https://github.com/judofyr/duktape.rb

Ruby bindings to the Duktape JavaScript interpreter
https://github.com/judofyr/duktape.rb

duktape javascript-interpreter

Last synced: 3 months ago
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Ruby bindings to the Duktape JavaScript interpreter

• Host: GitHub
• URL: https://github.com/judofyr/duktape.rb
• Owner: judofyr
• Created: 2014-01-11T12:41:43.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2023-12-01T16:32:24.000Z (7 months ago)
• Last Synced: 2024-02-16T23:22:53.133Z (4 months ago)
• Topics: duktape, javascript-interpreter
• Language: C
• Homepage: http://www.rubydoc.info/gems/duktape
• Size: 3.67 MB
• Stars: 77
• Watchers: 4
• Forks: 7
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md

Lists

• AwesomeInterpreter - duktape.rb

README

        
# Duktape.rb

Duktape.rb is a C extension for the [Duktape](http://duktape.org/) JavaScript

interpreter.

## Quickstart

```sh

$ rake

$ ruby example.rb

```

## Usage

```ruby

require 'duktape'

# Create a new context

ctx = Duktape::Context.new

## Evaluate a string

p ctx.eval_string('1 + 1')  # => 2.0

```

### Contexts

Creating a context creates a fresh evaluation environment with no global

variables or functions defined.

A common pattern is to create a new context, define static functions once, and

reuse the context to invoke the function many times with `call_prop`.

``` ruby

ctx = Duktape::Context.new

ctx.exec_string <<-JS

  function process(str, options) {

    // ...

  }

JS

ctx.call_prop('process', 'some data', a: 1, b: 2)

```

### Call APIs

* `exec_string` - Evaluate a JavaScript String on the context and return `nil`.

* `eval_string` - Evaluate a JavaScript String expression and return the result

                  as a Ruby Object.

- `get_prop`    - Access the property of the global object and return the value

                  as a Ruby Object.

- `call_prop`   - Call a defined function with the given parameters and return

                  the value as a Ruby Object.

### Defining functions

You can define simple functions in Ruby that can be called from

JavaScript:

```ruby

ctx.define_function("leftpad") do |str, n, ch=' '|

  str.rjust(n, ch)

end

```

### Exceptions

Executing JS may raise two classes of errors: `Duktape::Error` and

`Duktape::InternalError`.

Any JS runtime error that is thrown in the interpreter is converted to a Ruby

`Duktape::Error`. Specific error subclasses, such as `SyntaxError` and

`TypeError`, are mapped from JS to the Ruby equivalent of the same name.

``` ruby

ctx = Duktape::Context.new

ctx.exec_string <