Javascript Stuck-tion, grr.

Well, once again, I'm back here asking my cyber-homies for some help.
Basically, I'm pretty much making a "word replacer". I'm writing a new browser script, and I'm creating a JS compiler. What the compiler will do is scan through a textarea and replace my script with JS. SO, after the user types in his program and clicks Compile (a button), it will document.write the program in JS. Kinda confusing?
Here:

Code:

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Step 1: I type in my program in a text area:
  EX:
  <$ a = 8
  <$ b = 4
  [?echo<< a + b;
  It makes 2 variables, and writes the sum of them.

Step 2: I click compile
  JS scans through my textarea and replaces <$ with "var" and [?echo<<    with "document.write(".

Step 3: It writes to the screen the program compiled into JS.

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Get it?

You'd have to make a grammar first, java has one, I don't remember what it's called. You have to make sure that your grammar is LL(1) though. Java also has a tree builder, that one I know, it's called JTB. You can use that to make your concrete parse tree.

I'm not using java though...:(

Javascript.

I thought you were trying to convert to Javascript :? You could do that with java. As far as I know there is no grammars for javascript.

http://www.tizag.com/javascriptT/jav...ng-replace.php

I used that magic thing called Google.

Anyway, this program sounds a little useless, and by that I mean totally useless. Why not write in JavaScript in the first place? And what twisted excuse for syntax is [?echo <<? Besides, a series of replace statements != a compiler.

ninja9578: I used JavaCC and JJTree last time I wrote a compiler in Java, never heard of JTB though.

Quote:

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Originally Posted by ninja9578

I thought you were trying to convert to Javascript :? You could do that with java. As far as I know there is no grammars for javascript.

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Why would JavaScript/ECMAScript/JScript etc. (they are all slightly different things) not have grammars? That would be unfair on the browser writer, would it not? Almost every major language since Algol has had an (E)BNF grammar, with a few notable exceptions such as, I think, pre-ANSI C. As such the Java grammar which name you cannot recall is likely called the "Grammar of the Java Programming Language". They don't give these things fancy names, you know.

AFAIK he's writing it in JavaScript and the output will be in JavaScript. For what it is (a long series of replace statements), JS is a reasonable choice, a good one even given it's mature regex support, given that it is a Web application.

JavaCC! Thanks, I couldn't remember the name of it. This is JTB

Quote:

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Originally Posted by ninja9578

JavaCC! Thanks, I couldn't remember the name of it. This is JTB

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Ah. JavaCC is in no way a grammar. It's a compiler compiler. Hence 'CC'.

don't use document.write()

it's horrible
and won't work properly (if at all) on XML or XHTML pages
(page structure needs to be full & valid prior to any processing)

use the DOM instead

Well, As for the syntax, it's an example. I'm changing it and playing with it. I'm also using document.write() so it clears the page with the compiled output as JS.

As for the name compiler, well it is sorta. C Compilers translate C into Binary. This translates stuff into JS. Also, when it is complete, it will be a bit much easier than JS. For non programmers.AND Thanks for the link IX, but that only replaces a 1 word. I need to know how to make it replace not just "<$", but "<< function" as well.
replace() only does one word.

Quote:

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Originally Posted by Identity X

Ah. JavaCC is in no way a grammar. It's a compiler compiler. Hence 'CC'.

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I was using the term incorrectly. The grammar is what goes into the CC.

Someguy, are you having a one to one relation between symbols in your language thing and JS? If so then all you need is a translator, if not you need a grammar.

In your example, GCC is not a translator, it's a compiler.

Code:

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c = a + b;

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compiles to

Code:

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mov eax, [a]
add eax, [b]
mov [c], eax

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Assemblers are translators (basically,) but if you have any difference in syntax from one language to another, then your program has to understand the grammar of both languages.

Oh, no. There isnt any syntax difference. I just need aword replacer so i can change "$" into "var" as well as "<<function" into "function"

Quote:

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Originally Posted by xXSomeGuyXx

Thanks for the link IX, but that only replaces a 1 word. I need to know how to make it replace not just "<$", but "<< function" as well.
replace() only does one word.

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Ever heard of that little used programming construct known as a loop?

Specifically a for loop through an array of string x-replacement y pairs (stored as, for example, two equally sized arrays of strings.)

Before you ask, I'm not writing the program for you :D