https://github.com/krlmlr/scalar

Scalars
https://github.com/krlmlr/scalar

r

Last synced: 20 days ago
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Scalars

• Host: GitHub
• URL: https://github.com/krlmlr/scalar
• Owner: krlmlr
• Archived: true
• Created: 2019-10-27T17:34:36.000Z (about 5 years ago)
• Default Branch: master
• Last Pushed: 2019-10-27T17:34:52.000Z (about 5 years ago)
• Last Synced: 2024-08-13T07:15:29.094Z (4 months ago)
• Topics: r
• Language: R
• Size: 6.84 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.Rmd

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• jimsghstars - krlmlr/scalar - Scalars (R)

README

        
---

output: github_document

---

```{r, include = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "man/figures/README-",

  out.width = "100%"

)

library(tidyverse)

pkgload::load_all()

```

# scalar

[![Lifecycle: experimental](https://img.shields.io/badge/lifecycle-experimental-orange.svg)](https://www.tidyverse.org/lifecycle/#experimental)

The goal of scalar is to provide a [vctrs](https://vctrs.r-lib.org/) compatible way to indicate that a vector is intended to have length one.

## Installation

You can install the released version of scalar from [CRAN](https://CRAN.R-project.org) with:

``` r

install.packages("scalar")

```

## Example

This class is useful to distinguish between scalars and vectors when creating one-row tibbles that contain arbitrary objects, e.g. results of `rowwise()`-like computations.

```{r example}

library(scalar)

wrap_unless_scalar <- function(x) {

  if (is_scalar(x)) return(x)

  list(x)

}

tibble_row <- function(...) {

  lst <- tibble::lst(...)

  row <- purrr::map(lst, wrap_unless_scalar)

  tibble(!!!row)

}

tibble_row(a = 1, b = 2:3, c = list(4))

tibble_row(a = scalar(1), b = 2:3, c = scalar(list(4)))

```

Non-scalars are rejected. Concatenation returns a "bare" object.

```{r example2, error = TRUE}

scalar(1:2)

vec_c(scalar(1), scalar(2))

```