cumsub

cumsub, function

def process cumsub(
    item:     text,
    stock:    number,
    quantity: number,
    rank:     number)  : number

Computes remaining stock per item by processing bundles ordered by increasing rank. If the current stock covers the bundle’s total quantity, it decrements the stock; otherwise it outputs -(S+1) where S is the current stock.

• item: the item identifier; all lines with the same item belong together.
• stock: the initial stock for the item (identical across lines with the same item).
• quantity: the required quantity for each line.
• rank: the bundle identifier; each (item, rank) pair must be unique.

Examples

table G = with
  [| as Item, as Stock, as Quantity, as Rank |]
  [| "A", 10, 4, 1 |]
  [| "B", 5, 2, 1 |]
  [| "A", 10, 3, 2 |]
  [| "B", 5, 3, 2 |]
  [| "A", 10, 2, 3 |]
  [| "B", 5, 1, 4 |]

G.Remaining = cumsub(G.Item, G.Stock, G.Quantity, G.Rank)

show table "Result inventory" with
  G.Item
  G.Stock
  G.Quantity
  G.Rank
  G.Remaining

Output: