Class LvalExpressionVisitor

Expression visitor with tracking of "left values" (lvals) to guarantee rewrite safety.

Inheritance

System.Object

SafeExpressionVisitor

LvalExpressionVisitor

ExpressionOptimizer

Inherited Members

SafeExpressionVisitor.VisitBinary(BinaryExpression)

SafeExpressionVisitor.VisitBinaryUnsafe(BinaryExpression)

SafeExpressionVisitor.VisitBinaryConversion(LambdaExpression)

SafeExpressionVisitor.VisitListInit(ListInitExpression)

SafeExpressionVisitor.VisitListInitUnsafe(ListInitExpression)

SafeExpressionVisitor.VisitListInitNew(NewExpression)

SafeExpressionVisitor.VisitMemberInit(MemberInitExpression)

SafeExpressionVisitor.VisitMemberInitUnsafe(MemberInitExpression)

SafeExpressionVisitor.VisitMemberInitNew(NewExpression)

SafeExpressionVisitor.VisitRuntimeVariables(RuntimeVariablesExpression)

SafeExpressionVisitor.VisitRuntimeVariablesUnsafe(RuntimeVariablesExpression)

SafeExpressionVisitor.VisitUnary(UnaryExpression)

SafeExpressionVisitor.VisitUnaryUnsafe(UnaryExpression)

SafeExpressionVisitor.VisitUnaryQuote(UnaryExpression)

SafeExpressionVisitor.VisitUnaryQuoteOperand(LambdaExpression)

Namespace: System.Linq.Expressions

Assembly: Nuqleon.Linq.Expressions.Optimizers.dll

Syntax

public class LvalExpressionVisitor : SafeExpressionVisitor

Remarks

Nodes of type System.Linq.Expressions.IndexExpression, System.Linq.Expressions.MemberExpression, and System.Linq.Expressions.ParameterExpression can be used as assignment targets and will be visited using specialized VisitIndex(IndexExpression, Boolean), VisitMember(MemberExpression, Boolean), and VisitParameter(ParameterExpression, Boolean) methods.

Constructors

LvalExpressionVisitor()

Declaration

public LvalExpressionVisitor()

Methods

GetInvokeMethod(Expression)

Gets the delegate invocation method of the specified expression that represents an invocation target.

Declaration

protected static MethodInfo GetInvokeMethod(Expression expression)

Parameters

Type	Name	Description
System.Linq.Expressions.Expression	expression	The invocation target expression.

Returns

Type	Description
System.Reflection.MethodInfo	The method representing the delegate invocation method of the invocation target expression.

IsAssignment(ExpressionType)

Checks if the specified node type represents an assignment expression node.

Declaration

protected static bool IsAssignment(ExpressionType nodeType)

Parameters

Type	Name	Description
System.Linq.Expressions.ExpressionType	nodeType	The node type to check.

Returns

Type	Description
System.Boolean	true if the specified node type represents an assignment expression node; otherwise, false.

VisitArgument(Expression, ParameterInfo)

Visits the expression argument using the corresponding parameter to determine whether the argument is assigned to a ref or out parameter. An argument that is passed by reference gets visited using VisitLval(Expression).

Declaration

protected virtual Expression VisitArgument(Expression argument, ParameterInfo parameter)

Parameters

Type	Name	Description
System.Linq.Expressions.Expression	argument	The argument expression to visit.
System.Reflection.ParameterInfo	parameter	The parameter corresponding to the argument.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the expression arguments.

VisitArguments(ReadOnlyCollection<Expression>, ParameterInfo[])

Visits the expression arguments using the corresponding parameters to determine whether each argument is assigned to a ref or out parameter. Arguments that are passed by reference get visited using VisitLval(Expression).

Declaration

protected ReadOnlyCollection<Expression> VisitArguments(ReadOnlyCollection<Expression> arguments, ParameterInfo[] parameters)

Parameters

Type	Name	Description
System.Collections.ObjectModel.ReadOnlyCollection<System.Linq.Expressions.Expression>	arguments	The argument expressions to visit.
System.Reflection.ParameterInfo[]	parameters	The parameters corresponding to the arguments.

Returns

Type	Description
System.Collections.ObjectModel.ReadOnlyCollection<System.Linq.Expressions.Expression>	The result of visiting the expression arguments.

VisitArguments(ReadOnlyCollection<Expression>, ParameterInfo[], Int32)

Visits the expression arguments using the corresponding parameters to determine whether each argument is assigned to a ref or out parameter. Arguments that are passed by reference get visited using VisitLval(Expression).

Declaration

protected virtual ReadOnlyCollection<Expression> VisitArguments(ReadOnlyCollection<Expression> arguments, ParameterInfo[] parameters, int skip)

Parameters

Type	Name	Description
System.Collections.ObjectModel.ReadOnlyCollection<System.Linq.Expressions.Expression>	arguments	The argument expressions to visit.
System.Reflection.ParameterInfo[]	parameters	The parameters corresponding to the arguments.
System.Int32	skip	The number of parameters to skip when pairing them with corresponding arguments.

Returns

Type	Description
System.Collections.ObjectModel.ReadOnlyCollection<System.Linq.Expressions.Expression>	The result of visiting the expression arguments.

VisitBinaryWithConversion(BinaryExpression)

Visits a binary expression that has a System.Linq.Expressions.BinaryExpression.Conversion, determines whether it is an assignment expression, and calls VisitBinaryWithConversion(BinaryExpression, Boolean).

Declaration

protected override sealed Expression VisitBinaryWithConversion(BinaryExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.BinaryExpression	node	The binary expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the binary expression.

Overrides

SafeExpressionVisitor.VisitBinaryWithConversion(BinaryExpression)

VisitBinaryWithConversion(BinaryExpression, Boolean)

Visits a binary expression that has a System.Linq.Expressions.BinaryExpression.Conversion using the specified assignment behavior. If the node represents an assignment, the System.Linq.Expressions.BinaryExpression.Left node is visited using VisitLval(Expression).

Declaration

protected virtual Expression VisitBinaryWithConversion(BinaryExpression node, bool isAssignment)

Parameters

Type	Name	Description
System.Linq.Expressions.BinaryExpression	node	The binary expression to visit.
System.Boolean	isAssignment	Indicates if the node represents an assignment.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the binary expression.

VisitBinaryWithoutConversion(BinaryExpression)

Visits a binary expression that has no System.Linq.Expressions.BinaryExpression.Conversion, determines whether it is an assignment expression, and calls VisitBinaryWithoutConversion(BinaryExpression, Boolean).

Declaration

protected override sealed Expression VisitBinaryWithoutConversion(BinaryExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.BinaryExpression	node	The binary expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the binary expression.

Overrides

SafeExpressionVisitor.VisitBinaryWithoutConversion(BinaryExpression)

VisitBinaryWithoutConversion(BinaryExpression, Boolean)

Visits a binary expression that has no System.Linq.Expressions.BinaryExpression.Conversion using the specified assignment behavior. If the node represents an assignment, the System.Linq.Expressions.BinaryExpression.Left node is visited using VisitLval(Expression).

Declaration

protected virtual Expression VisitBinaryWithoutConversion(BinaryExpression node, bool isAssignment)

Parameters

Type	Name	Description
System.Linq.Expressions.BinaryExpression	node	The binary expression to visit.
System.Boolean	isAssignment	Indicates if the node represents an assignment.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the binary expression.

VisitDynamic(DynamicExpression)

Visits a dynamic expression and visits System.Linq.Expressions.DynamicExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression).

Declaration

protected override sealed Expression VisitDynamic(DynamicExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.DynamicExpression	node	The dynamic expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the dynamic expression.

Remarks

This method is sealed in order to guarantee proper assignment target tracking. In order to guarantee assignment target tracking, override VisitDynamicCore(DynamicExpression) instead.

VisitDynamicCore(DynamicExpression)

Visits a dynamic expression and visits System.Linq.Expressions.DynamicExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression).

Declaration

protected virtual Expression VisitDynamicCore(DynamicExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.DynamicExpression	node	The dynamic expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the dynamic expression.

VisitIndex(IndexExpression)

Visits an index expression and visits the System.Linq.Expressions.IndexExpression.Object of a value type using VisitLval(Expression) and System.Linq.Expressions.IndexExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression). It is assumed that the index expression is not the target of an assignment itself.

Declaration

protected override sealed Expression VisitIndex(IndexExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.IndexExpression	node	The index expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the index expression.

VisitIndex(IndexExpression, Boolean)

Visits an index expression with the specified isLval behavior. See VisitIndex(IndexExpression) for more information about visitor behavior.

Declaration

protected virtual Expression VisitIndex(IndexExpression node, bool isLval)

Parameters

Type	Name	Description
System.Linq.Expressions.IndexExpression	node	The index expression to visit.
System.Boolean	isLval	Indicates whether the index expression occurs in an assignment target position.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the index expression.

VisitInvocation(InvocationExpression)

Visits an invocation expression and visits System.Linq.Expressions.InvocationExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression).

Declaration

protected override sealed Expression VisitInvocation(InvocationExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.InvocationExpression	node	The invocation expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the invocation expression.

Remarks

This method is sealed in order to guarantee proper assignment target tracking. In order to guarantee assignment target tracking, override VisitInvocationCore(InvocationExpression) instead.

VisitInvocationCore(InvocationExpression)

Visits an invocation expression and visits System.Linq.Expressions.InvocationExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression).

Declaration

protected virtual Expression VisitInvocationCore(InvocationExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.InvocationExpression	node	The invocation expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the invocation expression.

VisitLval(Expression)

Visits an expression that occurs in an assignment target position.

Declaration

protected virtual Expression VisitLval(Expression node)

Parameters

Type	Name	Description
System.Linq.Expressions.Expression	node	The expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the expression.

VisitMember(MemberExpression)

Visits a member expression and visits the System.Linq.Expressions.MemberExpression.Expression of a value type using VisitLval(Expression). It is assumed that the member expression is not the target of an assignment itself.

Declaration

protected override sealed Expression VisitMember(MemberExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.MemberExpression	node	The member expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the member expression.

VisitMember(MemberExpression, Boolean)

Visits a member expression with the specified isLval behavior. See VisitMember(MemberExpression) for more information about visitor behavior.

Declaration

protected virtual Expression VisitMember(MemberExpression node, bool isLval)

Parameters

Type	Name	Description
System.Linq.Expressions.MemberExpression	node	The member expression to visit.
System.Boolean	isLval	Indicates whether the member expression occurs in an assignment target position.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the member expression.

VisitMethodCall(MethodCallExpression)

Visits a method call expression and visits the System.Linq.Expressions.MethodCallExpression.Object of a value type using VisitLval(Expression) and System.Linq.Expressions.MethodCallExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression).

Declaration

protected override sealed Expression VisitMethodCall(MethodCallExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.MethodCallExpression	node	The method call expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the method call expression.

Remarks

This method is sealed in order to guarantee proper assignment target tracking. In order to guarantee assignment target tracking, override VisitMethodCallCore(MethodCallExpression) instead.

VisitMethodCallCore(MethodCallExpression)

Visits a method call expression and visits the System.Linq.Expressions.MethodCallExpression.Object of a value type using VisitLval(Expression) and System.Linq.Expressions.MethodCallExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression).

Declaration

protected virtual Expression VisitMethodCallCore(MethodCallExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.MethodCallExpression	node	The method call expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the method call expression.

VisitNew(NewExpression)

Visits a new expression and visits System.Linq.Expressions.NewExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression).

Declaration

protected override sealed Expression VisitNew(NewExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.NewExpression	node	The new expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the new expression.

VisitNewCore(NewExpression)

Visits a new expression and visits System.Linq.Expressions.NewExpression.Arguments that are passed to ref or out parameters using VisitLval(Expression).

Declaration

protected virtual Expression VisitNewCore(NewExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.NewExpression	node	The new expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the new expression.

VisitParameter(ParameterExpression)

Visits a parameter expression that does not occur as the target of an assignment.

Declaration

protected override sealed Expression VisitParameter(ParameterExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.ParameterExpression	node	The parameter expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the parameter expression.

VisitParameter(ParameterExpression, Boolean)

Visits a parameter expression with the specified isLval behavior.

Declaration

protected virtual Expression VisitParameter(ParameterExpression node, bool isLval)

Parameters

Type	Name	Description
System.Linq.Expressions.ParameterExpression	node	The parameter expression to visit.
System.Boolean	isLval	Indicates whether the parameter expression occurs in an assignment target position.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the parameter expression.

VisitRuntimeVariable(ParameterExpression)

Visits a runtime variable expression assuming it may get assigned to.

Declaration

protected override ParameterExpression VisitRuntimeVariable(ParameterExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.ParameterExpression	node	The runtime variable expression to visit.

Returns

Type	Description
System.Linq.Expressions.ParameterExpression	The result of visiting the runtime variable expression.

Overrides

SafeExpressionVisitor.VisitRuntimeVariable(ParameterExpression)

VisitUnaryNonQuote(UnaryExpression)

Visits a unary expression that's not a System.Linq.Expressions.ExpressionType.Quote, determines whether it is an assignment expression, and calls VisitUnaryNonQuote(UnaryExpression, Boolean).

Declaration

protected override sealed Expression VisitUnaryNonQuote(UnaryExpression node)

Parameters

Type	Name	Description
System.Linq.Expressions.UnaryExpression	node	The unary expression to visit.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the unary expression.

Overrides

SafeExpressionVisitor.VisitUnaryNonQuote(UnaryExpression)

VisitUnaryNonQuote(UnaryExpression, Boolean)

Visits a unary expression that's not a System.Linq.Expressions.ExpressionType.Quote using the specified assignment behavior. If the node represents an assignment, the System.Linq.Expressions.UnaryExpression.Operand is visited using VisitLval(Expression).

Declaration

protected virtual Expression VisitUnaryNonQuote(UnaryExpression node, bool isAssignment)

Parameters

Type	Name	Description
System.Linq.Expressions.UnaryExpression	node	The unary expression to visit.
System.Boolean	isAssignment	Indicates if the node represents an assignment.

Returns

Type	Description
System.Linq.Expressions.Expression	The result of visiting the unary expression.