Class Predicate

Provides extension methods for type Predicate<T> and predefined predicates.

Inheritance

object

Predicate

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: DotNext

Assembly: DotNext.dll

Syntax

public static class Predicate

Methods

And<T>(Predicate<T>, Predicate<T>)

Returns a predicate which computes logical AND between results of two other predicates.

Declaration

public static Predicate<T> And<T>(this Predicate<T> left, Predicate<T> right)

Parameters

Type	Name	Description
Predicate<T>	left	The first predicate acting as logical AND operand.
Predicate<T>	right	The second predicate acting as logical AND operand.

Returns

Type	Description
Predicate<T>	The predicate which computes logical AND between results of two other predicates.

Type Parameters

Name	Description
T	Type of the predicate argument.

AsConverter<T>(Predicate<T>)

Represents predicate as type Converter<TInput, TOutput>.

Declaration

public static Converter<T, bool> AsConverter<T>(this Predicate<T> predicate)

Parameters

Type	Name	Description
Predicate<T>	predicate	A predicate to convert.

Returns

Type	Description
Converter<T, bool>	A delegate of type Converter<TInput, TOutput> referencing the same method as original predicate.

Type Parameters

Name	Description
T	Type of predicate argument.

AsFunc<T>(Predicate<T>)

Represents predicate as type Func<T, TResult>.

Declaration

public static Func<T, bool> AsFunc<T>(this Predicate<T> predicate)

Parameters

Type	Name	Description
Predicate<T>	predicate	A predicate to convert.

Returns

Type	Description
Func<T, bool>	A delegate of type Func<T, TResult> referencing the same method as original predicate.

Type Parameters

Name	Description
T	Type of predicate argument.

Constant<T>(bool)

Returns a predicate which always returns the specified value.

Declaration

public static Predicate<T> Constant<T>(bool value)

Parameters

Type	Name	Description
bool	value	The value to be returned by the predicate.

Returns

Type	Description
Predicate<T>	A cached predicate always returning value.

Type Parameters

Name	Description
T	The type of the input parameter.

HasValue<T>()

Returns predicate checking that input argument of value type is not null.

Declaration

public static Predicate<T?> HasValue<T>() where T : struct

Returns

Type	Description
Predicate<T?>	The predicate instance.

Type Parameters

Name	Description
T	The type of the predicate argument.

Remarks

This method returns the same instance of predicate on every call.

IsNotNull<T>()

Returns predicate checking that input argument is not null.

Declaration

public static Predicate<T> IsNotNull<T>() where T : class?

Returns

Type	Description
Predicate<T>	The predicate instance.

Type Parameters

Name	Description
T	The type of the predicate argument.

Remarks

This method returns the same instance of predicate on every call.

IsNull<T>()

Returns predicate implementing nullability check.

Declaration

public static Predicate<T> IsNull<T>() where T : class?

Returns

Type	Description
Predicate<T>	The predicate instance.

Type Parameters

Name	Description
T	Type of predicate argument.

Remarks

This method returns the same instance of predicate on every call.

IsTypeOf<T>()

Gets a predicate that can be used to check whether the specified object is of specific type.

Declaration

public static Predicate<object?> IsTypeOf<T>()

Returns

Type	Description
Predicate<object>	The predicate instance.

Type Parameters

Name	Description
T	The target type.

Negate<T>(Predicate<T>)

Returns a predicate which negates evaluation result of the original predicate.

Declaration

public static Predicate<T> Negate<T>(this Predicate<T> predicate)

Parameters

Type	Name	Description
Predicate<T>	predicate	The predicate to negate.

Returns

Type	Description
Predicate<T>	The predicate which negates evaluation result of the original predicate.

Type Parameters

Name	Description
T	Type of the predicate argument.

Or<T>(Predicate<T>, Predicate<T>)

Returns a predicate which computes logical OR between results of two other predicates.

Declaration

public static Predicate<T> Or<T>(this Predicate<T> left, Predicate<T> right)

Parameters

Type	Name	Description
Predicate<T>	left	The first predicate acting as logical OR operand.
Predicate<T>	right	The second predicate acting as logical OR operand.

Returns

Type	Description
Predicate<T>	The predicate which computes logical OR between results of two other predicates.

Type Parameters

Name	Description
T	Type of the predicate argument.

TryInvoke<T>(Predicate<T>, T)

Invokes predicate without throwing the exception.

Declaration

public static Result<bool> TryInvoke<T>(this Predicate<T> predicate, T obj)

Parameters

Type	Name	Description
Predicate<T>	predicate	The predicate to invoke.
T	obj	The object to compare against the criteria defined within the method represented by this delegate.

Returns

Type	Description
Result<bool>	true if obj meets the criteria defined within the method represented by this delegate; otherwise, false.

Type Parameters

Name	Description
T	The type of the object to compare.

Xor<T>(Predicate<T>, Predicate<T>)

Returns a predicate which computes logical XOR between results of two other predicates.

Declaration

public static Predicate<T> Xor<T>(this Predicate<T> left, Predicate<T> right)

Parameters

Type	Name	Description
Predicate<T>	left	The first predicate acting as logical XOR operand.
Predicate<T>	right	The second predicate acting as logical XOR operand.

Returns

Type	Description
Predicate<T>	The predicate which computes logical XOR between results of two other predicates.

Type Parameters

Name	Description
T	Type of the predicate argument.