public static IEnumerable<TState> Scan<TSource, TState>(
	this IEnumerable<TSource> source,
	TState seed,
	Func<TState, TSource, TState> transformation
)

<ExtensionAttribute>
Public Shared Function Scan(Of TSource, TState) ( 
	source As IEnumerable(Of TSource),
	seed As TState,
	transformation As Func(Of TState, TSource, TState)
) As IEnumerable(Of TState)

public:
[ExtensionAttribute]
generic<typename TSource, typename TState>
static IEnumerable<TState>^ Scan(
	IEnumerable<TSource>^ source, 
	TState seed, 
	Func<TState, TSource, TState>^ transformation
)

[<ExtensionAttribute>]
static member Scan : 
        source : IEnumerable<'TSource> * 
        seed : 'TState * 
        transformation : Func<'TState, 'TSource, 'TState> -> IEnumerable<'TState> 

var result = Enumerable.Range(1, 5).Scan(0, (a, b) => a + b);