Gabriel Kaszewski
313a5315b1
three bug-encoding invariants, one red/green cycle each: - Coins.TrySubtract fails instead of clamping - LevelTime rejects zero (continued-run zero best-times) - SkillLevel has no zero (unowned is absence, not Level=1) plan: drop signed NetCoins; add Attempt outcome as idempotency guard
38 lines
1.3 KiB
C#
38 lines
1.3 KiB
C#
namespace Mr.BrickAdventures.Progression;
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/// <summary>
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/// A non-negative quantity of coins. Amounts only — there is no signed coin value; a shortfall is
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/// a failed subtraction the caller must handle, never a negative total.
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/// </summary>
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public readonly struct Coins : IEquatable<Coins>
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{
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public int Value { get; }
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private Coins(int value) => Value = value;
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public static Coins Of(int value) => value < 0
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? throw new ArgumentOutOfRangeException(nameof(value), value, "Coins cannot be negative.")
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: new Coins(value);
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/// <summary>
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/// Subtracts <paramref name="amount"/>. Returns false when the amount exceeds what is held,
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/// leaving <paramref name="remaining"/> untouched rather than clamping to zero.
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/// </summary>
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public bool TrySubtract(Coins amount, out Coins remaining)
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{
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if (amount.Value > Value)
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{
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remaining = this;
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return false;
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}
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remaining = new Coins(Value - amount.Value);
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return true;
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}
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public bool Equals(Coins other) => Value == other.Value;
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public override bool Equals(object? obj) => obj is Coins other && Equals(other);
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public override int GetHashCode() => Value;
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public override string ToString() => Value.ToString();
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}
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