QuickJSR

A portable, lightweight, zero-dependency JavaScript engine for R, using QuickJS.

Values and objects are directly passed between R and QuickJS, with no need for serialization or deserialization. This both reduces overhead allows for more complex data structures to be passed between R and JavaScript - including functions.

Installation

You can install the development version of QuickJSR from GitHub with:

# install.packages("remotes")
remotes::install_github("andrjohns/QuickJSR")

Or you can install pre-built binaries from R-Universe:

install.packages("QuickJSR", repos = c("https://andrjohns.r-universe.dev",
                                        "https://cran.r-project.org"))

Usage

For standalone or simple JavaScript code, you can use the qjs_eval() function:

library(QuickJSR)

qjs_eval("1 + 1")
#> [1] 2

qjs_eval("Math.random()")
#> [1] 0.7065871

For more complex interactions, you can create a QuickJS context and evaluate code within that context:

ctx <- JSContext$new()

Use the $source() method to load JavaScript code into the context:

# Code can be provided as a string
ctx$source(code = "function add(a, b) { return a + b; }")

# Or read from a file
writeLines("function subtract(a, b) { return a - b; }", "subtract.js")
ctx$source(file = "subtract.js")

Then use the $call() method to call a specified function with arguments:

ctx$call("add", 1, 2)
#> [1] 3

ctx$call("subtract", 5, 3)
#> [1] 2

You can also pass R functions to be evaluated using JavaScript arguments:

ctx$source(code = "function callRFunction(f, x, y) { return f(x, y); }")
ctx$call("callRFunction", function(x, y) x + y, 1, 2)
#> [1] 3

ctx$call("callRFunction", function(x, y) paste0(x, ",", y), "a", "b")
#> [1] "a,b"