container (version 1.0.5)

pop: Get and Remove Element

Description

Search and return an element and remove it afterwards from the object. If the element is not found, signal an error.

Usage

ref_pop(.x, ...)
ref_popleft(.x, ...)
# S3 method for Deque
ref_pop(.x, ...)
# S3 method for Deque
ref_popleft(.x, ...)
# S3 method for Container
ref_pop(.x, index, ...)
# S3 method for dict.table
ref_pop(.x, index, ...)

Value

For Deque the first (ref_popleft) or last (ref_pop) element of the deque after it was removed.

For Container the value at the given index after it was removed from the Container object. If index is not found, an error is raised.

For dict.table, returns the column at the given index after it was removed from the dict.table. If column does not exist, an error is raised.

Arguments

.x

any R object.

...

additional arguments to be passed to or from methods.

index

character name or numeric position of value to be popped

Details

All functions work by reference, that is, the original object is altered. ref_pop(.x) tries to access specific values.

ref_popleft(.x) pops first element of a Deque.

See Also

peek()

Examples

# Deque
d = deque(1, 2, 3)
ref_pop(d)
ref_popleft(d)

try({
ref_pop(deque())  # pop at empty Deque
})

# Container
co = container(a = 1, b = 1:3, d = "foo")
ref_pop(co, "b")
ref_pop(co, 1)

try({
ref_pop(co, "x")  # index 'x' not found
})

# dict.table
dit = dict.table(a = 1:3, b = 4:6)
ref_pop(dit, "a")
ref_pop(dit, 1)

try({
ref_pop(dit, "x")  # index 'x' not found
})