Match-Bracket

Find the matching bracket's position for a bracket in a code.

Install

npm install match-bracket

Usage

Given this code:

sample.js

File.prototype.getExtension = function() {
  var re = /[A-Za-z]*(\.[a-z]+)$/g;
  var matched = re.exec(this.path);
 
  if (matched) {
    var ext = matched[1];
    return ext;
  } else {
    return 'none';
  }
};

We can find the matching bracket for the first { by doing:

var matchBracket = require('match-bracket');
 
var code = require('fs').readFileSync('./sample.js');
var bracketPos = {line: 1, cursor: 42};
 
var result = matchBracket(code, bracketPos);
console.log(result);
// => {line: 11, cursor: 1}

API

matchBracket(code, bracketPos, extension)

Returns the position of the matching bracket of the bracket given by bracketPos from the code.

extension is an optional argument. It allows match-bracket to recognize comments in the code and get more accurate results.

Both bracketPos and result are in the format of:

{
  line: // line number,
  cursor: // cursor number
}

line is the line number in which the bracket appears. cursor denotes order in which the bracket appears in the line. Most IDEs display this.

Rules

• Unmatched bracket returns results with null as properties.

matchBracket('({)', {line: 1, cursor: 2});
// => {line: null, cursor: null}

• In ambiguous matches, brackets closest to each other are matched.

matchBracket('(()', {line: 1, cursor: 1});
// => {line: null, cursor: null}
 
matchBracket('(()', {line: 1, cursor: 2});
// => {line: 1, cursor: 3}

License

MIT