72 lines
2.1 KiB
C#
72 lines
2.1 KiB
C#
// Example 2 solution — Weather Station domain demo of Slice with Lambda (C#), after
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//
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// Lambda extracted (step 1), slid to the top (step 2), method extracted
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// below the guard (step 3). The constructor now takes the lambda directly,
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// so tests construct with new SprinklerController(() => 200).
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//
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// Condensed mechanics: https://sammancoaching.org/refactorings/slice.html
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// (where that page says mock, we use a lambda instead).
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using System;
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public enum SunExposure
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{
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Shady,
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Sunny
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}
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public enum WateringDuration
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{
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None,
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Medium,
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Short
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}
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public class LightSensor
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{
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private readonly Random _rng = new Random(); // stand-in for hardware noise
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public byte Read()
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{
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return (byte)_rng.Next(256);
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}
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}
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public class SprinklerController
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{
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private readonly Func<byte> _readLight; // the sensor, as a lambda
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private bool _wateredToday; // event-style client state
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public SprinklerController(Func<byte> readLight)
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{
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_readLight = readLight;
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}
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public WateringDuration ScheduleWatering()
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{
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Func<byte> readLight = () => _readLight(); // lambda definition at the top
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return ScheduleWateringTail(readLight); // pass the lambda on
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}
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private WateringDuration ScheduleWateringTail(Func<byte> readLight)
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{
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if (_wateredToday) // guard: client state, stays
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{
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return WateringDuration.None;
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}
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_wateredToday = true; // set only after watering
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byte reading = readLight(); // middle: the stubbed lambda
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SunExposure exposure = ToSunExposure(reading);
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if (exposure == SunExposure.Sunny) // tail: complex behaviour below
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{ // the extraction point
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return WateringDuration.Medium;
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}
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return WateringDuration.Short;
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}
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private static SunExposure ToSunExposure(byte reading)
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{
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return reading > 128 ? SunExposure.Sunny : SunExposure.Shady;
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}
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} |