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

Understanding complex R objects with tools similar to str()
https://github.com/r-lib/lobstr

r

Last synced: 6 days ago
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Understanding complex R objects with tools similar to str()

• Host: GitHub
• URL: https://github.com/r-lib/lobstr
• Owner: r-lib
• License: other
• Created: 2015-03-20T20:57:44.000Z (almost 10 years ago)
• Default Branch: main
• Last Pushed: 2023-10-30T18:52:51.000Z (about 1 year ago)
• Last Synced: 2025-01-16T16:25:46.644Z (9 days ago)
• Topics: r
• Language: R
• Homepage: https://lobstr.r-lib.org/
• Size: 1.55 MB
• Stars: 304
• Watchers: 13
• Forks: 28
• Open Issues: 14
• Metadata Files:
  • Readme: README.Rmd
  • License: LICENSE
  • Code of conduct: .github/CODE_OF_CONDUCT.md

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README

        
---

output: github_document

---

```{r setup, include = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

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

  out.width = "100%"

)

library(lobstr)

```

# lobstr 

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

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

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

lobstr provides tools in the same vein as `str()`, which allow you to dig into the detail of an object.

## Installation

Install the released version of lobstr from CRAN:

``` r

install.packages("lobstr")

```

You can install the development version with:

``` r

# install.packages("pak")

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

```

## Example

### Abstract syntax trees

`ast()` draws the abstract syntax tree of R expressions:

```{r example}

ast(a + b + c)

ast(function(x = 1) {

  if (x > 0) print("Hi!")

})

```

### References

`ref()` shows hows objects can be shared across data structures by digging into the underlying __ref__erences:

```{r}

x <- 1:1e6

y <- list(x, x, x)

ref(y)

e <- rlang::env()

e$self <- e

ref(e)

```

A related tool is `obj_size()`, which computes the size of an object taking these shared references into account:

```{r}

obj_size(x)

obj_size(y)

```

### Call stack trees

`cst()` shows how frames on the call stack are connected:

```{r}

f <- function(x) g(x)

g <- function(x) h(x)

h <- function(x) x

f(cst())

```