List.scan<'T,'State> Function (F#)
Visual Studio 2012
Applies a function to each element of the collection, threading an accumulator argument through the computation. This function takes the second argument, and applies the function to it and the first element of the list. Then, it passes this result into the function along with the second element, and so on. Finally, it returns the list of intermediate results and the final result.
Namespace/Module Path: Microsoft.FSharp.Collections.List
Assembly: FSharp.Core (in FSharp.Core.dll)
// Signature:
List.scan : ('State -> 'T -> 'State) -> 'State -> 'T list -> 'State list
// Usage:
List.scan folder state list
The following code shows how to use List.scan.
let initialBalance = 1122.73 let transactions = [ -100.00; +450.34; -62.34; -127.00; -13.50; -12.92 ] let balances = List.scan (fun balance transactionAmount -> balance + transactionAmount) initialBalance transactions printfn "Initial balance:\n $%10.2f" initialBalance printfn "Transaction Balance" for i in 0 .. List.length transactions - 1 do printfn "$%10.2f $%10.2f" transactions.[i] balances.[i] printfn "Final balance:\n $%10.2f" balances.[ List.length balances - 1]
Output
Initial balance: $ 1122.73 Transaction Balance $ -100.00 $ 1122.73 $ 450.34 $ 1022.73 $ -62.34 $ 1473.07 $ -127.00 $ 1410.73 $ -13.50 $ 1283.73 $ -12.92 $ 1270.23 Final balance: $ 1257.31
