49 lines
1.2 KiB
C#
49 lines
1.2 KiB
C#
using System.Collections;
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using System.Linq;
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namespace Unity.VisualScripting
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{
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/// <summary>
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/// Returns the first item in a collection or enumeration.
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/// </summary>
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[UnitCategory("Collections")]
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public sealed class FirstItem : Unit
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{
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/// <summary>
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/// The collection.
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/// </summary>
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[DoNotSerialize]
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[PortLabelHidden]
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public ValueInput collection { get; private set; }
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/// <summary>
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/// The first item of the collection.
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/// </summary>
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[DoNotSerialize]
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[PortLabelHidden]
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public ValueOutput firstItem { get; private set; }
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protected override void Definition()
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{
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collection = ValueInput<IEnumerable>(nameof(collection));
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firstItem = ValueOutput(nameof(firstItem), First);
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Requirement(collection, firstItem);
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}
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public object First(Flow flow)
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{
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var enumerable = flow.GetValue<IEnumerable>(collection);
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if (enumerable is IList)
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{
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return ((IList)enumerable)[0];
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}
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else
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{
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return enumerable.Cast<object>().First();
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}
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}
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}
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}
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