APP_NEW/lib/Extension/iterable.dart

import 'package:flutter/material.dart';

extension IterableExt on Iterable<Widget> {
  Iterable<Widget> separator(Widget element) sync* {
    final iterator = this.iterator;
    if (iterator.moveNext()) {
      yield iterator.current;
      while (iterator.moveNext()) {
        yield element;
        yield iterator.current;
      }
    }
  }

  Iterable<Widget> padding(EdgeInsetsGeometry padding) sync* {
    final iterator = this.iterator;
    while (iterator.moveNext()) {
      yield Padding(
        padding: padding,
        child: iterator.current,
      );
    }
  }

  Iterable<Widget> firstPadding(EdgeInsetsGeometry padding) sync* {
    final iterator = this.iterator;
    bool isFirst = true;
    while (iterator.moveNext()) {
      if (isFirst) {
        isFirst = false;
        yield Padding(
          padding: padding,
          child: iterator.current,
        );
      } else {
        yield iterator.current;
      }
    }
  }

  Iterable<Widget> lastPadding(EdgeInsetsGeometry padding) sync* {
    final iterator = this.iterator;
    Widget? previous;
    while (iterator.moveNext()) {
      if (previous != null) yield previous;
      previous = iterator.current;
    }
    yield Padding(
      padding: padding,
      child: previous,
    );
  }
}