fix: overload get method definition (help needed)

[danielwpz]

The current get method in both storage and persist map has return type V | null.
However, if a defaultValue of type V is provided, it won't return null.

I tried to fix the declaration of get method with function overloading but get an error when compiling:
ERROR TS2391: Function implementation is missing or not immediately following the declaration.
But similar code can compile if using plain typescript.

Doesn't assembly script support function overloading or I did it wrong?

[willemneal]

The default value in storage.get is null by default.

[willemneal]

AS currently doesn't support overloading (though I've been thinking of looking into myself as I have come across a lot of places that could use it). The reason that the overloading work stalled is because (especially early in the project) the desire to stay close to TS's syntax was very important.

I agree it's annoying but for now we can either add another method getWithDefault that isn't nullable, or at the call site you can cast it. E.g.

let x = map.get<string>("hello", "world") as string

Note you can also use ! like typescript but while in TS this informs the compiler to make it non-null, it's a runtime check for AS.

```ts
let x = map.get<string>("hello", "world")! // Runtime check in AS that will abort if null.

[danielwpz]

@willemneal thanks for the quick reply! Yeah when I came across this issue I did add an ! mark to explicitly tell the compiler the return value won't be null.
Add a getWithDefault method is definitely a solution, but i'm still wondering if we have a plan to support method overloading in AS? Since it has been in typescirpt for a while and is actually very useful 😎

[willemneal]

@danielwpz You could make a comment here AssemblyScript/assemblyscript#816

It's been a goal for sometime but no one has taken the time to figure it out and still make ts happy.