Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
This commit is contained in:
Alex A. Naanou 2020-05-03 15:18:41 +03:00
parent df2c4ea140
commit 14c26d5f83
2 changed files with 28 additions and 6 deletions

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@ -402,20 +402,34 @@ to make source printing in console more pleasant to read.
At this point we can't mix native types, for example it is not possible
to make a callable `Array` object...
For example this will produce a broken instance:
This is not possible in current _JavaScript_ implementations directly
as most builtin objects rely on "hidden" mechanics and there is no way
to combine or inherit them.
To illustrate:
```javascript
var CallablaArray = object.Constructor('CallablaArray', Array, function(){ .. })
// produces an Array that looks like a function but does not act like one...
var a = Reflect.construct(Array, [], Function)
// creates a function that looks like an array...
var b = Reflect.construct(Function, [], Array)
```
This will produce an instance broken in a different way:
So these will produce partially broken instances:
```javascript
var CallablaArray = object.Constructor('CallablaArray', Array, {
var A = object.Constructor('A', Array, function(){ .. })
var B = object.Constructor('B', Array, {
__call__: function(){ .. },
})
```
Some of this is due to how _object.js_ is currently implemented, this
needs further investigation...
Essentially this issue and the inability to implement it without
emulation, shows the side-effects of two "features" in _JavaScript_:
- lack of multiple inheritance
- _hidden_ protocols/functionality (namely: calls, attribute access)
Still, this is worth some thought.

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@ -513,6 +513,14 @@ function(context, constructor, ...args){
// X = Constructor('X', Array, function(){})
// ...can we "mix" disibilar types in JS, if yes then how do we
// construct the instance -- which constructor do we call???
// ..this appears not to be possible as:
// 1) Reflect.construct(Function, [], Array)
// will produce a callable object with access to all the
// array methods but none of the low-level mechanics, thus
// part of the methods will break like .push(..)
// 2) Reflect.construct(Array, [], Function)
// will produce an array instnace that looks like a function
// but is not callable...
// XXX revise .toString(..) definition test...
var Constructor =
module.Constructor =