https://github.com/jimhester/lambda

Simple anonymous functions
https://github.com/jimhester/lambda

Last synced: 3 months ago
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Simple anonymous functions

• Host: GitHub
• URL: https://github.com/jimhester/lambda
• Owner: jimhester
• License: other
• Created: 2015-09-19T12:32:21.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2015-09-22T13:33:32.000Z (over 9 years ago)
• Last Synced: 2024-06-11T18:19:25.467Z (7 months ago)
• Language: R
• Size: 141 KB
• Stars: 20
• Watchers: 4
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.Rmd
  • License: LICENSE

Awesome Lists containing this project

README

        
---

output:

  md_document:

    variant: markdown_github

---

```{r, echo = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "README-"

)

```

# Lambda

[![Travis-CI Build Status](https://travis-ci.org/jimhester/lambda.svg?branch=master)](https://travis-ci.org/jimhester/lambda)

[![Coverage Status](https://img.shields.io/codecov/c/github/jimhester/lambda/master.svg)](https://codecov.io/github/jimhester/lambda?branch=master)

Lambda contains only one function `f()`, which allows you to write new

functions in a very compact format.

Simply write the body of the function as you would normally.  If you want a

given variable to appear as one of the arguments to the function, surround it with

`.()`.  Default arguments can be also be specified within `.()` as you normally

would in the argument list.

```{r}

library(lambda)

function(x, y) x + y

f(.(x) + .(y))

Reduce(f(.(x) + .(y)), 1:10)

add <- f(.(x) + .(y = 5))

add

add(1)

add(1, 2)

```

It works very well as a way to compactly define simple utility functions

```{r}

x <- list(1, list(NULL), 2)

compact <- f(Filter(Negate(is.null), .(x)))

compact

compact(x)

```

Or for partial function application

```{r}

f1 <- f(runif(n = rpois(1, 5), .(...)))

f1

```

## References

For a different (better?) approach to this same idea, see

[pryr::f()](https://github.com/hadley/pryr/blob/master/R/f.r).