Saturday, October 26, 2013

Javascript as a language is really darn good

If you look at computer languages as tools to help you convert thought to code (ignoring other real-world practical considerations such as efficiency, developer availability, platform pervasiveness, library availability, etc...) then my opinion is that Javascript (in the form of node.js as we know it today) really stands out. Let me explain why I feel so.
  1. Javascript is a small and minimal language with few (redundant) constructs and can be taught and remembered easily. This is useful for someone who is trying to use javascript to write code as well as someone who is trying to read javascript code. When you are expressing your ideas, you want to know what tools you have and want to be able to fit them in your head. At the same time, when you (or someone else) (re)visit(s) your code, you want the reverse transfer of information (i.e. code to idea) to be quick and unambiguous and the reader shouldn't get confused trying to figure out the language syntax and semantics. To explain,

    • The fact that functions are first-class objects and that the lambda syntax isn't different (or otherwise special) compared to the standard function definition syntax helps.
    • As does the fact that objects/maps (hashes), arrays, etc... all have the same get/set syntax.

  2. There's very little fluff in the language. Most keywords don't feel like they're useless. The only ones I find excessive are 'new', 'prototype', and 'function'. Coffeescript solves this to some extent.
What this means is that it's very easy to get started with your first program once you have an idea of what it is that you want to express in code. Javascript lends itself well to elegant code.

Since there is no main() function in a node.js script, you don't need to encode all your executable code in a main() function. You won't believe how incredibly useful I find this even though I have programmed in C and am used to that style of programming. This also means that each file can have its own test() function that is run by just invoking:
$ node file_name.js.

Declaring arrays and objects (maps) in javascript is really easy, and anything that can be reasonable done in 1 line is done in one line. For example, declaring an array a that has 4 elements, 44, 31, 21, and 23 is:
var a = [ 44, 31, 21, 23 ];

Declaring an object o that maps key 'name' to 'blogger', key 'url' to '', and key 'age' to 5 is as simple as:
var o = {
  'name': 'blogger',
  'url': '',
  'age': 5

Notice how values in maps can be of different types. This is also true of elements in an array.

Converting a string (or any other type) to a string isn't rocket science either.
var sint = String(89);

To test my belief, I've started writing a toy regular expression parser and evaluation engine in javascript that will have some intentional holes (un-impelemented features) that you can fill up later so that you can get a feel for both how regular expressions work, as well as how javascript as a language handles.

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