ideal • runtime • elements • empty

Immutable empty collection.

class empty[value element type]

implements immutable list[element type]

implements immutable set[element type]

public empty()

pass

The number of elements in the collection.

implement nonnegative size => 0

Specifies whether the collection has zero elements.

implement boolean is empty => true

Specifies whether the collection has more than zero elements. Shortcut for !is_empty.

implement boolean is not empty => false

Access the first element of the list. Assumes the list is not empty.

implement element type first()

utilities • panic("Can't access the first element of the empty list")

Access the last element of the list. Assumes the list is not empty.

implement element type last()

utilities • panic("Can't access the last element of the empty list")

implement boolean contains(element type key)

return false

Read the list's element for the specified index.

implement implicit readonly reference[element type] get(nonnegative index) pure

utilities • panic("Empty list")

Enumerates elements in some collection-defined order. This method returns a snapshot of the collection state, so subsequent mutations of the collection do not cause changes in the returned list.

implement immutable list[element type] elements()

return this

Returns an immutable copy of this list.

implement immutable empty[element type] frozen copy()

return this

Skips over the specified count of elements and returns an immutable slice that begins with count and ends with the end of this list.

implement immutable list[element type] skip(nonnegative count)

assert count == 0

return this

Returns an immutable sublist with the given the starting and ending indices.

The starting index is inclusive, the ending is exclusive.

implement immutable list[element type] slice(nonnegative begin, nonnegative end)

assert begin == 0 && end == 0

return this

Returns an immutable list with the order of the elements reversed.

implement immutable list[element type] reverse()

return this

Check whether the list has at least one element that satisfies the predicate.

implement boolean has(predicate[element type] the predicate) pure

return false