function.name - functionality

[espruino-discuss]

Posted at 2021-11-20 by @SimonGAndrews

Hello,
Im looking to use Function.name in javascript. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/name
while porting the Xstate library to Expruino.

I believe Function.name or similiar is not available in Espruino.
Also a common polyfill uses function.toString() and Although Espruino does have Object.toString() which operates on a function , the returned string does not provide the name. (see attached).

Any thoughts on the possibility of implementing function.name or a workaround to get the name of a function ?
Thanks in Advance

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Attachments:

• Function_Name2.JPG
  
• Function_Name.JPG

[espruino-discuss]

Posted at 2021-11-25 by @gfwilliams

Hmm, that's a tricky one - yes function.name isn't implemented. It's a bit tricky because to do it you'd end up having to waste a variable on every function to store the name twice. For instance this is what happens in Node:

> var a = function() {}
undefined
> a.name
'a'
> var b = a;
undefined
> b.name
'a'

If all the functions you care about are in the global scope, you could run some code like this that adds name. It won't be fast but it'll work:

function hello() {
}

Object.defineProperty(Function.prototype, "name", {
  get : function(){
    for (var k in global)
      if (global[k] == this) return k;
  }});

print(hello.name)

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Posted at 2021-11-25 by @SimonGAndrews

Thanks @gfwilliams,. I get the issue now with implementing.
I appreciate your idea on the workaround and will try it out.

Really enjoying working with Espruino , Pico is great, 5v tolerance really useful.
Will be putting up on github, XState with Espruino including hierarchical states , asap.
Comming along well.