Dapeng Zhang

Implement enum

1

Fixes https://github.com/Azure/autorest.csharp/issues/4579

Since we now make the serialization extendable by plugins, and the `EnumExpression` has two expressions of serializing/deserializing the enum which involves the serialization/deserialization. Previously in autorest.csharp, we never consider this...

change the array to `IReadOnlyList` since it is a public API

1

Since the `GetSerializationTypeProviders` is a public API and we never except the consumer of this method to modify the returned values, we should return it in a `IReadOnlyList`

Add an `ITypedValueExpressionFactory<T>` interface for our typed value expressions

2

Fixes https://github.com/microsoft/typespec/issues/3312 Majority of our typed value expressions will have the ctor taking a `ValueExpression` parameter, like this: ```csharp public record XExpression(ValueExpression Untyped) : TypedValueExpression(typeof(X), Untyped) ``` and we cannot...

See this log: https://dev.azure.com/azure-sdk/public/_build/results?buildId=3797335&view=logs&j=ad8522ef-ffaf-59d1-5ee5-3e85b44db816&t=237d07e5-d6e4-537a-487e-2d10838f2a6b 

This task is a follow up to https://github.com/Azure/autorest.csharp/issues/4476 and covers implementing the method bodies for json serialization methods.

The enum value could be strings, numbers or booleans, but it is modeled as `object` therefore it has boxing: https://github.com/microsoft/typespec/blob/c026a0a87fe1dc2f894834d8d3db9cc80afbec6f/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/InputEnumTypeValue.cs We have the same issue in literal values: https://github.com/microsoft/typespec/blob/c026a0a87fe1dc2f894834d8d3db9cc80afbec6f/packages/http-client-csharp/generator/Microsoft.Generator.CSharp.Input/src/InputTypes/InputLiteralType.cs We...

Some initial suggestions and feedbacks: https://github.com/microsoft/typespec/pull/3313#discussion_r1598772682

Coming from this comment: https://github.com/microsoft/typespec/pull/3313#discussion_r1598763558