Convert integers to a Base64-encoded VLQ string, and vice versa. No dependencies, works in node.js or browsers, supports AMD.
Sourcemaps are the most likely use case. Mappings from original source to generated content are encoded as a sequence of VLQ strings.
A variable-length quantity is a compact way of encoding large integers in text (i.e. in situations where you can't transmit raw binary data). An integer represented as digits will always take up more space than the equivalent VLQ representation:
Integer | VLQ |
---|---|
0 | A |
1 | C |
-1 | D |
123 | 2H |
123456789 | qxmvrH |
npm install vlq
vlq.encode
accepts an integer, or an array of integers, and returns a string:
vlq.encode(123); // '2H';
vlq.encode([123, 456, 789]); // '2HwcqxB'
vlq.decode
accepts a string and always returns an array:
vlq.