R6 Class - A First-In-First-Out Abstract Data Type

Implements the queue abstract data type. The last element added to this queue is the last one to be returned from it.

Methods

Public methods

• Queue$push()

• Queue$pop()

• Queue$empty()

• Queue$size()

• Queue$get()

• Queue$remove()

• Queue$print()

• Queue$clone()

---

Method push()

Adds another element to this queue.

Usage

Queue$push(new_elements)

Arguments

new_elements

the elements to be added to this queue

Returns

invisibly self

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Method pop()

Returns the first added element to this queue and removes it from this queue.

Usage

Queue$pop()

Returns

the first added element to this queue or NULL if this queue is empty

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Method empty()

Removes all elements from this queue.

Usage

Queue$empty()

Returns

invisibly self

---

Method size()

Returns the number of elements in this queue.

Usage

Queue$size()

Returns

the number of elements in this queue

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Method get()

Returns an array of elements in this queue. The order of elements is chronological: the first elements in the returned array is the oldest element added to this queue.

Usage

Queue$get(reversed = FALSE)

Arguments

reversed

(logical)
if TRUE then returns the First-In-First-Out order; otherwise returns the Last-In-First-Out order. Default: FALSE

Returns

the array of elements in this queue

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Method remove()

Removes the eldest occurrence of elements from this queue. Relies on implicit conversions of R types to compare a removed element with elements in this queue.

Usage

Queue$remove(elements)

Arguments

elements

the elements to remove from this queue

Returns

invisibly self

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Method print()

Prints this queue.

Usage

Queue$print(...)

Arguments

...

the additional arguments to this method, ignored

Returns

invisibly self

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Method clone()

The objects of this class are cloneable with this method.

Usage

Queue$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.