Package 'jsutils'

Parse or Tokenize JavaScript code using Esprima

Description

Use the Esprima library to parse or tokenize JavaScript code. Note that the first time this function is called, it will load the esprima library into the JavaScript context, which may take a few seconds. Subsequent calls will be faster.

Usage

esprima_parse(input, options = NULL, type = "script")

esprima_tokenize(input, options = list())

Arguments

input	Either a path to a file or a character string containing the JavaScript code to be parsed or tokenized.
options	A list of configuration options to pass to the Esprima parser or tokenizer.
type	A character string specifying the type of code to parse: "script" (default) or "module".

Value

For esprima_parse, a list representing the Abstract Syntax Tree (AST) of the parsed code. For esprima_tokenize, a list of tokens extracted from the input code.

Examples

js_code <- 'const answer = 42;'
esprima_parse(js_code)
esprima_tokenize(js_code)

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Get versions of bundled JavaScript libraries

Description

This function returns the versions of the bundled JavaScript libraries used in the package.

Usage

js_versions()

Value

A named list with the versions of Esprima, sass.js, Terser, and TypeScript.

Examples

js_versions()

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Compile SASS/SCSS to CSS using the sass.js library

Description

This function uses the sass.js library to compile SASS/SCSS code into CSS. It leverages the QuickJSR package to run JavaScript code within R. Note that the first time this function is called, it will load the sass.js library into the JavaScript context, which may take a few seconds. Subsequent calls will be faster.

Usage

sass(input, options = NULL)

Arguments

input	Either a path to a file or a character string containing the SASS/SCSS code to be compiled.
options	A list of options to pass to the sass.js compiler.

Value

A list containing the compiled CSS code and any warnings or errors.

Examples

scss_code <- "h1 { font-size: 40px; code { font-face: Roboto Mono; } }"
sass(scss_code, list(style = "compressed"))

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Minify JavaScript code using Terser

Description

Uses the Terser JavaScript library to minify JavaScript code. Note that the first time this function is called, it will load the terser library into the JavaScript context, which may take a few seconds. Subsequent calls will be faster.

Usage

terser(input, options = NULL)

Arguments

input	Either a path to a file or a character string containing the JavaScript code to be minified.
options	A list of options to pass to Terser for minification. See the Terser documentation for available options.

Value

A list containing the minified code and any warnings or errors.

Examples

js_code <- "function add(a, b) { return a + b; }"
terser(js_code, list(sourceMap = TRUE))

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Transpile TypeScript code to JavaScript

Description

This function uses the TypeScript compiler to transpile TypeScript code into JavaScript. Note that the first time this function is called, it will load the TypeScript library into the JavaScript context, which may take a few seconds. Subsequent calls will be faster.

Usage

typescript(input, options = NULL)

Arguments

input	Either a path to a file or a character string containing the TypeScript code to be transpiled.
options	A list of options to pass to the TypeScript transpiler. See the TypeScript documentation for available options.

Value

A list containing the transpiled JavaScript code and any diagnostics.

Examples

ts_code <- "const greet = (name: string): string => `Hello, ${name}!`;"
typescript(ts_code, list(compilerOptions = list(target = "ES5")))

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