A JavaScript port of OpenAI's CLIP byte-pair-encoding tokenizer.
import Tokenizer from "https://deno.land/x/clip_bpe@v0.0.6/mod.js";
let t = new Tokenizer();
t.encode("hello") // [3306]
t.encode("magnificent") // [10724]
t.encode("magnificently") // [9725, 2922]
t.decode(t.encode("HELLO")) // "hello "
t.decode(t.encode("abc123")) // "abc 1 2 3 "
t.decode(st.encode("let's see here")) // "let 's see here "
t.encode("hello world!") // [3306, 1002, 256]
// to encode for CLIP (trims to maximum of 77 tokens and adds start and end token, and pads with zeros if less than 77 tokens):
t.encodeForCLIP("hello world!") // [49406,3306,1002,256,49407,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]This encoder/decoder behaves differently to the the GPT-2/3 tokenizer (JavaScript version of that here). For example, it doesn't preserve capital letters, as shown above.
The Python version of this tokenizer uses the ftfy module to clean up the text before encoding it. I didn't include that module by default because currently the only version available in JavaScript is this one, which requires importing a full Python runtime as a WebAssembly module. If you want the ftfy cleaning, just import it and clean your text with it before passing it to the .encode() method.
To the extent that there is any original work in this repo, it is MIT Licensed, just like openai/CLIP.