https://github.com/r-lib/sloop

S language OOP ⛵️
https://github.com/r-lib/sloop

r r6 s3 s4

Last synced: 3 months ago
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S language OOP ⛵️

• Host: GitHub
• URL: https://github.com/r-lib/sloop
• Owner: r-lib
• Created: 2017-02-08T18:50:26.000Z (over 7 years ago)
• Default Branch: main
• Last Pushed: 2023-10-30T17:41:43.000Z (about 1 year ago)
• Last Synced: 2024-07-22T05:45:50.387Z (4 months ago)
• Topics: r, r6, s3, s4
• Language: R
• Homepage: https://sloop.r-lib.org
• Size: 827 KB
• Stars: 101
• Watchers: 6
• Forks: 11
• Open Issues: 7
• Metadata Files:
  • Readme: README.Rmd
  • Code of conduct: .github/CODE_OF_CONDUCT.md

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• jimsghstars - r-lib/sloop - S language OOP ⛵️ (R)

README

        
---

output: github_document

---

```{r, include = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

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

)

```

# sloop 

[![CRAN status](https://www.r-pkg.org/badges/version/sloop)](https://cran.r-project.org/package=sloop)

[![R-CMD-check](https://github.com/r-lib/sloop/actions/workflows/R-CMD-check.yaml/badge.svg)](https://github.com/r-lib/sloop/actions/workflows/R-CMD-check.yaml)

[![Codecov test coverage](https://codecov.io/gh/r-lib/sloop/branch/main/graph/badge.svg)](https://app.codecov.io/gh/r-lib/sloop?branch=main)

The goal of sloop is to provide tools to help you interactively explore and understand object oriented programming in R, particularly with S3.

Please note that unlike other [r-lib](https://github.com/r-lib) packages, sloop only works with R 3.3 and later.

## Installation

You can install sloop from github with:

```{r gh-installation, eval = FALSE}

# install.packages("pak")

pak::pak("r-lib/sloop")

```

## Usage

```{r setup}

library(sloop)

```

sloop provides a variety of tools for understanding how S3 works. The most useful is probably `s3_dispatch()`. Given a function call, it shows the set of methods that are considered, found, and actually called:

```{r}

s3_dispatch(print(Sys.time()))

```

To the best of my ability it covers all the details of S3 method dispatch including group generics, internal generics, implicit classes, and use of `NextMethod()` (indicated by `->`):

```{r}

# Implicit class

x <- matrix(1:6, nrow = 2)

s3_dispatch(print(x))

# Internal generic 

length.numeric <- function(x) 10

s3_dispatch(length(x))

s3_dispatch(length(structure(x, class = "numeric")))

# NextMethod

s3_dispatch(Sys.Date()[1])

# group generic + NextMethod()

s3_dispatch(sum(Sys.Date()))

```

It also provides tools for determing what type of function or object you're dealing with:

```{r}

ftype(t)

ftype(t.test)

ftype(t.data.frame)

otype(1:10)

otype(mtcars)

otype(R6::R6Class()$new())

```

And for retrieving the methods associated with a generic or class:

```{r}

s3_methods_class("factor")

s3_methods_generic("summary")

```