Extension Methods

[agrapine]

I've been programming in Dart for the last 6 months, coming from C#, and loving it...
But one thing I can't really let go. And it is such a handy tool to keep the code cleaner.

Extension Methods

so we can have some of the stuff we want without changing the underlying code

now
int index=0; [].map((value)=> {...; index++})

after
[].map((value, index)=> ...)

or immutable sort with iterator, using a comparable
[].orderBy(x=> x.field)

...

NB: I know this has been opened before, and there are quite some serious ramifications but I think the end result is worth while

[zoechi]

Dup of #9991 (#32280)

[agrapine]

worth it 👍