Class ExpressionTransformer

Namespace

Utils.Expressions

Assembly

Utils.dll

Provides an abstract base class to transform or rewrite LINQ expression trees. Subclasses may override the transformation logic for specific expression signatures.

public abstract class ExpressionTransformer

Inheritance

object

ExpressionTransformer

Derived

ExpressionDerivation<T>

ExpressionIntegration<T>

ExpressionSimplifier

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Extension Methods

DataUtils.ToDbValue(object?)

MathEx.Clamp<T>(T, T, T, IComparer<T>)

FluentExtensions.Failure<T>(T)

FluentExtensions.IsEqualTo<T, CT>(T, CT)

FluentExtensions.IsGreaterOrEqualsThan<T, CT>(T, CT)

FluentExtensions.IsGreaterThan<T, CT>(T, CT)

FluentExtensions.IsIn<T>(T, params T[])

FluentExtensions.IsLowerOrEqualsThan<T, CT>(T, CT)

FluentExtensions.IsLowerThan<T, CT>(T, CT)

FluentExtensions.IsNotIn<T>(T, params T[])

FluentExtensions.IsNotNull<T>(T)

FluentExtensions.IsNull<T>(T)

FluentExtensions.Success<T>(T)

FluentExtensions.Test<T>(T, Func<T, bool>)

ObjectUtils.Between<T>(T, IComparer<T>, T, T)

ObjectUtils.Between<T>(T, IComparer<T>, T, T, bool, bool)

ObjectUtils.DoAsync<T, Result>(T, Func<T, Task<Result>>, Func<Task<Result>>)

ObjectUtils.DoAsync<T, Result>(T, Func<T, Task<Result>>, Result)

ObjectUtils.DoAsync<T, Result>(T, Func<T, Result>, Func<Result>)

ObjectUtils.DoAsync<T, Result>(T, Func<T, Result>, Result)

ObjectUtils.Do<T, Result>(T, Func<T, Result>, Func<Result>)

ObjectUtils.Do<T, Result>(T, Func<T, Result>, Result)

ObjectUtils.In<T>(T, params T[])

ObjectUtils.NotIn<T>(T, params T[])

Validations.ArgMustBe<T>(T, Func<T, bool>, string, string)

Validations.ArgMustNotBe<T>(T, Func<T, bool>, string, string)

Validations.Arg<T>(T, string)

Validations.ValueMustNotBeNull<T>(T, string)

Validations.Variable<T>(T, string)

Constructors

ExpressionTransformer()

Initializes a new instance of the ExpressionTransformer class. During construction, it gathers all methods marked with ExpressionSignatureAttribute from the derived type.

protected ExpressionTransformer()

Methods

CopyExpression(Expression, params Expression[])

Creates a new expression of the same ExpressionType as e, using the supplied parameters as sub-expressions or arguments. If certain ExpressionType values are not supported by this switch, they are simply returned as-is or an exception is thrown.

protected static Expression CopyExpression(Expression e, params Expression[] parameters)

Parameters

e Expression

The original expression to copy.

parameters Expression[]

The sub-expressions to insert into the copied expression.

Returns

Expression

A new expression replicating the structure of e with possibly different sub-expressions.

FinalizeExpression(Expression, Expression[])

Called if no custom transformation method (annotated with ExpressionSignatureAttribute) is found. Allows final post-processing. The default implementation throws an exception.

protected virtual Expression FinalizeExpression(Expression e, Expression[] parameters)

Parameters

e Expression

The expression being finalized.

parameters Expression[]

The sub-expressions or operands for e.

Returns

Expression

A finalized expression.

Exceptions

Exception

Thrown by default to indicate that transformation cannot be completed.

PrepareExpression(Expression)

Prepares an expression for transformation. Subclasses can override this to apply initial logic before the main Transform(Expression) switch (e.g., caching). The default implementation returns the expression unchanged.

protected virtual Expression PrepareExpression(Expression e)

Parameters

e Expression

The expression to prepare.

Returns

Expression

The prepared expression.

ReplaceArguments(Expression, ParameterExpression[], Expression[])

Replaces all occurrences of oldParameters within e with the corresponding items in newParameters.

protected Expression ReplaceArguments(Expression e, ParameterExpression[] oldParameters, Expression[] newParameters)

Parameters

e Expression

The expression in which parameter references are replaced.

oldParameters ParameterExpression[]

The parameters to remove.

newParameters Expression[]

The new expressions that replace oldParameters.

Returns

Expression

A copy of e where specified parameters are replaced.

Transform(Expression)

Applies transformation rules to a given expression, returning a (potentially) modified expression. This method checks for known signatures (via ExpressionSignatureAttribute-annotated methods) and if a match is found, invokes the corresponding transformation function. If no signature method matches, it calls FinalizeExpression(Expression, Expression[]) by default.

protected Expression Transform(Expression e)

Parameters

e Expression

The expression to transform.

Returns

Expression

A possibly rewritten expression.