Interface IParameterShape

Namespace

PolyType.Abstractions

Assembly

PolyType.dll

Provides a strongly typed shape model for a given .NET method parameter, representing either an actual parameter or a member initializer.

public interface IParameterShape

Properties

AttributeProvider

Gets the provider used for parameter-level attribute resolution.

IGenericCustomAttributeProvider AttributeProvider { get; }

Property Value

IGenericCustomAttributeProvider

Remarks

Provides fast attribute resolution when using the source generator, otherwise this is wrapping standard reflection-based attribute resolution.

When using the source generator, the following categories of attributes are excluded to reduce trimmed application size:

• System.Runtime.CompilerServices.* - Compiler-generated attributes
• System.Runtime.InteropServices.* - COM interop attributes
• System.Diagnostics.* - Diagnostic attributes
• System.Reflection.DefaultMemberAttribute - Default member metadata
• System.CLSCompliantAttribute - CLS compliance marker
• Microsoft.FSharp.Core.* - F# compiler generated attributes
• Attributes marked with unmet ConditionalAttribute annotations

Users requiring complete attribute resolution can use the ParameterInfo or MemberInfo properties to access standard reflection-based attribute APIs, though this will be slower.

DefaultValue

Gets the default value specified by the parameter, if applicable.

object? DefaultValue { get; }

Property Value

object

HasDefaultValue

Gets a value indicating whether the parameter has a default value.

bool HasDefaultValue { get; }

Property Value

bool

IsNonNullable

Gets a value indicating whether the parameter requires non-null values.

bool IsNonNullable { get; }

Property Value

bool

Remarks

Returns true if the parameter type is a non-nullable struct, a non-nullable reference type or the parameter has been annotated with the DisallowNullAttribute.

Conversely, it could return false if a non-nullable parameter has been annotated with AllowNullAttribute.

IsPublic

Gets a value indicating whether the parameter is a public property or field initializer.

bool IsPublic { get; }

Property Value

bool

IsRequired

Gets a value indicating whether a value is required for the current parameter.

bool IsRequired { get; }

Property Value

bool

Remarks

A parameter is reported as required if it is either a parameter without a default value or related to a property declared with the required modifier where the constructor is not annotated with SetsRequiredMembersAttribute. When IsRequired or IsRequired are set, the strictest setting wins: the parameter is reported as required if either attribute marks it as required, even if it declares a default value. An explicit IsRequired of false relaxes a parameter that would otherwise be required only for lacking a default value, but a matching IsRequired of true still takes precedence.

Kind

Gets specifies the kind of the current parameter.

ParameterKind Kind { get; }

Property Value

ParameterKind

MemberInfo

Gets the underlying MemberInfo representing the parameter, if available.

MemberInfo? MemberInfo { get; }

Property Value

MemberInfo

Remarks

Returns a PropertyInfo or FieldInfo when the parameter kind is MemberInitializer, or null otherwise.

Name

Gets the name of the method parameter.

string Name { get; }

Property Value

string

ParameterInfo

Gets the underlying ParameterInfo representing the parameter, if available.

ParameterInfo? ParameterInfo { get; }

Property Value

ParameterInfo

Remarks

Returns a value when the parameter kind is MethodParameter, or null otherwise.

ParameterType

Gets the shape of the method parameter type.

ITypeShape ParameterType { get; }

Property Value

ITypeShape

Position

Gets the 0-indexed position of the current method parameter.

int Position { get; }

Property Value

int

Methods

Accept(TypeShapeVisitor, object?)

Accepts an TypeShapeVisitor for strongly-typed traversal.

object? Accept(TypeShapeVisitor visitor, object? state = null)

Parameters

visitor TypeShapeVisitor

The visitor to accept.

state object

The state parameter to pass to the underlying visitor.

Returns

object

The object result returned by the visitor.