R: Find head/tail that all satisfies a predicate.

head_while {purrr} | R Documentation

## Find head/tail that all satisfies a predicate.

### Description

Find head/tail that all satisfies a predicate.

### Usage

    head_while(.x, .p, ...)

    tail_while(.x, .p, ...)

### Arguments

`.x` | A list or atomic vector.
`.p` | A single predicate function, a formula describing such a predicate function, or a logical vector of the same length as `.x`. Alternatively, if the elements of `.x` are themselves lists of objects, a string indicating the name of a logical element in the inner lists. Only those elements where `.p` evaluates to `TRUE` will be modified.
`...` | Additional arguments passed on to `.f`.

### Examples

    pos <- function(x) x >= 0
    head_while(5:-5, pos)
    tail_while(5:-5, negate(pos))

    big <- function(x) x > 100
    head_while(0:10, big)
    tail_while(0:10, big)

[Package purrr version 0.2.2 Index]