https://github.com/ujihisa/jinaw

JavaScript in a week
https://github.com/ujihisa/jinaw

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JavaScript in a week

• Host: GitHub
• URL: https://github.com/ujihisa/jinaw
• Owner: ujihisa
• Created: 2013-01-01T01:12:11.000Z (almost 12 years ago)
• Default Branch: master
• Last Pushed: 2013-04-10T07:08:35.000Z (over 11 years ago)
• Last Synced: 2024-05-01T23:19:29.300Z (7 months ago)
• Language: Clojure
• Size: 172 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# JavaScript in a week

## Day 1 defining a subset of JavaScript

The implementation should execute the following JavaScript code.

```js

var acc = 'dummy';

var f = function() {

	var acc = [];

	return function(x) {

		return x ? acc.push(x)&&f(x - 1) : acc;

	};

  console.log("this won't show up!");

}();

String.prototype.ujihisa = function() {

	var x = 10;

	return this + f(x);

}

console.log("hello".ujihisa());

console.log(acc == 'dummy');

console.log({'a': 2}.a == 2);

```

    hello10,9,8,7,6,5,4,3,2,1

    true

That code covers the following important aspects.

* statements and expressions

* literals (String, Number, Function, Array and Object)

* function call, method call, operators, and index/key access of Object

* implicit convertion (String + Number)

* lexical scope (see `acc` var)

* method addition by prototype

* `return` exits from the current function

The implementation consists of

* parser (JS code to internal representation in S-expression)

* runtime

I'll work on runtime first in Clojure, then work on parser in Haskell with parsec.

### parsing

I don't implement the parser for now but I simply parse the sample code by hand. the first 2 statements will be like the below.

before:

```js

var acc = 'dummy';

var f = function() {

	var acc = [];

	return function(x) {

		return x ? acc.push(x)&&f(x - 1) : acc;

	};

}();

```

after:

```clojure

'[(var 'acc "dummy")

  (var 'f

       (call

         (function []

                   [[(var 'acc (array))

                     (return

                       (function ['x]

                                 [[(return (if 'x

                                             (and (mcall 'push 'acc ['x])

                                                  (call 'f [(minus 'x 1)]))

                                             'acc))]]))]])

         []))]

```

## What doesn't this implementation cover

* try/catch

* lots of standard classes (e.g. Date)

* browser specific features

* setTimeout

* require (like node.js's)