[tcgc] support negation for scope in tcgc decorators

[tadelesh]

Support scope like !java to represent all languages except java. Real use case could refer this: https://github.com/Azure/azure-rest-api-specs/blob/4883fa5dbf6f2c9093fac8ce334547e9dfac68fa/specification/batch/Azure.Batch/routes.tsp#L133.

[live1206]

1. Use ! for negation
2. When negate multiple scopes: !(java, csharp) or !(java | csharp)
3. Since negation means excluding the defined scopes from the rest, we don't want to mix the negation usage with normal usages. So, it is illegal to write "!java, csharp"
4. If agreed with 3, we will store the negation scopes or the normal scopes into state

[tadelesh]

1. Use ! for negation
2. When negate multiple scopes: !(java, csharp) or !(java | csharp)
3. Since negation means excluding the defined scopes from the rest, we don't want to mix the negation usage with normal usages. So, it is illegal to write "!java, csharp"
4. If agreed with 3, we will store the negation scopes or the normal scopes into state

agree with 3. only allow !(java, chsarp)

another situation is setting one decorator multiple times. e.g.:

@clientName("B", "!csharp")
@clientName("A", "java")
model T {}

the result should be the later override the former: T for csharp, B for else.

[live1206]

Have we considered to avoid multiple usage of the same decorator? or we want to allow it for @clientName?

[tadelesh]

Have we considered to avoid multiple usage of the same decorator? or we want to allow it for @clientName?

see discussion here: https://github.com/Azure/typespec-azure/pull/1606#discussion_r1778791173