How much do I love the yield statement?

Quite simply, a lot. The yield statement seems to be such a simple part of C# yet it can provide such amazing power (being delayed enumeration). Outside of that power however, it can provide beautiful simplicity.

Take the following abstract class for example:

namespace MyApplication.Diagnostics
{
    using System;
    using System.Collections.Generic;

    public abstract class DiagnosticTask
    {
        public abstract IEnumerable<DiagnosticTaskResult> ExecuteAll();

        public abstract DiagnosticTaskResult ExecuteStep(Guid id);

        public virtual String Description
        {
            get
            {
                return String.Empty;
            }
        }

        public abstract Guid Id
        {
            get;
        }

        public abstract IEnumerable<DiagnosticTaskStep> Steps
        {
            get;
        }

        public virtual Boolean SupportsSingleStepExecution
        {
            get
            {
                return false;
            }
        }

        public abstract String Title
        {
            get;
        }
    }
}

The design of this abstract class allows for a diagnostic task to have multiple steps. My first implementation of this class however is one that only had a single hard-coded step. Enter the wonderful yield return statement.

public override IEnumerable<DiagnosticTaskStep> Steps
{
    get
    {
        yield return _validateStep;
    }
}

This is so much more elegant than creating a new collection to return the single predetermined item. I can’t say how much I love the yield statement.

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