cache_engines {knitr} | R Documentation

## Cache engines of other languages

### Description

This object controls how to load cached environments from languages other than R (when the chunk option `engine` is not `'R'`). Each component in this object is a function that takes the current path to the chunk cache and loads it into the language environment.

### Usage

    cache_engines

### Format

An object of class `list` of length 5.

### Details

The cache engine function has one argument `options`, a list containing all chunk options. Note that `options$hash` is the path to the current chunk cache with the chunk's hash, but without any file extension, and the language engine may write a cache database to this path (with an extension).

The cache engine function should load the cache environment and should know the extension appropriate for the language.

### References

See https://github.com/rstudio/reticulate/pull/167 for an implementation of a cache engine for Python.

[Package knitr version 1.22 Index]