Adding predicates or If specific if statement

[julienasp]

I was coding a feature today, and i came across one specific usecase.

I have optional arguments given at run time. in my case it was Skip and Take.

so if provided i needed to update my IEnumerable to match the provided settings.

for the Skip it was easy:

foreach( var i in Enumerator.Skip(maybeSkip ?? 0) )

but for the take, there's no default, so it would be
foreach( var i in Enumerator.Skip(maybeSkip ?? 0) .Take(maybeTake ?? Enumerator.Count))

or i could do something like:

if(maybeSkip.hasvalue) then update Iterator
if(maybeTake.Hasvalue) then update iterator

BUT

it would be nice to be able to chain conditionnal LinqMethods like:

var iterator
.TakeIf(count, ApplyTakePredicateFunc
.SkipIf(count, ApplySkipPredicateFunc)
.OrderByIf(x => Name, ApplyOrderByPredidateFunc)

you see the picture.

or just having an IF extension like :

public static IEnumerable If(
this IEnumerable source,
bool condition,
Func<IEnumerable, IEnumerable> branch)
{
return condition ? branch(source) : source;
}

[viceroypenguin]

mmm.... I'd probably prefer

public static IEnumerable<T> TransformIf(
  this IEnumerable<T> source,
  bool condition,
  Func<IEnumerable<T>, IEnumerable<T>> transformer);

I probably won't take the time to implement, because I've never found a need for it; but I can see the value of it, so if you want to submit a PR for it, I'll take it.