Pattern matching in c#

frob.cs

ParseClaimIdentifiers(@ref, claim)
	.Match(ReferenceQualifier.SpecialPaymentReferenceNumber,
		r => claim.ServiceAuthExceptionCode = ServiceAuthExceptionCodeConverter.FromAnsi(r).Adapt())
	.Match(ReferenceQualifier.OriginalReferenceNumber,
		r => claim.OriginalPayerClaimControlNumber = r)
	.Match(ReferenceQualifier.ReferralNumber,
		r => claim.ReferralNumber = r)
	.Match(ReferenceQualifier.PriorAuthorizationNumber,
		r => claim.PriorAuthorization = r)
	.Match(ReferenceQualifier.RepricedClaimReferenceNumber,
		r => claim.RepricedClaimReferenceNumber = r)
	.Match(ReferenceQualifier.AdjustedRepricedClaimReferenceNumber,
		r => claim.AdjustedRepricedClaimReferenceNumber = r)
	.Match(ReferenceQualifier.ClaimNumber,
		r => claim.ClearinghouseControlNumber = r)
	.Otherwise(r => Context.InvalidQualifierError<ReferenceQualifier>(r));


if (@ref.Qualifier() == ReferenceQualifier.SpecialPaymentReferenceNumber)
{
	claim.ServiceAuthExceptionCode = ServiceAuthExceptionCodeConverter.FromAnsi(@ref.REF02_ReferenceIdentification).Adapt());
}
else if (@ref.Qualifier() == ReferenceQualifier.OriginalReferenceNumber)
{
	claim.OriginalPayerClaimControlNumber = @ref.REF02_ReferenceIdentification;
}
else if (@ref.Qualifier() == ReferenceQualifier.ReferralNumber)
{
	claim.ReferralNumber = @ref.REF02_ReferenceIdentification;
}
else if (@ref.Qualifier() == ReferenceQualifier.PriorAuthorizationNumber)
{
	claim.PriorAuthorization = @ref.REF02_ReferenceIdentification;
}
else if (@ref.Qualifier() == ReferenceQualifier.RepricedClaimReferenceNumber)
{
	claim.RepricedClaimReferenceNumber = @ref.REF02_ReferenceIdentification;
}
else if (@ref.Qualifier() == ReferenceQualifier.AdjustedRepricedClaimReferenceNumber)
{
	claim.AdjustedRepricedClaimReferenceNumber = @ref.REF02_ReferenceIdentification;
}
else if (@ref.Qualifier() == ReferenceQualifier.ClaimNumber)
{
	claim.ClearinghouseControlNumber = @ref.REF02_ReferenceIdentification;
}
else
{
	Context.InvalidQualifierError<ReferenceQualifier>(@ref.REF02_ReferenceIdentification);
}