List methods

Methods are called with dot syntax: list.method(args).

length

Returns the number of elements.

let n = [1, 2, 3].length()   // 3

Applies a function to each element and returns a new list. The callback must have an explicit return type.

let nums   = [1, 2, 3]
let doubled = nums.map(lambda(Int x) -> Int: x * 2)

let strings = ["1", "2", "3"]
let parsed  = strings.map(toInt)

Returns a new list containing only elements for which the callback returns true.

let evens = [1, 2, 3, 4].filter(lambda(Int x) -> Boolean: x % 2 == 0)

Folds the list into a single value. The callback takes an accumulator and the current item.

let sum = [1, 2, 3, 4].reduce(lambda(Int acc, Int x) -> Int: acc + x)

Concatenates all elements into a string with a separator.

let s = ["a", "b", "c"].join(", ")   // "a, b, c"

Appends an element to the end of the list. Mutates in place.

let List<Int> nums = [1, 2, 3]
nums.push(4)   // [1, 2, 3, 4]

Removes and returns the last element.

let x = nums.pop()   // x = 4, nums = [1, 2, 3]

Inserts an element at the beginning of the list. Mutates in place.

nums.pushFront(0)   // [0, 1, 2, 3]

Removes and returns the first element.

let x = nums.popFront()   // x = 0, nums = [1, 2, 3]

Removes the element at the given index. Mutates in place.

nums.delete(1)   // removes index 1