R: Operations on Stacks/Queues

stackqueue {filehash} | R Documentation

## Operations on Stacks/Queues

### Description

Functions for interacting with stack and queue data structures implemented using `filehash` databases.

### Usage

    push(db, val, ...)
    mpush(db, vals, ...)
    pop(db, ...)
    top(db, ...)
    isEmpty(db, ...)

### Arguments

`db` | an object of class `"stack"` or `"queue"`
`val` | an R object
`vals` | a list of R objects
`...` | arguments passed to other methods

### Details

Note that for `mpush`, if `vals` is not a list it will be coerced to a list via `as.list`. Currently, `mpush` is only implemented for `"stack"`s.

### Value

`push` and `mpush` return nothing useful; `pop` returns a value from the stack/queue and deletes that value from the stack/queue; `top` returns the "top" value from the stack/queue; `isEmpty` returns `TRUE`/`FALSE` depending on whether the stack/queue is empty or not. Both `pop` and `top` signal an error if the stack/queue is empty.

### Author(s)

Roger D. Peng rpeng@jhsph.edu

[Package filehash version 2.4-1 Index]