ASTQuery

Use css-like selectors for walking over AST-tree

Example

1var ast = esprima.parse('function test(){ var a, b = 0; a = 1; a += 2; b++; b--; };test();');
2var astQuery = new ASTQuery(ast, 'es5');
3astQuery.on({
4	print: function(node, message) {
5		console.log('node type is ' + node.type + ' | ' + message)
6	}
7
8	, ':: FunctionDeclaration': function(node) {
9		this.print(node, '1| ');
10	}
11
12	, ':: VariableDeclarator': function(node) {
13		this.print(node, '2| ' + node.id.name);
14	}
15
16	, ':: AssignmentExpression[operator="="]': function(node) {
17		this.print(node, '3| ' + node.left.name + "|" + node.operator);
18	}
19
20// TODO::
21//	, ':: UpdateExpression[operator="++"]': function(node) {
22//		this.print(node, '4| ' + node.argument.name + "|" + node.operator);
23//	}
24
25// TODO::
26//	, ':: :other': function(node) {
27//		console.log('  untouched node type is ' + node.type);
28//	}
29}, {prefix: '::'});
30
31astQuery.apply();
32
33// console output is:
34// > node type is FunctionDeclaration | 1|
35// > node type is VariableDeclarator | 2| a
36// > node type is VariableDeclarator | 2| b
37// > node type is AssignmentExpression | 3| a|=
38

TODO

1. ':other' pseudo-class
2. complex selector's support ('tag>tag')
3. classes support with API to adding class description
4. es6 'query' string template tag (astQuery.queryVariableDeclarator:${function(node){ return node.id.name == 'a' }})
5. 'removeListener'