Returns the series at its previous position.
back series
series - The series argument. (must be: series port)
If the series is at its head, it will remain at its head. BACK will not go past the head, nor will it wrap to the tail.
print back tail "abcd" d
str: tail "time" until [ str: back str print str head? str ] e me ime time
blk: tail [1 2 3 4] until [ blk: back blk print first blk head? blk ] 4 3 2 1
head - Returns the series at its head.
head? - Returns TRUE if a series is at its head.
last - Returns the last value of a series.
next - Returns the series at its next position.
tail - Returns the series at the position after the last value.
tail? - Returns TRUE if a series is at its tail.