Get or set language engines for evaluating code chunks and inline code.
Usage
engines(...)
Value
The usage is similar to reactor(): engines('LANG') returns an
engine function for the language LANG, and engines(LANG = function(x, inline = FALSE, ...) {}) sets the engine for a language.
Arguments
...
Named values (for setting) or unnamed values (for getting).
Details
An engine function should have three arguments:
x: An element in the crack() list (a code chunk or a text block).
inline: It indicates if x is from a code chunk or inline code.
...: Currently unused but recommended for future compatibility (more
arguments might be passed to the function).