% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/assert.R
\name{vec_is_list}
\alias{vec_is_list}
\alias{vec_check_list}
\alias{list_all_vectors}
\alias{list_check_all_vectors}
\alias{list_all_size}
\alias{list_check_all_size}
\title{List checks}
\usage{
vec_is_list(x)

vec_check_list(x, ..., arg = caller_arg(x), call = caller_env())

list_all_vectors(x)

list_check_all_vectors(x, ..., arg = caller_arg(x), call = caller_env())

list_all_size(x, size)

list_check_all_size(x, size, ..., arg = caller_arg(x), call = caller_env())
}
\arguments{
\item{x}{For \verb{vec_*()} functions, an object. For \verb{list_*()} functions, a
list.}

\item{...}{These dots are for future extensions and must be empty.}

\item{arg}{An argument name as a string. This argument
will be mentioned in error messages as the input that is at the
origin of a problem.}

\item{call}{The execution environment of a currently
running function, e.g. \code{caller_env()}. The function will be
mentioned in error messages as the source of the error. See the
\code{call} argument of \code{\link[rlang:abort]{abort()}} for more information.}

\item{size}{The size to check each element for.}
}
\description{
\itemize{
\item \code{vec_is_list()} tests if \code{x} is considered a list in the vctrs sense. It
returns \code{TRUE} if:
\itemize{
\item \code{x} is a bare list with no class.
\item \code{x} is a list explicitly inheriting from \code{"list"}.
}
\item \code{list_all_vectors()} takes a list and returns \code{TRUE} if all elements of
that list are vectors.
\item \code{list_all_size()} takes a list and returns \code{TRUE} if all elements of that
list have the same \code{size}.
\item \code{vec_check_list()}, \code{list_check_all_vectors()}, and \code{list_check_all_size()}
use the above functions, but throw a standardized and informative error if
they return \code{FALSE}.
}
}
\details{
Notably, data frames and S3 record style classes like POSIXlt are not
considered lists.
}
\examples{
vec_is_list(list())
vec_is_list(list_of(1))
vec_is_list(data.frame())

list_all_vectors(list(1, mtcars))
list_all_vectors(list(1, environment()))

list_all_size(list(1:2, 2:3), 2)
list_all_size(list(1:2, 2:4), 2)

# `list_`-prefixed functions assume a list:
try(list_all_vectors(environment()))
}
\seealso{
\code{\link[=list_sizes]{list_sizes()}}
}