R6 v2.5.0


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Encapsulated Classes with Reference Semantics

Creates classes with reference semantics, similar to R's built-in reference classes. Compared to reference classes, R6 classes are simpler and lighter-weight, and they are not built on S4 classes so they do not require the methods package. These classes allow public and private members, and they support inheritance, even when the classes are defined in different packages.


R6: Encapsulated object-oriented programming for R

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R6 is an implemention of encapsulated object-oriented programming for R, and is a simpler, faster, lighter-weight alternative to R's built-in reference classes. This style of programming is also sometimes referred to as classical object-oriented programming.

Some features of R6:

  • R6 objects have reference semantics.
  • R6 cleanly supports inheritance across packages.
  • R6 classes have public and private members.

In contrast to R's reference classes, R6 is not built on the S4 class system, so it does not require the methods package. Unlike reference classes, R6 classes can be cleanly inherited across different packages.

See the Introduction article for usage examples.


To install R6 from CRAN:


To install the development version (requires the devtools package):

devtools::install_github('r-lib/R6', build_vignettes = FALSE)


Why R6?

Why the name R6? When R's reference classes were introduced, some users, following the names of R's existing class systems S3 and S4, called the new class system R5 in jest. Although reference classes are not actually called R5, the name of this package and its classes takes inspiration from that name.

The name R5 was also a code-name used for a different object system started by Simon Urbanek, meant to solve some issues with S4 relating to syntax and performance. However, the R5 branch was shelved after a little development, and it was never released.

Functions in R6

Name Description
R6Class Create an R6 reference object generator
is.R6 Is an object an R6 Class Generator or Object?
as.list.R6 Create a list from an R6 object
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License MIT + file LICENSE
URL https://r6.r-lib.org, https://github.com/r-lib/R6/
LazyData true
BugReports https://github.com/r-lib/R6/issues
RoxygenNote 6.1.1
NeedsCompilation no
Packaged 2020-10-28 18:30:05 UTC; winston
Repository CRAN
Date/Publication 2020-10-28 19:30:02 UTC

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