpression (et, expression, type, method, is_lifted);
}
static BinaryExpression MakeBoolBinary (ExpressionType et, Expression left, Expression right, bool liftToNull, MethodInfo method)
{
bool is_lifted;
Type type;
if (method == null) {
if (!left.Type.IsNullable () && !right.Type.IsNullable ()) {
is_lifted = false;
liftToNull = false;
type = typeof (bool);
} else if (left.Type.IsNullable () && right.Type.IsNullable ()) {
is_lifted = true;
type = liftToNull ? typeof (bool?) : typeof (bool);
} else
throw new InvalidOperationException ();
} else {
var parameters = method.GetParameters ();
var lp = parameters [0];
var rp = parameters [1];
if (IsAssignableToOperatorParameter (left, lp) && IsAssignableToOperatorParameter (right, rp)) {
is_lifted = false;
liftToNull = false;
type = method.ReturnType;
} else if (left.Type.IsNullable ()
&& right.Type.IsNullable ()
&& left.Type.GetNotNullableType () == lp.ParameterType
&& right.Type.GetNotNullableType () == rp.ParameterType) {
is_lifted = true;
if (method.ReturnType == typeof (bool))
type = liftToNull ? typeof (bool?) : typeof (bool);
else if (!method.ReturnType.IsNullable ()) {
//
// This behavior is not documented: what
// happens if the result is not typeof(bool), but
// the parameters are nullable: the result
// becomes nullable<returntype>
//
// See:
// https://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=323139
type = method.ReturnType.MakeNullableType ();
} else
throw new InvalidOperationException ();
} else
throw new InvalidOperationException ();
}
return new BinaryExpression (et, type, left, right, liftToNull, is_lifted, method, null);
}
//
// Arithmetic
//
public static BinaryExpression Add (Expression left, Expression right)
{
return Add (left, right, null);
}
public static BinaryExpression Add (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_Addition", left, right, method);
return MakeSimpleBinary (ExpressionType.Add, left, right, method);
}
public static BinaryExpression AddChecked (Expression left, Expression right)
{
return AddChecked (left, right, null);
}
public static BinaryExpression AddChecked (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_Addition", left, right, method);
// The check in BinaryCoreCheck allows a bit more than we do
// (byte, sbyte). Catch that here
if (method == null) {
if (left.Type == typeof (byte) || left.Type == typeof (sbyte))
throw new InvalidOperationException (String.Format ("AddChecked not defined for {0} and {1}", left.Type, right.Type));
}
return MakeSimpleBinary (ExpressionType.AddChecked, left, right, method);
}
public static BinaryExpression Subtract (Expression left, Expression right)
{
return Subtract (left, right, null);
}
public static BinaryExpression Subtract (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_Subtraction", left, right, method);
return MakeSimpleBinary (ExpressionType.Subtract, left, right, method);
}
public static BinaryExpression SubtractChecked (Expression left, Expression right)
{
return SubtractChecked (left, right, null);
}
public static BinaryExpression SubtractChecked (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_Subtraction", left, right, method);
// The check in BinaryCoreCheck allows a bit more than we do
// (byte, sbyte). Catch that here
if (method == null) {
if (left.Type == typeof (byte) || left.Type == typeof (sbyte))
throw new InvalidOperationException (String.Format ("SubtractChecked not defined for {0} and {1}", left.Type, right.Type));
}
return MakeSimpleBinary (ExpressionType.SubtractChecked, left, right, method);
}
public static BinaryExpression Modulo (Expression left, Expression right)
{
return Modulo (left, right, null);
}
public static BinaryExpression Modulo (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_Modulus", left, right, method);
return MakeSimpleBinary (ExpressionType.Modulo, left, right, method);
}
public static BinaryExpression Multiply (Expression left, Expression right)
{
return Multiply (left, right, null);
}
public static BinaryExpression Multiply (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_Multiply", left, right, method);
return MakeSimpleBinary (ExpressionType.Multiply, left, right, method);
}
public static BinaryExpression MultiplyChecked (Expression left, Expression right)
{
return MultiplyChecked (left, right, null);
}
public static BinaryExpression MultiplyChecked (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_Multiply", left, right, method);
return MakeSimpleBinary (ExpressionType.MultiplyChecked, left, right, method);
}
public static BinaryExpression Divide (Expression left, Expression right)
{
return Divide (left, right, null);
}
public static BinaryExpression Divide (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_Division", left, right, method);
return MakeSimpleBinary (ExpressionType.Divide, left, right, method);
}
public static BinaryExpression Power (Expression left, Expression right)
{
return Power (left, right, null);
}
public static BinaryExpression Power (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck (null, left, right, method);
if (left.Type.GetNotNullableType () != typeof (double))
throw new InvalidOperationException ("Power only supports double arguments");
return MakeSimpleBinary (ExpressionType.Power, left, right, method);
}
//
// Bitwise
//
public static BinaryExpression And (Expression left, Expression right)
{
return And (left, right, null);
}
public static BinaryExpression And (Expression left, Expression right, MethodInfo method)
{
method = BinaryBitwiseCoreCheck ("op_BitwiseAnd", left, right, method);
return MakeSimpleBinary (ExpressionType.And, left, right, method);
}
public static BinaryExpression Or (Expression left, Expression right)
{
return Or (left, right, null);
}
public static BinaryExpression Or (Expression left, Expression right, MethodInfo method)
{
method = BinaryBitwiseCoreCheck ("op_BitwiseOr", left, right, method);
return MakeSimpleBinary (ExpressionType.Or, left, right, method);
}
public static BinaryExpression ExclusiveOr (Expression left, Expression right)
{
return ExclusiveOr (left, right, null);
}
public static BinaryExpression ExclusiveOr (Expression left, Expression right, MethodInfo method)
{
method = BinaryBitwiseCoreCheck ("op_ExclusiveOr", left, right, method);
return MakeSimpleBinary (ExpressionType.ExclusiveOr, left, right, method);
}
public static BinaryExpression LeftShift (Expression left, Expression right)
{
return LeftShift (left, right, null);
}
public static BinaryExpression LeftShift (Expression left, Expression right, MethodInfo method)
{
method = BinaryBitwiseCoreCheck ("op_LeftShift", left, right, method);
return MakeSimpleBinary (ExpressionType.LeftShift, left, right, method);
}
public static BinaryExpression RightShift (Expression left, Expression right)
{
return RightShift (left, right, null);
}
public static BinaryExpression RightShift (Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck ("op_RightShift", left, right, method);
return MakeSimpleBinary (ExpressionType.RightShift, left, right, method);
}
//
// Short-circuit
//
public static BinaryExpression AndAlso (Expression left, Expression right)
{
return AndAlso (left, right, null);
}
public static BinaryExpression AndAlso (Expression left, Expression right, MethodInfo method)
{
method = ConditionalBinaryCheck ("op_BitwiseAnd", left, right, method);
return MakeBoolBinary (ExpressionType.AndAlso, left, right, true, method);
}
static MethodInfo ConditionalBinaryCheck (string oper, Expression left, Expression right, MethodInfo method)
{
method = BinaryCoreCheck (oper, left, right, method);
if (method == null) {
if (left.Type.GetNotNullableType () != typeof (bool))
throw new InvalidOperationException ("Only booleans are allowed");
} else {
var type = left.Type.GetNotNullableType ();
// The method should have identical parameter and return types.
if (left.Type != right.Type || method.ReturnType != type)
throw new ArgumentException ("left, right and return type must match");
var optrue = GetTrueOperator (type);
var opfalse = GetFalseOperator (type);
if (optrue == null || opfalse == null)
throw new ArgumentException ("Operators true and false are required but not defined");
}
return method;
}
public static BinaryExpression OrElse (Expression left, Expression right)
{
return OrElse (left, right, null);
}
public static BinaryExpression OrElse (Expression left, Expression right, MethodInfo method)
{
method = ConditionalBinaryCheck ("op_BitwiseOr", left, right, method);
return MakeBoolBinary (ExpressionType.OrElse, left, right, true, method);
}
//
// Comparison
//
public static BinaryExpression Equal (Expression left, Expression right)
{
return Equal (left, right, false, null);
}
public static BinaryExpression Equal (Expression left, Expression right, bool liftToNull, MethodInfo method)
{
method = BinaryCoreCheck ("op_Equality", left, right, method);
return MakeBoolBinary (ExpressionType.Equal, left, right, liftToNull, method);
}
public static BinaryExpression NotEqual (Expression left, Expression right)
{
return NotEqual (left, right, false, null);
}
public static BinaryExpression NotEqual (Expression left, Expression right, bool liftToNull, MethodInfo method)
{
method = BinaryCoreCheck ("op_Inequality", left, right, method);
return MakeBoolBinary (ExpressionType.NotEqual, left, right, liftToNull, method);
}
public static BinaryExpression GreaterThan (Expression left, Expression right)
{
return GreaterThan (left, right, false, null);
}
public static BinaryExpression GreaterThan (Expression left, Expression right, bool liftToNull, MethodInfo method)
{
method = BinaryCoreCheck ("op_GreaterThan", left, right, method);
return MakeBoolBinary (ExpressionType.GreaterThan, left, right, liftToNull, method);
}
public static BinaryExpression GreaterThanOrEqual (Expression left, Expression right)
{
return GreaterThanOrEqual (left, right, false, null);
}
public static BinaryExpression GreaterThanOrEqual (Expression left, Expression right, bool liftToNull, MethodInfo method)
{
method = BinaryCoreCheck ("op_GreaterThanOrEqual", left, right, method);
return MakeBoolBinary (ExpressionType.GreaterThanOrEqual, left, right, liftToNull, method);
}
public static BinaryExpression LessThan (Expression left, Expression right)
{
return LessThan (left, right, false, null);
}
public static BinaryExpression LessThan (Expression left, Expression right, bool liftToNull, MethodInfo method)
{
method = BinaryCoreCheck ("op_LessThan", left, right, method);
return MakeBoolBinary (ExpressionType.LessThan, left, right, liftToNull, method);
}
public static BinaryExpression LessThanOrEqual (Expression left, Expression right)
{
return LessThanOrEqual (left, right, false, null);
}
public static BinaryExpression LessThanOrEqual (Expression left, Expression right, bool liftToNull, MethodInfo method)
{
method = BinaryCoreCheck ("op_LessThanOrEqual", left, right, method);
return MakeBoolBinary (ExpressionType.LessThanOrEqual, left, right, liftToNull, method);
}
//
// Miscelaneous
//
static void CheckArray (Expression array)
{
if (array == null)
throw new ArgumentNullException ("array");
if (!array.Type.IsArray)
throw new ArgumentException ("The array argument must be of type array");
}
public static BinaryExpression ArrayIndex (Expression array, Expression index)
{
CheckArray (array);
if (index == null)
throw new ArgumentNullException ("index");
if (array.Type.GetArrayRank () != 1)
throw new ArgumentException ("The array argument must be a single dimensional array");
if (index.Type != typeof (int))
throw new ArgumentException ("The index must be of type int");
return new BinaryExpression (ExpressionType.ArrayIndex, array.Type.GetElementType (), array, index);
}
public static BinaryExpression Coalesce (Expression left, Expression right)
{
return Coalesce (left, right, null);
}
static BinaryExpression MakeCoalesce (Expression left, Expression right)
{
Type result = null;
if (left.Type.IsNullable ()) {
Type lbase = left.Type.GetNotNullableType ();
if (!right.Type.IsNullable () && right.Type.IsAssignableTo (lbase))
result = lbase;
}
if (result == null && right.Type.IsAssignableTo (left.Type))
result = left.Type;
if (result == null) {
if (left.Type.IsNullable () && left.Type.GetNotNullableType ().IsAssignableTo (right.Type))
result = right.Type;
}
if (result == null)
throw new ArgumentException ("Incompatible argument types");
return new BinaryExpression (ExpressionType.Coalesce, result, left, right, false, false, null, null);
}
static BinaryExpression MakeConvertedCoalesce (Expression left, Expression right, LambdaExpression conversion)
{
var invoke = conversion.Type.GetInvokeMethod ();
CheckNotVoid (invoke.ReturnType);
if (invoke.ReturnType != right.Type)
throw new InvalidOperationException ("Conversion return type doesn't march right type");
var parameters = invoke.GetParameters ();
if (parameters.Length != 1)
throw new ArgumentException ("Conversion has wrong number of parameters");
if (!IsAssignableToParameterType (left.Type, parameters [0]))
throw new InvalidOperationException ("Conversion argument doesn't marcht left type");
return new BinaryExpression (ExpressionType.Coalesce, right.Type, left, right, false, false, null, conversion);
}
public static BinaryExpression Coalesce (Expression left, Expression right, LambdaExpression conversion)
{
if (left == null)
throw new ArgumentNullException ("left");
if (right == null)
throw new ArgumentNullException ("right");
//
// First arg must ne nullable (either Nullable<T> or a reference type
//
if (left.Type.IsValueType && !left.Type.IsNullable ())
throw new InvalidOperationException ("Left expression can never be null");
if (conversion != null)
return MakeConvertedCoalesce (left, right, conversion);
return MakeCoalesce (left, right);
}
//
// MakeBinary constructors
//
public static BinaryExpression MakeBinary (ExpressionType binaryType, Expression left, Expression right)
{
return MakeBinary (binaryType, left, right, false, null);
}
public static BinaryExpression MakeBinary (ExpressionType binaryType, Expression left, Expression right, bool liftToNull, MethodInfo method)
{
return MakeBinary (binaryType, left, right, liftToNull, method, null);
}
public static BinaryExpression MakeBinary (ExpressionType binaryType, Expression left, Expression right, bool liftToNull, MethodInfo method, LambdaExpression conversion)
{
switch (binaryType) {
case ExpressionType.Add:
return Add (left, right, method);
case ExpressionType.AddChecked:
return AddChecked (left, right, method);
case ExpressionType.AndAlso:
return AndAlso (left, right);
case ExpressionType.Coalesce:
return Coalesce (left, right, conversion);
case ExpressionType.Divide:
return Divide (left, right, method);
case ExpressionType.Equal:
return Equal (left, right, liftToNull, method);
case ExpressionType.ExclusiveOr:
return ExclusiveOr (left, right, method);
case ExpressionType.GreaterThan:
return GreaterThan (left, right, liftToNull, method);
case ExpressionType.GreaterThanOrEqual:
return GreaterThanOrEqual (left, right, liftToNull, method);
case ExpressionType.LeftShift:
return LeftShift (left, right, method);
case ExpressionType.LessThan:
return LessThan (left, right, liftToNull, method);
case ExpressionType.LessThanOrEqual:
return LessThanOrEqual (left, right, liftToNull, method);
case ExpressionType.Modulo:
return Modulo (left, right, method);
case ExpressionType.Multiply:
return Multiply (left, right, method);
case ExpressionType.MultiplyChecked:
return MultiplyChecked (left, right, method);
case ExpressionType.NotEqual:
return NotEqual (left, right, liftToNull, method);
case ExpressionType.OrElse:
return OrElse (left, right);
case ExpressionType.Power:
return Power (left, right, method);
case ExpressionType.RightShift:
return RightShift (left, right, method);
case ExpressionType.Subtract:
return Subtract (left, right, method);
case ExpressionType.SubtractChecked:
return SubtractChecked (left, right, method);
case ExpressionType.And:
return And (left, right, method);
case ExpressionType.Or:
return Or (left, right, method);
}
throw new ArgumentException ("MakeBinary expect a binary node type");
}
#endregion
public static MethodCallExpression ArrayIndex (Expression array, params Expression [] indexes)
{
return ArrayIndex (array, indexes as IEnumerable<Expression>);
}
public static MethodCallExpression ArrayIndex (Expression array, IEnumerable<Expression> indexes)
{
CheckArray (array);
if (indexes == null)
throw new ArgumentNullException ("indexes");
var args = indexes.ToReadOnlyCollection ();
if (array.Type.GetArrayRank () != args.Count)
throw new ArgumentException ("The number of arguments doesn't match the rank of the array");
foreach (var arg in args)
if (arg.Type != typeof (int))
throw new ArgumentException ("The index must be of type int");
return Call (array, array.Type.GetMethod ("Get", PublicInstance), args);
}
public static UnaryExpression ArrayLength (Expression array)
{
if (array == null)
throw new ArgumentNullException ("array");
if (!array.Type.IsArray)
throw new ArgumentException ("The type of the expression must me Array");
if (array.Type.GetArrayRank () != 1)
throw new ArgumentException ("The array must be a single dimensional array");
return new UnaryExpression (ExpressionType.ArrayLength, array, typeof (int));
}
public static MemberAssignment Bind (MemberInfo member, Expression expression)
{
if (member == null)
throw new ArgumentNullException ("member");
if (expression == null)
throw new ArgumentNullException ("expression");
Type type = null;
var prop = member as PropertyInfo;
if (prop != null && prop.GetSetMethod (true) != null)
type = prop.PropertyType;
var field = member as FieldInfo;
if (field != null)
type = field.FieldType;
if (type == null)
throw new ArgumentException ("member");
if (!expression.Type.IsAssignableTo (type))
throw new ArgumentException ("member");
return new MemberAssignment (member, expression);
}
public static MemberAssignment Bind (MethodInfo propertyAccessor, Expression expression)
{
if (propertyAccessor == null)
throw new ArgumentNullException ("propertyAccessor");
if (expression == null)
throw new ArgumentNullException ("expression");
CheckNonGenericMethod (propertyAccessor);
var prop = GetAssociatedProperty (propertyAccessor);
if (prop == null)
throw new ArgumentException ("propertyAccessor");
var setter = prop.GetSetMethod (true);
if (setter == null)
throw new ArgumentException ("setter");
if (!expression.Type.IsAssignableTo (prop.PropertyType))
throw new ArgumentException ("member");
return new MemberAssignment (prop, expression);
}
public static MethodCallExpression Call (Expression instance, MethodInfo method)
{
return Call (instance, method, null as IEnumerable<Expression>);
}
public static MethodCallExpression Call (MethodInfo method, params Expression [] arguments)
{
return Call (null, method, arguments as IEnumerable<Expression>);
}
public static MethodCallExpression Call (Expression instance, MethodInfo method, params Expression [] arguments)
{
return Call (instance, method, arguments as IEnumerable<Expression>);
}
public static MethodCallExpression Call (Expression instance, MethodInfo method, IEnumerable<Expression> arguments)
{
if (method == null)
throw new ArgumentNullException ("method");
if (instance == null && !method.IsStatic)
throw new ArgumentNullException ("instance");
if (method.IsStatic && instance != null)
throw new ArgumentException ("instance");
if (!method.IsStatic && !instance.Type.IsAssignableTo (method.DeclaringType))
throw new ArgumentException ("Type is not assignable to the declaring type of the method");
var args = CheckMethodArguments (method, arguments);
return new MethodCallExpression (instance, method, args);
}
static Type [] CollectTypes (IEnumerable<Expression> expressions)
{
return (from arg in expressions select arg.Type).ToArray ();
}
static MethodInfo TryMakeGeneric (MethodInfo method, Type [] args)
{
if (method == null)
return null;
if (!method.IsGenericMethod && (args == null || args.Length == 0))
return method;
if (args.Length == method.GetGenericArguments ().Length)
return method.MakeGenericMethod (args);
return null;
}
public static MethodCallExpression Call (Expression instance, string methodName, Type [] typeArguments, params Expression [] arguments)
{
if (instance == null)
throw new ArgumentNullException ("instance");
if (methodName == null)
throw new ArgumentNullException ("methodName");
var method = TryGetMethod (instance.Type, methodName, AllInstance,
CollectTypes (arguments), typeArguments);
var args = CheckMethodArguments (method, arguments);
return new MethodCallExpression (instance, method, args);
}
static bool MethodMatch (MethodInfo method, string name, Type [] parameterTypes, Type [] argumentTypes)
{
if (method.Name != name)
return false;
var parameters = method.GetParameters ();
if (parameters.Length != parameterTypes.Length)
return false;
if (method.IsGenericMethod && method.IsGenericMethodDefinition) {
var closed = TryMakeGeneric (method, argumentTypes);
if (closed == null)
return false;
return MethodMatch (closed, name, parameterTypes, argumentTypes);
} else if (!method.IsGenericMethod && (argumentTypes != null && argumentTypes.Length > 0))
return false;
for (int i = 0; i < parameters.Length; i++) {
var type = parameterTypes [i];
var parameter = parameters [i];
if (!IsAssignableToParameterType (type, parameter)
&& !IsExpressionOfParameter (type, parameter.ParameterType))
return false;
}
return true;
}
static bool IsExpressionOfParameter (Type type, Type ptype)
{
return ptype.IsGenericInstanceOf (typeof (Expression<>)) && ptype.GetFirstGenericArgument () == type;
}
static MethodInfo TryGetMethod (Type type, string methodName, BindingFlags flags, Type [] parameterTypes, Type [] argumentTypes)
{
var methods = from meth in type.GetMethods (flags)
where MethodMatch (meth, methodName, parameterTypes, argumentTypes)
select meth;
if (methods.Count () > 1)
throw new InvalidOperationException ("Too many method candidates");
var method = TryMakeGeneric (methods.FirstOrDefault (), argumentTypes);
if (method != null)
return method;
throw new InvalidOperationException ("No such method");
}
public static MethodCallExpression Call (Type type, string methodName, Type [] typeArguments, params Expression [] arguments)
{
if (type == null)
throw new ArgumentNullException ("type");
if (methodName == null)
throw new ArgumentNullException ("methodName");
var method = TryGetMethod (type, methodName, AllStatic,
CollectTypes (arguments), typeArguments);
var args = CheckMethodArguments (method, arguments);
return new MethodCallExpression (method, args);
}
public static ConditionalExpression Condition (Expression test, Expression ifTrue, Expression ifFalse)
{
if (test == null)
throw new ArgumentNullException ("test");
if (ifTrue == null)
throw new ArgumentNullException ("ifTrue");
if (ifFalse == null)
throw new ArgumentNullException ("ifFalse");
if (test.Type != typeof (bool))
throw new ArgumentException ("Test expression should be of type bool");
if (ifTrue.Type != ifFalse.Type)
throw new ArgumentException ("The ifTrue and ifFalse type do not match");
return new ConditionalExpression (test, ifTrue, ifFalse);
}
public static ConstantExpression Constant (object value)
{
if (value == null)
return new ConstantExpression (null, typeof (object));
return Constant (value, value.GetType ());
}
public static ConstantExpression Constant (object value, Type type)
{
if (type == null)
throw new ArgumentNullException ("type");
//
// value must be compatible with type, no conversions
// are allowed
//
if (value == null){
if (type.IsValueType && !type.IsNullable ())
throw new ArgumentException ();
} else {
if (!(type.IsValueType && type.IsNullable ()) && !value.GetType ().IsAssignableTo (type))
throw new ArgumentException ();
}
return new ConstantExpression (value, type);
}
static bool IsConvertiblePrimitive (Type type)
{
var t = type.GetNotNullableType ();
if (t == typeof (bool))
return false;
if (t.IsEnum)
return true;
return t.IsPrimitive;
}
internal static bool IsPrimitiveConversion (Type type, Type target)
{
if (type == target)
return true;
if (type.IsNullable () && target == type.GetNotNullableType ())
return true;
if (target.IsNullable () && type == target.GetNotNullableType ())
return true;
if (IsConvertiblePrimitive (type) && IsConvertiblePrimitive (target))
return true;
return false;
}
internal static bool IsReferenceConversion (Type type, Type target)
{
if (type == target)
return true;
if (type == typeof (object) || target == typeof (object))
return true;
if (type.IsInterface || target.IsInterface)
return true;
if (type.IsValueType || target.IsValueType)
return false;
if (type.IsAssignableTo (target) || target.IsAssignableTo (type))
return true;
return false;
}
public static UnaryExpression Convert (Expression expression, Type type)
{
return Convert (expression, type, null);
}
static MethodInfo GetUserConversionMethod (Type type, Type target)
{
var method = GetUnaryOperator ("op_Explicit", type, type, target);
if (method == null)
method = GetUnaryOperator ("op_Implicit", type, type, target);
if (method == null)
method = GetUnaryOperator ("op_Explicit", target, type, target);
if (method == null)
method = GetUnaryOperator ("op_Implicit", target, type, target);
if (method == null)
throw new InvalidOperationException ();
return method;
}
public static UnaryExpression Convert (Expression expression, Type type, MethodInfo method)
{
if (expression == null)
throw new ArgumentNullException ("expression");
if (type == null)
throw new ArgumentNullException ("type");
var et = expression.Type;
if (method != null)
CheckUnaryMethod (method, et);
else if (!IsPrimitiveConversion (et, type) && !IsReferenceConversion (et, type))
method = GetUserConversionMethod (et, type);
return new UnaryExpression (ExpressionType.Convert,
expression, type, method,
IsConvertNodeLifted (method, expression, type));
}
static bool IsConvertNodeLifted (MethodInfo method, Expression operand, Type target)
{
if (method == null)
return operand.Type.IsNullable () || target.IsNullable ();
if (operand.Type.IsNullable () && !ParameterMatch (method, operand.Type))
return true;
if (target.IsNullable () && !ReturnTypeMatch (method, target))
return true;
return false;
}
static bool ParameterMatch (MethodInfo method, Type type)
{
return method.GetParameters () [0].ParameterType == type;
}
static bool ReturnTypeMatch (MethodInfo method, Type type)
{
return method.ReturnType == type;
}
public static UnaryExpression ConvertChecked (Expression expression, Type type)
{
return ConvertChecked (expression, type, null);
}
public static UnaryExpression ConvertChecked (Expression expression, Type type, MethodInfo method)
{
if (expression == null)
throw new ArgumentNullException ("expression");
if (type == null)
throw new ArgumentNullException ("type");
var et = expression.Type;
if (method != null)
CheckUnaryMethod (method, et);
else if (IsReferenceConversion (et, type))
return Convert (expression, type, method);
else if (!IsPrimitiveConversion (et, type))
method = GetUserConversionMethod (et, type);
return new UnaryExpression (ExpressionType.ConvertChecked,
expression, type, method,
IsConvertNodeLifted (method, expression, type));
}
public static ElementInit ElementInit (MethodInfo addMethod, params Expression [] arguments)
{
return ElementInit (addMethod, arguments as IEnumerable<Expression>);
}
public static ElementInit ElementInit (MethodInfo addMethod, IEnumerable<Expression> arguments)
{
if (addMethod == null)
throw new ArgumentNullException ("addMethod");
if (arguments == null)
throw new ArgumentNullException ("arguments");
if (addMethod.Name.ToLower (CultureInfo.InvariantCulture) != "add")
throw new ArgumentException ("addMethod");
if (addMethod.IsStatic)
throw new ArgumentException ("addMethod must be an instance method", "addMethod");
var args = CheckMethodArguments (addMethod, arguments);
return new ElementInit (addMethod, args);
}
public static MemberExpression Field (Expression expression, FieldInfo field)
{
if (field == null)
throw new ArgumentNullException ("field");
if (!field.IsStatic) {
if (expression == null)
throw new ArgumentNullException ("expression");
if (!expression.Type.IsAssignableTo (field.DeclaringType))
throw new ArgumentException ("field");
} else if (expression != null)
throw new ArgumentException ("expression");
return new MemberExpression (expression, field, field.FieldType);
}
public static MemberExpression Field (Expression expression, string fieldName)
{
if (expression == null)
throw new ArgumentNullException ("expression");
var field = expression.Type.GetField (fieldName, AllInstance);
if (field == null)
throw new ArgumentException (string.Format ("No field named {0} on {1}", fieldName, expression.Type));
return new MemberExpression (expression, field, field.FieldType);
}
public static Type GetActionType (params Type [] typeArgs)
{
if (typeArgs == null)
throw new ArgumentNullException ("typeArgs");
if (typeArgs.Length > 4)
throw new ArgumentException ("No Action type of this arity");
if (typeArgs.Length == 0)
return typeof (Action);
Type action = null;
switch (typeArgs.Length) {
case 1:
action = typeof (Action<>);
break;
case 2:
action = typeof (Action<,>);
break;
case 3:
action = typeof (Action<,,>);
break;
case 4:
action = typeof (Action<,,,>);
break;
}
return action.MakeGenericType (typeArgs);
}
public static Type GetFuncType (params Type [] typeArgs)
{
if (typeArgs == null)
throw new ArgumentNullException ("typeArgs");
if (typeArgs.Length < 1 || typeArgs.Length > 5)
throw new ArgumentException ("No Func type of this arity");
Type func = null;
switch (typeArgs.Length) {
case 1:
func = typeof (Func<>);
break;
case 2:
func = typeof (Func<,>);
break;
case 3:
func = typeof (Func<,,>);
break;
case 4:
func = typeof (Func<,,,>);
break;
case 5:
func = typeof (Func<,,,,>);
break;
}
return func.MakeGenericType (typeArgs);
}
public static InvocationExpression Invoke (Expression expression, params Expression [] arguments)
{
return Invoke (expression, arguments as IEnumerable<Expression>);
}
static Type GetInvokableType (Type t)
{
if (t.IsAssignableTo (typeof (Delegate)))
return t;
return GetGenericType (t, typeof (Expression<>));
}
static Type GetGenericType (Type t, Type def)
{
if (t == null)
return null;
if (t.IsGenericType && t.GetGenericTypeDefinition () == def)
return t;
return GetGenericType (t.BaseType, def);
}
public static InvocationExpression Invoke (Expression expression, IEnumerable<Expression> arguments)
{
if (expression == null)
throw new ArgumentNullException ("expression");
var type = GetInvokableType (expression.Type);
if (type == null)
throw new ArgumentException ("The type of the expression is not invokable");
var args = arguments.ToReadOnlyCollection ();
CheckForNull (args, "arguments");
var invoke = type.GetInvokeMethod ();
if (invoke == null)
throw new ArgumentException ("expression");
if (invoke.GetParameters ().Length != args.Count)
throw new InvalidOperationException ("Arguments count doesn't match parameters length");
args = CheckMethodArguments (invoke, args);
return new InvocationExpression (expression, invoke.ReturnType, args);
}
static bool CanAssign (Type target, Type source)
{
// This catches object and value type mixage, type compatibility is handled later
if (target.IsValueType ^ source.IsValueType)
return false;
return source.IsAssignableTo (target);
}
static Expression CheckLambda (Type delegateType, Expression body, ReadOnlyCollection<ParameterExpression> parameters)
{
if (!delegateType.IsSubclassOf (typeof (System.Delegate)))
throw new ArgumentException ("delegateType");
var invoke = delegateType.GetInvokeMethod ();
if (invoke == null)
throw new ArgumentException ("delegate must contain an Invoke method", "delegateType");
var invoke_parameters = invoke.GetParameters ();
if (invoke_parameters.Length != parameters.Count)
throw new ArgumentException (string.Format ("Different number of arguments in delegate {0}", delegateType), "delegateType");
for (int i = 0; i < invoke_parameters.Length; i++) {
var parameter = parameters [i];
if (parameter == null)
throw new ArgumentNullException ("parameters");
if (!CanAssign (parameter.Type, invoke_parameters [i].ParameterType))
throw new ArgumentException (String.Format ("Can not assign a {0} to a {1}", invoke_parameters [i].ParameterType, parameter.Type));
}
if (invoke.ReturnType != typeof (void)) {
if (!CanAssign (invoke.ReturnType, body.Type)) {
if (invoke.ReturnType.IsExpression ())
return Expression.Quote (body);
throw new ArgumentException (String.Format ("body type {0} can not be assigned to {1}", body.Type, invoke.ReturnType));
}
}
return body;
}
public static Expression<TDelegate> Lambda<TDelegate> (Expression body, params ParameterExpression [] parameters)
{
return Lambda<TDelegate> (body, parameters as IEnumerable<ParameterExpression>);
}
public static Expression<TDelegate> Lambda<TDelegate> (Expression body, IEnumerable<ParameterExpression> parameters)
{
if (body == null)
throw new ArgumentNullException ("body");
var ps = parameters.ToReadOnlyCollection ();
body = CheckLambda (typeof (TDelegate), body, ps);
return new Expression<TDelegate> (body, ps);
}
public static LambdaExpression Lambda (Expression body, params ParameterExpression [] parameters)
{
if (body == null)
throw new ArgumentNullException ("body");
if (parameters.Length > 4)
throw new ArgumentException ("Too many parameters");
return Lambda (GetDelegateType (body.Type, parameters), body, parameters);
}
static Type GetDelegateType (Type return_type, ParameterExpression [] parameters)
{
if (parameters == null)
parameters = new ParameterExpression [0];
if (return_type == typeof (void))
return GetActionType (parameters.Select (p => p.Type).ToArray ());
var types = new Type [parameters.Length + 1];
for (int i = 0; i < types.Length - 1; i++)
types [i] = parameters [i].Type;
types [types.Length - 1] = return_type;
return GetFuncType (types);
}
public static LambdaExpression Lambda (Type delegateType, Expression body, params ParameterExpression [] parameters)
{
return Lambda (delegateType, body, parameters as IEnumerable<ParameterExpression>);
}
static LambdaExpression CreateExpressionOf (Type type, Expression body, ReadOnlyCollection<ParameterExpression> parameters)
{
return (LambdaExpression) typeof (Expression<>).MakeGenericType (type).GetConstructor (
NonPublicInstance, null, new [] { typeof (Expression), typeof (ReadOnlyCollection<ParameterExpression>) }, null).Invoke (new object [] { body, parameters } );
}
public static LambdaExpression Lambda (Type delegateType, Expression body, IEnumerable<ParameterExpression> parameters)
{
if (delegateType == null)
throw new ArgumentNullException ("delegateType");
if (body == null)
throw new ArgumentNullException ("body");
var ps = parameters.ToReadOnlyCollection ();
body = CheckLambda (delegateType, body, ps);
return CreateExpressionOf (delegateType, body, ps);
}
public static MemberListBinding ListBind (MemberInfo member, params ElementInit [] initializers)
{
return ListBind (member, initializers as IEnumerable<ElementInit>);
}
static void CheckIsAssignableToIEnumerable (Type t)
{
if (!t.IsAssignableTo (typeof (IEnumerable)))
throw new ArgumentException (string.Format ("Type {0} doesn't implemen IEnumerable", t));
}
public static MemberListBinding ListBind (MemberInfo member, IEnumerable<ElementInit> initializers)
{
if (member == null)
throw new ArgumentNullException ("member");
if (initializers == null)
throw new ArgumentNullException ("initializers");
var inits = initializers.ToReadOnlyCollection ();
CheckForNull (inits, "initializers");
member.OnFieldOrProperty (
field => CheckIsAssignableToIEnumerable (field.FieldType),
prop => CheckIsAssignableToIEnumerable (prop.PropertyType));
return new MemberListBinding (member, inits);
}
public static MemberListBinding ListBind (MethodInfo propertyAccessor, params ElementInit [] initializers)
{
return ListBind (propertyAccessor, initializers as IEnumerable<ElementInit>);
}
static void CheckForNull<T> (ReadOnlyCollection<T> collection, string name) where T : class
{
foreach (var t in collection)
if (t == null)
throw new ArgumentNullException (name);
}
public static MemberListBinding ListBind (MethodInfo propertyAccessor, IEnumerable<ElementInit> initializers)
{
if (propertyAccessor == null)
throw new ArgumentNullException ("propertyAccessor");
if (initializers == null)
throw new ArgumentNullException ("initializers");
var inits = initializers.ToReadOnlyCollection ();
CheckForNull (inits, "initializers");
var prop = GetAssociatedProperty (propertyAccessor);
if (prop == null)
throw new ArgumentException ("propertyAccessor");
CheckIsAssignableToIEnumerable (prop.PropertyType);
return new MemberListBinding (prop, inits);
}
public static ListInitExpression ListInit (NewExpression newExpression, params ElementInit [] initializers)
{
return ListInit (newExpression, initializers as IEnumerable<ElementInit>);
}
public static ListInitExpression ListInit (NewExpression newExpression, IEnumerable<ElementInit> initializers)
{
var inits = CheckListInit (newExpression, initializers);
return new ListInitExpression (newExpression, inits);
}
public static ListInitExpression ListInit (NewExpression newExpression, params Expression [] initializers)
{
return ListInit (newExpression, initializers as IEnumerable<Expression>);
}
public static ListInitExpression ListInit (NewExpression newExpression, IEnumerable<Expression> initializers)
{
var inits = CheckListInit (newExpression, initializers);
var add_method = GetAddMethod (newExpression.Type, inits [0].Type);
if (add_method == null)
throw new InvalidOperationException ("No suitable add method found");
return new ListInitExpression (newExpression, CreateInitializers (add_method, inits));
}
static ReadOnlyCollection<ElementInit> CreateInitializers (MethodInfo add_method, ReadOnlyCollection<Expression> initializers)
{
return (from init in initializers select Expression.ElementInit (add_method, init)).ToReadOnlyCollection ();
}
static MethodInfo GetAddMethod (Type type, Type arg)
{
return type.GetMethod ("Add", PublicInstance | BindingFlags.IgnoreCase, null, new [] { arg }, null);
}
public static ListInitExpression ListInit (NewExpression newExpression, MethodInfo addMethod, params Expression [] initializers)
{
return ListInit (newExpression, addMethod, initializers as IEnumerable<Expression>);
}
static ReadOnlyCollection<T> CheckListInit<T> (NewExpression newExpression, IEnumerable<T> initializers) where T : class
{
if (newExpression == null)
throw new ArgumentNullException ("newExpression");
if (initializers == null)
throw new ArgumentNullException ("initializers");
if (!newExpression.Type.IsAssignableTo (typeof (IEnumerable)))
throw new InvalidOperationException ("The type of the new expression does not implement IEnumerable");
var inits = initializers.ToReadOnlyCollection ();
if (inits.Count == 0)
throw new ArgumentException ("Empty initializers");
CheckForNull (inits, "initializers");
return inits;
}
public static ListInitExpression ListInit (NewExpression newExpression, MethodInfo addMethod, IEnumerable<Expression> initializers)
{
var inits = CheckListInit (newExpression, initializers);
if (addMethod != null) {
if (addMethod.Name.ToLower (CultureInfo.InvariantCulture) != "add")
throw new ArgumentException ("addMethod");
var parameters = addMethod.GetParameters ();
if (parameters.Length != 1)
throw new ArgumentException ("addMethod");
foreach (var expression in inits)
if (!IsAssignableToParameterType (expression.Type, parameters [0]))
throw new InvalidOperationException ("Initializer not assignable to the add method parameter type");
}
if (addMethod == null)
addMethod = GetAddMethod (newExpression.Type, inits [0].Type);
if (addMethod == null)
throw new InvalidOperationException ("No suitable add method found");
return new ListInitExpression (newExpression, CreateInitializers (addMethod, inits));
}
public static MemberExpression MakeMemberAccess (Expression expression, MemberInfo member)
{
if (expression == null)
throw new ArgumentNullException ("expression");
if (member == null)
throw new ArgumentNullException ("member");
var field = member as FieldInfo;
if (field != null)
return Field (expression, field);
var property = member as PropertyInfo;
if (property != null)
return Property (expression, property);
throw new ArgumentException ("Member should either be a field or a property");
}
public static UnaryExpression MakeUnary (ExpressionType unaryType, Expression operand, Type type)
{
return MakeUnary (unaryType, operand, type, null);
}
public static UnaryExpression MakeUnary (ExpressionType unaryType, Expression operand, Type type, MethodInfo method)
{
switch (unaryType) {
case ExpressionType.ArrayLength:
return ArrayLength (operand);
case ExpressionType.Convert:
return Convert (operand, type, method);
case ExpressionType.ConvertChecked:
return ConvertChecked (operand, type, method);
case ExpressionType.Negate:
return Negate (operand, method);
case ExpressionType.NegateChecked:
return NegateChecked (operand, method);
case ExpressionType.Not:
return Not (operand, method);
case ExpressionType.Quote:
return Quote (operand);
case ExpressionType.TypeAs:
return TypeAs (operand, type);
case ExpressionType.UnaryPlus:
return UnaryPlus (operand, method);
}
throw new ArgumentException ("MakeUnary expect an unary operator");
}
public static MemberMemberBinding MemberBind (MemberInfo member, params MemberBinding [] bindings)
{
return MemberBind (member, bindings as IEnumerable<MemberBinding>);
}
public static MemberMemberBinding MemberBind (MemberInfo member, IEnumerable<MemberBinding> bindings)
{
if (member == null)
throw new ArgumentNullException ("member");
var type = member.OnFieldOrProperty (
field => field.FieldType,
prop => prop.PropertyType);
return new MemberMemberBinding (member, CheckMemberBindings (type, bindings));
}
public static MemberMemberBinding MemberBind (MethodInfo propertyAccessor, params MemberBinding [] bindings)
{
return MemberBind (propertyAccessor, bindings as IEnumerable<MemberBinding>);
}
public static MemberMemberBinding MemberBind (MethodInfo propertyAccessor, IEnumerable<MemberBinding> bindings)
{
if (propertyAccessor == null)
throw new ArgumentNullException ("propertyAccessor");
var bds = bindings.ToReadOnlyCollection ();
CheckForNull (bds, "bindings");
var prop = GetAssociatedProperty (propertyAccessor);
if (prop == null)
throw new ArgumentException ("propertyAccessor");
return new MemberMemberBinding (prop, CheckMemberBindings (prop.PropertyType, bindings));
}
static ReadOnlyCollection<MemberBinding> CheckMemberBindings (Type type, IEnumerable<MemberBinding> bindings)
{
if (bindings == null)
throw new ArgumentNullException ("bindings");
var bds = bindings.ToReadOnlyCollection ();
CheckForNull (bds, "bindings");
foreach (var binding in bds)
if (!type.IsAssignableTo (binding.Member.DeclaringType))
throw new ArgumentException ("Type not assignable to member type");
return bds;
}
public static MemberInitExpression MemberInit (NewExpression newExpression, params MemberBinding [] bindings)
{
return MemberInit (newExpression, bindings as IEnumerable<MemberBinding>);
}
public static MemberInitExpression MemberInit (NewExpression newExpression, IEnumerable<MemberBinding> bindings)
{
if (newExpression == null)
throw new ArgumentNullException ("newExpression");
return new MemberInitExpression (newExpression, CheckMemberBindings (newExpression.Type, bindings));
}
public static UnaryExpression Negate (Expression expression)
{
return Negate (expression, null);
}
public static UnaryExpression Negate (Expression expression, MethodInfo method)
{
method = UnaryCoreCheck ("op_UnaryNegation", expression, method, type => IsSignedNumber (type));
return MakeSimpleUnary (ExpressionType.Negate, expression, method);
}
public static UnaryExpression NegateChecked (Expression expression)
{
return NegateChecked (expression, null);
}
public static UnaryExpression NegateChecked (Expression expression, MethodInfo method)
{
method = UnaryCoreCheck ("op_UnaryNegation", expression, method, type => IsSignedNumber (type));
return MakeSimpleUnary (ExpressionType.NegateChecked, expression, method);
}
public static NewExpression New (ConstructorInfo constructor)
{
if (constructor == null)
throw new ArgumentNullException ("constructor");
if (constructor.GetParameters ().Length > 0)
throw new ArgumentException ("Constructor must be parameter less");
return new NewExpression (constructor, (null as IEnumerable<Expression>).ToReadOnlyCollection (), null);
}
public static NewExpression New (Type type)
{
if (type == null)
throw new ArgumentNullException ("type");
CheckNotVoid (type);
var args = (null as IEnumerable<Expression>).ToReadOnlyCollection ();
if (type.IsValueType)
return new NewExpression (type, args);
var ctor = type.GetConstructor (Type.EmptyTypes);
if (ctor == null)
throw new ArgumentException ("Type doesn't have a parameter less constructor");
return new NewExpression (ctor, args, null);
}
public static NewExpression New (ConstructorInfo constructor, params Expression [] arguments)
{
return New (constructor, arguments as IEnumerable<Expression>);
}
public static NewExpression New (ConstructorInfo constructor, IEnumerable<Expression> arguments)
{
if (constructor == null)
throw new ArgumentNullException ("constructor");
var args = CheckMethodArguments (constructor, arguments);
return new NewExpression (constructor, args, null);
}
static IList<Expression> CreateArgumentList (IEnumerable<Expression> arguments)
{
if (arguments == null)
return arguments.ToReadOnlyCollection ();
return arguments.ToList ();
}
static void CheckNonGenericMethod (MethodBase method)
{
if (method.IsGenericMethodDefinition || method.ContainsGenericParameters)
throw new ArgumentException ("Can not used open generic methods");
}
static ReadOnlyCollection<Expression> CheckMethodArguments (MethodBase method, IEnumerable<Expression> args)
{
CheckNonGenericMethod (method);
var arguments = CreateArgumentList (args);
var parameters = method.GetParameters ();
if (arguments.Count != parameters.Length)
throw new ArgumentException ("The number of arguments doesn't match the number of parameters");
for (int i = 0; i < parameters.Length; i++) {
if (arguments [i] == null)
throw new ArgumentNullException ("arguments");
if (!IsAssignableToParameterType (arguments [i].Type, parameters [i])) {
if (!parameters [i].ParameterType.IsExpression ())
throw new ArgumentException ("arguments");
arguments [i] = Expression.Quote (arguments [i]);
}
}
return arguments.ToReadOnlyCollection ();
}
public static NewExpression New (ConstructorInfo constructor, IEnumerable<Expression> arguments, params MemberInfo [] members)
{
return New (constructor, arguments, members as IEnumerable<MemberInfo>);
}
public static NewExpression New (ConstructorInfo constructor, IEnumerable<Expression> arguments, IEnumerable<MemberInfo> members)
{
if (constructor == null)
throw new ArgumentNullException ("constructor");
var args = arguments.ToReadOnlyCollection ();
var mmbs = members.ToReadOnlyCollection ();
CheckForNull (args, "arguments");
CheckForNull (mmbs, "members");
args = CheckMethodArguments (constructor, arguments);
if (args.Count != mmbs.Count)
throw new ArgumentException ("Arguments count does not match members count");
for (int i = 0; i < mmbs.Count; i++) {
var member = mmbs [i];
Type type = null;
switch (member.MemberType) {
case MemberTypes.Field:
type = (member as FieldInfo).FieldType;
break;
case MemberTypes.Method:
type = (member as MethodInfo).ReturnType;
break;
case MemberTypes.Property:
var prop = member as PropertyInfo;
if (prop.GetGetMethod (true) == null)
throw new ArgumentException ("Property must have a getter");
type = (member as PropertyInfo).PropertyType;
break;
default:
throw new ArgumentException ("Member type not allowed");
}
if (!args [i].Type.IsAssignableTo (type))
throw new ArgumentException ("Argument type not assignable to member type");
}
return new NewExpression (constructor, args, mmbs);
}
public static NewArrayExpression NewArrayBounds (Type type, params Expression [] bounds)
{
return NewArrayBounds (type, bounds as IEnumerable<Expression>);
}
public static NewArrayExpression NewArrayBounds (Type type, IEnumerable<Expression> bounds)
{
if (type == null)
throw new ArgumentNullException ("type");
if (bounds == null)
throw new ArgumentNullException ("bounds");
CheckNotVoid (type);
var array_bounds = bounds.ToReadOnlyCollection ();
foreach (var expression in array_bounds)
if (!IsInt (expression.Type))
throw new ArgumentException ("The bounds collection can only contain expression of integers types");
return new NewArrayExpression (ExpressionType.NewArrayBounds, type.MakeArrayType (array_bounds.Count), array_bounds);
}
public static NewArrayExpression NewArrayInit (Type type, params Expression [] initializers)
{
return NewArrayInit (type, initializers as IEnumerable<Expression>);
}
public static NewArrayExpression NewArrayInit (Type type, IEnumerable<Expression> initializers)
{
if (type == null)
throw new ArgumentNullException ("type");
if (initializers == null)
throw new ArgumentNullException ("initializers");
CheckNotVoid (type);
var inits = initializers.ToReadOnlyCollection ();
foreach (var expression in inits) {
if (expression == null)
throw new ArgumentNullException ("initializers");
if (!expression.Type.IsAssignableTo (type))
throw new InvalidOperationException (
string.Format ("{0} IsAssignableTo {1}, expression [ {2} ] : {3}", expression.Type, type, expression.NodeType, expression));
// TODO: Quote elements if type == typeof (Expression)
}
return new NewArrayExpression (ExpressionType.NewArrayInit, type.MakeArrayType (), inits);
}
public static UnaryExpression Not (Expression expression)
{
return Not (expression, null);
}
public static UnaryExpression Not (Expression expression, MethodInfo method)
{
Func<Type, bool> validator = type => IsIntOrBool (type);
method = UnaryCoreCheck ("op_LogicalNot", expression, method, validator);
if (method == null)
method = UnaryCoreCheck ("op_OnesComplement", expression, method, validator);
return MakeSimpleUnary (ExpressionType.Not, expression, method);
}
static void CheckNotVoid (Type type)
{
if (type == typeof (void))
throw new ArgumentException ("Type can't be void");
}
public static ParameterExpression Parameter (Type type, string name)
{
if (type == null)
throw new ArgumentNullException ("type");
CheckNotVoid (type);
return new ParameterExpression (type, name);
}
public static MemberExpression Property (Expression expression, MethodInfo propertyAccessor)
{
if (propertyAccessor == null)
throw new ArgumentNullException ("propertyAccessor");
CheckNonGenericMethod (propertyAccessor);
if (!propertyAccessor.IsStatic) {
if (expression == null)
throw new ArgumentNullException ("expression");
if (!expression.Type.IsAssignableTo (propertyAccessor.DeclaringType))
throw new ArgumentException ("expression");
}
//
// .NET does not mandate that if the property is static, that the expression must be null
// fixes a bug exposed by Orchard's ContentItemRecordAlteration.Alteration
// else if (expression != null)
// throw new ArgumentException ("expression");
var prop = GetAssociatedProperty (propertyAccessor);
if (prop == null)
throw new ArgumentException (string.Format ("Method {0} has no associated property", propertyAccessor));
return new MemberExpression (expression, prop, prop.PropertyType);
}
static PropertyInfo GetAssociatedProperty (MethodInfo method)
{
if (method == null)
return null;
foreach (var prop in method.DeclaringType.GetProperties (All)) {
if (method.Equals (prop.GetGetMethod (true)))
return prop;
if (method.Equals (prop.GetSetMethod (true)))
return prop;
}
return null;
}
public static MemberExpression Property (Expression expression, PropertyInfo property)
{
if (property == null)
throw new ArgumentNullException ("property");
var getter = property.GetGetMethod (true);
if (getter == null)
throw new ArgumentException ("getter");
if (!getter.IsStatic) {
if (expression == null)
throw new ArgumentNullException ("expression");
if (!expression.Type.IsAssignableTo (property.DeclaringType))
throw new ArgumentException ("expression");
} else if (expression != null)
throw new ArgumentException ("expression");
return new MemberExpression (expression, property, property.PropertyType);
}
public static MemberExpression Property (Expression expression, string propertyName)
{
if (expression == null)
throw new ArgumentNullException ("expression");
var prop = expression.Type.GetProperty (propertyName, AllInstance);
if (prop == null)
throw new ArgumentException (string.Format ("No property named {0} on {1}", propertyName, expression.Type));
return new MemberExpression (expression, prop, prop.PropertyType);
}
public static MemberExpression PropertyOrField (Expression expression, string propertyOrFieldName)
{
if (expression == null)
throw new ArgumentNullException ("expression");
if (propertyOrFieldName == null)
throw new ArgumentNullException ("propertyOrFieldName");
var prop = expression.Type.GetProperty (propertyOrFieldName, AllInstance);
if (prop != null)
return new MemberExpression (expression, prop, prop.PropertyType);
var field = expression.Type.GetField (propertyOrFieldName, AllInstance);
if (field != null)
return new MemberExpression (expression, field, field.FieldType);
throw new ArgumentException (string.Format ("No field or property named {0} on {1}", propertyOrFieldName, expression.Type));
}
public static UnaryExpression Quote (Expression expression)
{
if (expression == null)
throw new ArgumentNullException ("expression");
return new UnaryExpression (ExpressionType.Quote, expression, expression.GetType ());
}
public static UnaryExpression TypeAs (Expression expression, Type type)
{
if (expression == null)
throw new ArgumentNullException ("expression");
if (type == null)
throw new ArgumentNullException ("type");
if (type.IsValueType && !type.IsNullable ())
throw new ArgumentException ("TypeAs expect a reference or a nullable type");
return new UnaryExpression (ExpressionType.TypeAs, expression, type);
}
public static TypeBinaryExpression TypeIs (Expression expression, Type type)
{
if (expression == null)
throw new ArgumentNullException ("expression");
if (type == null)
throw new ArgumentNullException ("type");
CheckNotVoid (type);
return new TypeBinaryExpression (ExpressionType.TypeIs, expression, type, typeof (bool));
}
public static UnaryExpression UnaryPlus (Expression expression)
{
return UnaryPlus (expression, null);
}
public static UnaryExpression UnaryPlus (Expression expression, MethodInfo method)
{
method = UnaryCoreCheck ("op_UnaryPlus", expression, method, type => IsNumber (type));
return MakeSimpleUnary (ExpressionType.UnaryPlus, expression, method);
}
static bool IsInt (Type t)
{
return t == typeof (byte) || t == typeof (sbyte) ||
t == typeof (short) || t == typeof (ushort) ||
t == typeof (int) || t == typeof (uint) ||
t == typeof (long) || t == typeof (ulong);
}
static bool IsIntOrBool (Type t)
{
return IsInt (t) || t == typeof (bool);
}
static bool IsNumber (Type t)
{
if (IsInt (t))
return true;
return t == typeof (float) || t == typeof (double);
}
static bool IsSignedNumber (Type t)
{
return IsNumber (t) && !IsUnsigned (t);
}
internal static bool IsUnsigned (Type t)
{
#if !TARGET_JVM
if (t.IsPointer)
return IsUnsigned (t.GetElementType ());
#endif
return t == typeof (ushort) ||
t == typeof (uint) ||
t == typeof (ulong) ||
t == typeof (byte);
}
//
// This method must be overwritten by derived classes to
// compile the expression
//
internal virtual void Emit (EmitContext ec)
{
throw new NotImplementedException (String.Format ("Emit method is not implemented in expression type {0}", GetType ()));
}
}
}
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