rstackdeque (version 1.1.1)

without_top: Return a version of an rstack without the top element

Description

Simply returns a version of the given stack without the top element. Results in an error if the structure is empty. The original rstack is left alone.

Usage

without_top(s, ...)

Arguments

s

rstack to remove elements from.

...

additional arguments to be passed to or from methods (ignored).

Value

version of the stack with the top $n$ elements removed.

Details

Runs in $O(1)$ time worst case.

References

Okasaki, Chris. Purely Functional Data Structures. Cambridge University Press, 1999.

See Also

insert_top for inserting elements.

Examples

s <- rstack()
s <- insert_top(s, "a")
s <- insert_top(s, "b")
s <- insert_top(s, "c")

s2 <- without_top(s)
print(s2)

print(s)