Use of being declared variable inside its own initializer about asteria

[lhmouse]

I think that JavaScript is right. Inside the initializer of a variable, it should be considered to have been declared and visible. It is just the ReferenceError: a is not defined message that is vague and cryptic. This principle also holds in C and C++ although copying an uninitialized variable results in undefined behavior.

ATM in Asteria, in such a case the variable is considered as if it was declared as const VAR = null but I personally prefer the Node.js solution; it should be invalid to read from or write to such variables until its initialization is complete.

Note that this does not forbid referencing the variable (not reading or writing):

var a = func() { return typeof a;  };   // `a` is a function returning the type of `a`,
                                        // which is not invalid.
var b = a;   // `b` is the same function.
std.debug.print("typeof `a` is `$1`.", b());  // `function`

a = 42;
std.debug.print("typeof `a` is `$1`.", b());  // `integer`

[lhmouse]

Fixed so far. Now we get this in the REPL:

#2:1> var a = func(){ return a;  };  std.debug.print("a = $1", a);
2020-01-05 22:21:38.856 @@ asteria/src/library/bindings_debug.cpp:27
        a = <function> [[`<closure>._1() @ snippet #2:1`]]
* result #2: <void>