vec_assert {vctrs}R Documentation

Assert an argument has known prototype and/or size

Description

Usage

vec_assert(x, ptype = NULL, size = NULL, arg = as_label(substitute(x)))

vec_is(x, ptype = NULL, size = NULL)

Arguments

x

A vector argument to check.

ptype

Prototype to compare against. If the prototype has a class, its vec_ptype() is compared to that of x with identical(). Otherwise, its typeof() is compared to that of x with ==.

size

Size to compare against

arg

Name of argument being checked. This is used in error messages. The label of the expression passed as x is taken as default.

Value

vec_is() returns TRUE or FALSE. vec_assert() either throws a typed error (see section on error types) or returns x, invisibly.

Scalars and vectors

Informally, a vector is a collection that makes sense to use as column in a data frame. An object is a vector if one of the following conditions hold:

Otherwise an object is treated as scalar and cannot be used as a vector. In particular:

Error types

vec_is() never throws. vec_assert() throws the following errors:

Both errors inherit from "vctrs_error_assert".


[Package vctrs version 0.3.4 Index]