Use 'zero' instead of 'null' & 'default', or allow 'null' to be used with value types

[YT-GameMaker]

Introduce a new keyword, zero, representing the default state of any type. It can be used to replace null and default, unifying the syntax for reference types and value types, and providing a clearer distinction between the concepts of "uninitialized" and "new()" for value types.

If zero would still introduce ambiguity or if there's a desire to avoid adding new keywords, then null can also be made applicable to value types. In many cases, null can better represent that data is invalid compared to 0 or default.

[huoyaoyuan]

default is allowed for reference types. It already has the proposed semantics.

[tannergooding]

In addition to this, null has existing meaning and semantics in places like generic contexts and could not be changed to mean this without it being breaking, nor would it be desirable because null is explicitly a concept related to pointers/references/nullable value types. It is not applicable to general value types.

default is the existing keyword, representing the default state of any type. Hence the name: default

[YT-GameMaker]

default could be misleading as "new()", especially now that structs can have user-defined parameterless constructors, default and "new()" might be different, developers might not notice this aspect.

[CyrusNajmabadi]

The same holds for 'zero'. Ultimately, developers have to learn how the language works. We don't need to introduce synonyms to avoid non-existent problems.

[CyrusNajmabadi]

Closing out. We already have a literal and an expression for this (default and default(T)).