[Pas2js] Question regarding the future type helper feature

[silvioprog]

Hello,

Since this feature is planned to be implemented, I have a question about
the possibility to declare multiple helpers for the same type. I suspect
you will implement it extending the object prototype, but it seems multiple
type helpers are not allowed in Pascal code. For example, consider the
following code:

uses SysUtils;

begin
  ShowMessage(Integer(123).ToString);
end.

it compiles and runs fine, but, if you declare another helper:

uses SysUtils;

type
  TMyIntegerHelper = record helper for Integer
    function ToString2: string;
  end;

function TMyIntegerHelper.ToString2: string;
begin
  Result := Concat('my', IntToStr(Self));
end;

begin
  ShowMessage(Concat(Integer(123).ToString, ';', Integer(123).ToString2));
end.

it can't compile:

Unit1.pas: E2003 Undeclared identifier: 'ToString'

however, in the Pas2JS it should be supported, and the result would be:

123;my123

A small example in JS extending the Date prototype, very close to our type
helper, but allowing multiple declarations:

Date.prototype.toMyString = (function() {
  return "My " + this.toString();
});
var event = new Date("August 19, 1975 23:15:30");
console.log(event.toString(), ";", event.toMyString());

it prints:

Tue Aug 19 1975 23:15:30 GMT-0300 ; My Tue Aug 19 1975 23:15:30 GMT-0300

Many JS plugins works extending prototype, and we can use multiple plugins
simultaneously, so it should be supported in Pas2JS mode. :-)

Best,

--
Silvio Clécio
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