Optional call returns references

[zenparsing]

Previously EvaluateDirectCall would either throw or return an ECMAScript language value (i.e. not a Reference), but now it can return a NilReference. And since PutValue is a no-op for NilReferences, it looks like this would be allowed:

let obj = {};
obj.foo?.() = 1;

Whereas I think we'd want a ReferenceError here.

[zenparsing]

Sorry, I messed up the example (I think the cascading behavior is confusing me).

let obj = {};
obj.foo?.() = 1;

(I'll fix the issue description as well.)

[nhz-io]

Assigning to rvalue allowed now?

[claudepache]

I haven’t yet much explored the use cases for PutValue on a Nil Reference. One could indeed throw an error instead of doing nothing, in case one thinks that it is a better semantic.

[claudepache]

Those forms are removed. They will throw the same error as obj.foo() = 1.