List.Generate

Last updated 3 months ago

List.Generate

Generates a list given an initial value function, a condition function, a next function, and an optional transformation function on the values.

function (initial as function, condition as function, next as function, optional selector as nullable function) as list

Description

Generates a list of values given four functions that generate the initial value initial, test against a condition condition, and if successful select the result and generate the next value next. An optional parameter, selector, may also be specified.

Category

List.Generators

Examples

Create a list that starts at 10, remains greater than 0 and decrements by 1.

List.Generate(()=>10, each _ > 0, each _ - 1)

{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.

List.Generate(()=> [ x = 1 , y = {}] , each [x] < 10 , each [x = List.Count([y]), y = [y] & {x}] , each [x])

{1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9}