peek_top<-.rstack {rstackdeque} | R Documentation |
Allows modification access to the top of a stack.
## S3 replacement method for class 'rstack'
peek_top(s, ...) <- value
s |
rstack to modify the first element of. |
... |
additional arguments to be passed to or from methods (ignored). |
value |
value to assign to the top data element. |
Runs in O(1)
worst case time. Throws an error if the rstack is empty
. Modifies the element in place (i.e., is not side-effect-free).
modified rstack.
peek_top
for accessing the top data element.
s <- rstack()
s <- insert_top(s, data.frame(a = 1, b = 1))
s <- insert_top(s, data.frame(a = 1, b = 1))
peek_top(s)$a <- 100
print(s)
peek_top(s) <- data.frame(a = 100, b = 100)