https://github.com/jimhester/typecheck

The typeCheck package automatically adds type checking code when types are annotated.
https://github.com/jimhester/typecheck

Last synced: about 2 months ago
JSON representation

The typeCheck package automatically adds type checking code when types are annotated.

• Host: GitHub
• URL: https://github.com/jimhester/typecheck
• Owner: jimhester
• License: other
• Created: 2016-09-12T20:03:14.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2020-07-15T10:56:38.000Z (over 4 years ago)
• Last Synced: 2024-08-13T07:14:45.264Z (4 months ago)
• Language: R
• Size: 37.1 KB
• Stars: 29
• Watchers: 6
• Forks: 2
• Open Issues: 5
• Metadata Files:
  • Readme: README.Rmd
  • License: LICENSE

Awesome Lists containing this project

README

        
---

output: github_document

---

```{r, echo = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "README-"

)

```

## Type Check ##

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

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

Type check allows use of [types](https://github.com/jimhester/types) to

automatically add checking code when types are annotated.

### Defining Types ###

`type_define()` is used to define a new type. The `check` argument specifies

a function used to verify the objects type. `type_check` adds the checks to a

specific function.

```{r error = TRUE}

type.numeric <- type_define(check = is.numeric)

f <- type_check(function(x = ? numeric) x)

f(1)

f("txt")

```

Types are defined as methods of the `type` generic. This means they follow the

same properties as normal S3 methods and can be exported and imported

to and from packages like all other functions.

The `error` argument is used to specify a custom error message for a type.

```{r error = TRUE}

type.numeric <- type_define(

  check = is.numeric,

  error = function(obj_name, obj_value, type) {

     sprintf("%s: '%s' is not a number!", obj_name, obj_value)

  })

f <- type_check(function(x = ? numeric) x)

f("txt")

```

### Packages ###

When writing a package adding a call to `typeCheck::type_check_package()`

anywhere outside a function will add type checks to all functions in the

package. Functions without type annotations are unaltered.

This means it is easy to add annotations in a stepwise process to existing

packages.

If you are using [roxygen2](https://github.com/klutometis/roxygen) You can use

the following `importFrom` statement (or use the equivalent `importFrom()` call directly

in the `NAMESPACE` file.)

```{r eval = FALSE}

f <- function(x = ? numeric) x

#' @importFrom typeCheck type type_define

typeCheck::type_check_package()

```