computelength (tail recursive)

gistfile1.fs

// Tail recursive computation of List's length 
let length list = 
    // Auxiliary function to compute length
    // It store intermediate result in acc.
    let rec lengthAux acc list = 
        match list with 
        | [] -> acc
        | _::tail -> lengthAux (acc+1) tail
    lengthAux 0 list  // invoking lengthAux with acc = 0