Forward Piping with Rotating Animation

main.dart

// ignore_for_file: unreachable_from_main

import 'dart:math';
import 'package:flutter/material.dart';

extension ForwardPipeOperator<T extends Widget, T2 extends Widget> on T
    Function(Widget) {
  /// Returns a new function that applies the given transformation to the result
  /// of this function
  T Function(T2) operator |(Widget Function(Widget) next) =>
      (w) => this(next(w));
}

// These functions take advantage of Dart's tear-off syntax to achieve a 
// a similar result to F#'s forward pipe operator

MaterialApp materialApp(Widget home) => MaterialApp(
      debugShowCheckedModeBanner: false,
      home: home,
    );

Scaffold scaffold(Widget body) => Scaffold(
      body: body,
    );

Center center(Widget body) => Center(
      child: body,
    );

// This is the cool part!
void main() => runApp(
      ( materialApp |
        scaffold |
        Rotating.new |
        center )(const Text('Hello world')),
    );

class Rotating extends StatefulWidget {
  // ignore: public_member_api_docs, use_key_in_widget_constructors
  const Rotating(this.child);

  final Widget child;

  @override
  State<Rotating> createState() => _RotatingState();
}

class _RotatingState extends State<Rotating>
    with SingleTickerProviderStateMixin {
  late final AnimationController _controller;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(seconds: 2),
      vsync: this,
    )..repeat();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) => AnimatedBuilder(
        animation: _controller,
        builder: (context, child) => Transform.rotate(
          angle: _controller.value * 2 * pi,
          child: Transform.scale(
            scale: 0.8 + (_controller.value * 0.4),
            child: child,
          ),
        ),
        child: widget.child,
      );
}