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Merge pull request #2198 from kasbah/fix-js-examples 

fix indentation in javascript target examples
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Terence Parr 2018-07-24 13:00:31 -07:00 committed by GitHub
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1
contributors.txt
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@ -180,6 +180,7 @@ YYYY/MM/DD, github id, Full name, email
2017/12/03, oranoran, Oran Epelbaum, oran / epelbaum me
2017/12/20, kbsletten, Kyle Sletten, kbsletten@gmail.com
2017/12/27, jkmar, Jakub Marciniszyn, marciniszyn.jk@gmail.com
2018/01/06, kasbah, Kaspar Emanuel, kaspar@monostable.co.uk
2018/02/08, razfriman, Raz Friman, raz@razfriman.com
2018/02/11, io7m, Mark Raynsford, code@io7m.com
2018/05/15, johnvanderholt, jan dillingh johnvanderholte@gmail.com

33
doc/javascript-target.md
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@ -95,11 +95,16 @@ Let's suppose that your grammar is named, as above, "MyGrammar". Let's suppose t
Now a fully functioning script might look like the following:
```javascript
var antlr4 = require('antlr4');
var MyGrammarLexer = require('./MyGrammarLexer').MyGrammarLexer;
var MyGrammarParser = require('./MyGrammarParser').MyGrammarParser;
var MyGrammarListener = require('./MyGrammarListener').MyGrammarListener;
var input = "your text to parse here"
var chars = new antlr4.InputStream(input);
var lexer = new MyGrammarLexer.MyGrammarLexer(chars);
var lexer = new MyGrammarLexer(chars);
var tokens = new antlr4.CommonTokenStream(lexer);
var parser = new MyGrammarParser.MyGrammarParser(tokens);
var parser = new MyGrammarParser(tokens);
parser.buildParseTrees = true;
var tree = parser.MyStartRule();
```
@ -130,28 +135,28 @@ Let's suppose your MyGrammar grammar comprises 2 rules: "key" and "value". The a
In order to provide custom behavior, you might want to create the following class:
```javascript
KeyPrinter = function() {
MyGrammarListener.call(this); // inherit default listener
return this;
};
var KeyPrinter = function() {
MyGrammarListener.call(this); // inherit default listener
return this;
};
// inherit default listener
// continue inheriting default listener
KeyPrinter.prototype = Object.create(MyGrammarListener.prototype);
KeyPrinter.prototype.constructor = KeyPrinter;
// override default listener behavior
KeyPrinter.prototype.exitKey = function(ctx) {
console.log("Oh, a key!");
};
KeyPrinter.prototype.exitKey = function(ctx) {
console.log("Oh, a key!");
};
```
In order to execute this listener, you would simply add the following lines to the above code:
```javascript
...
tree = parser.StartRule() - only repeated here for reference
var printer = new KeyPrinter();
antlr4.tree.ParseTreeWalker.DEFAULT.walk(printer, tree);
...
tree = parser.StartRule() // only repeated here for reference
var printer = new KeyPrinter();
antlr4.tree.ParseTreeWalker.DEFAULT.walk(printer, tree);
```
## What about TypeScript?