peek_back.rdeque: Return the data element at the back of an rdeque

In rstackdeque: Persistent Fast Amortized Stack and Queue Data Structures

Description

Simply returns the data element sitting at the back of the rdeque, leaving the rdeque alone.

Usage

## S3 method for class 'rdeque'
peek_back(d, ...)

Arguments

d	rdeque to peek at.
...	additional arguments to be passed to or from methods (ignored).

Details

Runs in O(1) worst-case time.

Value

data element existing at the back of the rdeque.

See Also

without_back for removing the front element.

Examples

d <- rdeque()
d <- insert_front(d, "a")
d <- insert_front(d, "b")
e <- peek_back(d)
print(e)
print(d)

## Assigning to the front data element with peek_front:
d <- rdeque()
d <- insert_front(d, data.frame(a = 1, b = 1))
d <- insert_front(d, data.frame(a = 1, b = 1))

peek_back(d)$a <- 100
print(d)

peek_back(d) <- data.frame(a = 100, b = 100)
print(d)

rstackdeque documentation built on May 2, 2019, 4:15 a.m.