Khan-Project

Project for Khan Academy's interview

Installation

You'll need npm and bundler for the installation. Run make install to install all dependencies.

Building the project

Run make local to build the project locally. It uses browserify to bundle all of the js and compass for the SASS.

Testing

To run tests, run make test.

Parser Decision

I initially wanted to use Acorn as my parser after doing some research for multiple reasons:

• It's half the size of Esprima
• It's slightly faster than Esprima

Source: http://marijnhaverbeke.nl/blog/acorn.html
I ran into compatibility problems with my current dev setup(I really wanted to learn Browserify! I also wanted a lightweight package manager): acornjs/acorn#232 . I didn't want to waste time so I chose Esprima instead.

Esprima was a solid alternative. This was because it was more mature, and there were a lot more resources(online demo especially) on their website. It's also heavily tested and is maintained by jQuery. I was also very happy with the simple documentation.

Current functionality

The demo currently supports the following statements(listed in src/js/statement.js):

• For statements
• While statements
• If statements
• Switch statements
• Try statements
• Do while statements
• Expressions
• Variable declarations

For the structure matching constraint, it is fairly loose while matching. That is, if it's looking for

[{ 
  type: 'ForStatement', 
  children: [{ type: 'ForStatement' }] 
}]

It would pass for

for (;;) {
  if (true) {
    for (;;) {
      console.log('This passes!');
    }
  }
}

However, all children must be at the same level. This would fail:

[{
  type: 'ForStatement'
}, {
  type: 'ForStatement'
}]
...
for (;;) {}
if (true) {
  for (;;) {}
}

TODO's

Minify the JavaScript code.