On Tuesday, 4 May 2021 at 14:12:28 UTC, Paul Backus wrote:
> On Tuesday, 4 May 2021 at 14:07:47 UTC, WebFreak001 wrote:
>> however what about this code?
>> ```d
>> void foo() {
>>     alias A = B;
>>     A = C;
>> }
>> ```
>>
>> is the `A = C` in this case an AliasAssign? how would the parser differentiate between this AliasAssign and regular assignments?
>
> AliasAssign is only allowed in declaration contexts--the top level of a module, or the body of a `struct`, `class`, `template`, etc. In these contexts, a normal assignment statement is not allowed, so there is no ambiguity.

Am i wrong to think that even without this rule the difference could be made during semantic by testing if the assign lhs is an alias ?

On Tuesday, 4 May 2021 at 18:48:21 UTC, user1234 wrote:
>
> Am i wrong to think that even without this rule the difference could be made during semantic by testing if the assign lhs is an alias ?

That would break existing code. For example:

    void main() {
        int x = 123;
        int y = 456;
        alias z = x;
        z = y; // runtime assignment
        assert(x == 456);
    }

On Tuesday, 4 May 2021 at 18:59:05 UTC, Paul Backus wrote:
> On Tuesday, 4 May 2021 at 18:48:21 UTC, user1234 wrote:
>>
>> Am i wrong to think that even without this rule the difference could be made during semantic by testing if the assign lhs is an alias ?
>
> That would break existing code. For example:
>
>     void main() {
>         int x = 123;
>         int y = 456;
>         alias z = x;
>         z = y; // runtime assignment
>         assert(x == 456);
>     }

You can make the difference tho. z is not a type or a compile-time sequence.

On Tuesday, 4 May 2021 at 19:04:59 UTC, user1234 wrote:
> On Tuesday, 4 May 2021 at 18:59:05 UTC, Paul Backus wrote:
>>
>> That would break existing code. For example:
>>
>>     void main() {
>>         int x = 123;
>>         int y = 456;
>>         alias z = x;
>>         z = y; // runtime assignment
>>         assert(x == 456);
>>     }
>
> You can make the difference tho. z is not a type or a compile-time sequence.

AliasAssign is not limited to just types and compile-time sequences, so I don't see why that's relevant.

On Tuesday, 4 May 2021 at 19:21:36 UTC, Paul Backus wrote:
> On Tuesday, 4 May 2021 at 19:04:59 UTC, user1234 wrote:
>> On Tuesday, 4 May 2021 at 18:59:05 UTC, Paul Backus wrote:
>>>
>>> That would break existing code. For example:
>>>
>>>     void main() {
>>>         int x = 123;
>>>         int y = 456;
>>>         alias z = x;
>>>         z = y; // runtime assignment
>>>         assert(x == 456);
>>>     }
>>
>> You can make the difference tho. z is not a type or a compile-time sequence.
>
> AliasAssign is not limited to just types and compile-time sequences,

Ah yes, this is why I thought it was possible.

> so I don't see why that's relevant.