Cursor Types

Cursors implement the Cursor protocol: start, item, next, at_end.

ArrayCursor

Created by: arr.cursor()

Method	Arguments	Returns	Description
start	none	Void	Reset index to 0.
item	none	Any	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 := 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