List.Generate
List.Generate(initial as function, condition as function, next as function, optional selector as nullable function) as list
Generates a list of values using the provided functions. The initial
function generates a starting candidate value, which is then tested against condition
. If the candidate value is approved, then it's returned as part of the resulting list, and the next candidate value is generated by passing the newly approved value to next
. Once a candidate value fails to match condition
, the list generation process stops. An optional parameter, selector
, may also be provided to transform the items in the resulting list.
Create a list by starting at ten, repeatedly decrementing by one, and ensuring each item is greater than zero.
Usage
List.Generate(() => 10, each _ > 0, each _ - 1)
Output
{10, 9, 8, 7, 6, 5, 4, 3, 2, 1}
Generate a list of records containing x and y, where x is a value and y is a list. x should remain less than 10 and represent the number of items in the list y. After the list is generated, return only the x values.
Usage
List.Generate(
() => [x = 1, y = {}],
each [x] < 10,
each [x = List.Count([y]), y = [y] & {x}],
each [x]
)
Output
{1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}