class Tokenizer
{
    tokens = [];
    index = 0;
    consume_type_text(type, text) {
        if(tokens[index].type === type && tokens[index].text === text) {
            index += 1;
            return tokens[index - 1];
        }
        return null;
    }
    consume_type(type)
    {
        if(tokens[index].type === type) {
            index += 1;
            return tokens[index - 1];
        }
        return null;
    }
};


function parseTag(tokenizer) {
    if(!tokenizer.consume_type_text("symbol", "<")) { return {null, null}; }

    let token = tokenizer.consume_type("identifier", "<")
    if(token === null) { return {null, null}; }

    // ...
    // On success, something like
    return {node, tokenizer}

}

function parse(tokens) {
    let tokenizer = new Tokenizer();
    tokenizer.tokens = tokens;
    tokenizer.index = 0;

    // We don't want to pass a reference, because it will get modified even it we don't successfully parse a tag.
    parseTag({...tokenizer});
}