Method Throw

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Throw<TSource>(Exception)

Returns a sequence that throws an exception upon enumeration.

Declaration
public static IEnumerable<TSource> Throw<TSource>(Exception exception)
Parameters
Type Name Description
Exception exception

Exception to throw upon enumerating the resulting sequence.
Returns
Type Description
IEnumerable<TSource>

Sequence that throws the specified exception upon enumeration.
Type Parameters
Name Description
TSource

Source sequence element type.
Remarks

The provided value (exception) will be thrown when the first element is enumerated.

If the returned IEnumerable<T> is enumerated multiple times, the same value will be thrown each time.

Examples

The following code example demonstrates how to create a sequence that throws on enumeration using Throw.

// this sequence will throw an exception on the 6th element
var sequence = Enumerable.Range(1, 5).Select(i => i.ToString())
    .Concat(SuperEnumerable.Throw<string>(new InvalidOperationException()));

// Use a function to determine how to handle an exception
var result = sequence
    .Catch(
        (InvalidOperationException ex) => SuperEnumerable.Return(ex.Message));

Console.WriteLine(
    "[" + 
    string.Join(", ", result) +
    "]");

// This code produces the following output:
// [1, 2, 3, 4, 5, Operation is not valid due to the current state of the object.]
Exceptions
Type Condition
ArgumentNullException

exception is null.