Cursor Types — Nex Reference

The built-in collections’ cursors. Each is a Cursor[T] (see Foundational Classes): arr.cursor() on an Array[Integer] has type Cursor[Integer], and its item is an Integer. Like every cursor, each also has cursor, which returns the cursor itself.

`ArrayCursor`

Created by: arr.cursor()

Method	Arguments	Returns	Description
`start`	none	`Void`	Reset index to `0`.
`item`	none	`T`	Return current array element; throws at end.
`next`	none	`Void`	Advance index by one if not at end.
`at_end`	none	`Boolean`	True when index is beyond last element.

`StringCursor`

Created by: str.cursor()

Method	Arguments	Returns	Description
`start`	none	`Void`	Reset index to `0`.
`item`	none	`Char`	Return current character; throws at end.
`next`	none	`Void`	Advance index by one if not at end.
`at_end`	none	`Boolean`	True when index is beyond last character.

`MapCursor`

Created by: map.cursor()

Method	Arguments	Returns	Description
`start`	none	`Void`	Refresh key snapshot and reset index.
`item`	none	`Map_Entry[K, V]`	Return the current entry (`key`, `value`); throws at end.
`next`	none	`Void`	Advance index by one if not at end.
`at_end`	none	`Boolean`	True when index is beyond key snapshot.

`Byte_Array_Cursor`

Created by: buf.cursor() on a Byte_Array (intern data/Byte_Array; see Data Libraries). This is what across buf as b do ... end uses, and b is a Byte.

Method	Arguments	Returns	Description
`start`	none	`Void`	Reset index to `0`.
`item`	none	`Byte`	Return the current byte; raises at end.
`next`	none	`Void`	Advance index by one if not at end.
`at_end`	none	`Boolean`	True when index is beyond the last byte.

Examples

let xs := [1, 2, 3]
let c: Cursor[Integer] := xs.cursor()
from c.start() until c.at_end() do
  print(c.item())
  c.next()
end

let m := {"name": "Ada", "lang": "Nex"}
let mc := m.cursor()
from mc.start() until mc.at_end() do
  let entry := mc.item()
  print(entry.key + ": " + entry.value)
  mc.next()
end