Can we put more information into AssertedParameterScope ?

[arai-a]

Another extension for https://github.com/binast/ecmascript-binary-ast/issues/50

The requirement on the implementation is following:
https://bugzilla.mozilla.org/show_bug.cgi?id=1475458

To satisfy it without changing the implementation (this is just for reference. I'm also thinking about changing implementation side), the following structure is necessary:

enum ParameterKind {
    "simple",
    "default",
    "destructuring",
    "destructuring default",
    "rest",
    "destructuring rest"
};

interface AssertedParameterName {
  attribute unsigned short index;
  attribute ParameterKind kind;
  attribute IdentifierName name;
  attribute boolean isCaptured;
};

interface AssertedParameterScope {
  attribute FrozenArray<AssertedParameterName> paramNames;
  attribute boolean hasDirectEval;
};

index is where the binding is defined in parameters list.

for example, function f(a, b=10, {c}, [d, e] = [], f, ...g) {} has the following scope data:

AssertedParameterScope {
  paramNames: [
    AssertedParameterName {
      index: 0, kind: "simple", name: "a", isCaptured: false
    },
    AssertedParameterName {
      index: 1, kind: "default", name: "b", isCaptured: false
    },
    AssertedParameterName {
      index: 2, kind: "destructuring", name: "c", isCaptured: false
    },
    AssertedParameterName {
      index: 3, kind: "destructuring default", name: "d", isCaptured: false
    },
    AssertedParameterName {
      index: 3, kind: "destructuring default", name: "e", isCaptured: false
    },
    AssertedParameterName {
      index: 4, kind: "simple", name: "f", isCaptured: false
    },
    AssertedParameterName {
      index: 5, kind: "rest", name: "g", isCaptured: false
    },
  ],
  hasDirectEval: false
}

Also, we need bodyScope before param.

[syg]

I like #50, but this doesn't feel right to standardize in the format.

[arai-a]

okay, I'll think about more lightweight solution.